ADDITIVE STEEL ALLOYS FOR CONTOURED COOLING INSERTS, AND METHODS THEREOF

Description

INCORPORATION BY REFERENCE TO ANY PRIORITY APPLICATIONS

Any and all applications for which a foreign or domestic priority claim is identified in the Application Data Sheet or PCT Request as filed with the present application are hereby incorporated by reference under 37 CFR 1.57, and Rules 4.18 and 20.6. This application claims the benefit of U.S. Provisional Application No. 63/728,319, entitled ADDITIVE STEEL ALLOYS FOR CONTOURED COOLING INSERTS, AND METHODS THEREOF, filed on Dec. 5, 2024, which is incorporated by reference herein in its entirety for all purposes.

BACKGROUND

Field

This disclosure relates to steel alloys. More specifically, the present disclosure relates to steel alloy compositions for contoured cooling inserts used in molding apparatuses.

Description of the Related Art

Steel alloy compositions are commonly used in manufacturing of various metal products. In some manufacturing applications, a cooling insert comprising an alloy composition may be used in a mold to help form metal products. Conventional cooling inserts are typically machined (e.g., drilled) to include cooling channels, and therefore are limited with regard to the shapes, structures and orientations of the cooling channels. Using a non-conformal cooling channel, cooling is less uniform, leading to thermal gradients and uneven cooling of the cast metal product. For example, cooling efficiency of a cooling insert may be limited based on the straight machined paths of the cooling channels, which may form areas within the cooling insert where heat may accumulate.

As such, conventional cooling inserts struggle with uneven heat distribution/dissipation when forming the metal product. As such, improved cooling inserts may be beneficial.

SUMMARY

For purposes of summarizing the invention and the advantages achieved over the prior art, certain objects and advantages of the invention are described herein. Not all such objects or advantages may be achieved in any particular embodiment of the invention. Thus, for example, those skilled in the art will recognize that the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other objects or advantages as may be taught or suggested herein.

In one aspect, a steel alloy composition is described. The composition includes: C: 0.05-0.6 wt. %, Cr: 0.1-1.5 wt. %, Ni: 1.5-6 wt. %, Mn: 0.5-4.5 wt. %, Mo: 0.5-1.2 wt. %, V: 0.1-0.6 wt. %, Fe: Balance, a hardness of at least about 40 HRC, and a toughness of at least about 40 J.

In another aspect, a steel alloy composition is described. The composition includes: C: 0.05-0.6 wt. %, Ni: 0.8-6 wt. %, Mn: 0.18-4.5 wt. %, Mo: 0.5-4 wt. %, V: 0.1-0.8 wt. %, Fe: Balance, a hardness of at least about 40 HRC, and a toughness of at least about 40 J.

In some embodiments, the steel alloy composition further includes a yield strength of at least about 950 MPa at 450° C. In some embodiments, the hardness is at least about 48 HRC. In some embodiments, the steel alloy composition further includes at least about 10 vol. % martensite. In some embodiments, martensite formation begins at about 50° C.

In some embodiments, the steel alloy composition further includes: Cr: 1.1-1.3 wt. %, Ni: 1.8-2.2 wt. %, Mn: 3.5-4.5 wt. %, Mo: 1-1.2 wt. %, V: 0.4-0.6 wt. %, and Fe: Balance. In some embodiments, the steel alloy composition further includes: C: 0.18-0.32 wt. %, Ni: 1-6 wt. %, Mn: 0.5-4 wt. %, Mo: 0.6-2.8 wt. %, V: 0.1-0.75 wt. %, and Fe: Balance. In some embodiments, the steel alloy composition further includes: C: 0.08-0.35 wt. %, Ni: 0.9-4.2 wt. %, Mn: 0.18-0.52 wt. %, Mo: 2-3.7 wt. %, V: 0.2-0.62 wt. %, and Fe: Balance. In some embodiments, the steel alloy composition comprises 3.3-5.4 wt. % of Cr. In some embodiments, the steel alloy composition comprises 0.1-3.2 wt. % of Cr. In some embodiments, the steel alloy composition comprises 0.2-0.26 wt. % of C. In some embodiments, the steel alloy composition comprises 1-3.5 wt. % of Ni. In some embodiments, the steel alloy composition comprises 1-2.5 wt. % of Mo. In some embodiments, the steel alloy composition further includes W: 0.01-0.9 wt. %. In some embodiments, the steel alloy composition further includes W: 0.01-1.7 wt. %. In some embodiments, the steel alloy composition further includes Cu: 0.8-1.5 wt. %. In some embodiments, the steel alloy composition further includes Cu: 0.8-2.2 wt. %. In some embodiments, the steel alloy composition further includes Co: 0.01-6 wt. %. In some embodiments, the steel alloy composition further includes Co: 0.01-2.2 wt. %.

In some embodiments, the steel alloy composition further includes incidental impurities, wherein a total of incidental impurities is at most about 1 wt. %. In some embodiments, the incidental impurities include Si, P, S, O, or combinations thereof. In some embodiments, the steel alloy composition further including interstitial hardeners, wherein the interstitial hardeners are at most about 1 wt. % of the steel alloy composition. In some embodiments, the interstitial hardeners include C, N, or combinations thereof. In some embodiments, the steel alloy composition is a contoured cooling insert.

In another aspect, a contoured cooling insert for use in a molding apparatus is described. The contoured cooling insert includes: an insert body including a steel alloy composition, and a contoured molding surface, and a conformal cooling channel positioned within the insert body, wherein at least a portion of the conformal cooling channel conforms to the contoured molding surface.

In another aspect, a method of forming a molding apparatus is described. The method includes: positioning a contoured cooling insert within a molding apparatus, injecting a metal melt into the molding apparatus, wherein the injected metal melt contacts the contoured molding surface, passing a cooling material through the conformal cooling channel, and cooling the injected metal melt to form a cast metal product.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graph showing the toughness and hardness of various commercial alloys as well as performance windows for alloys, according to some embodiments.

FIG. 2A is a cross-sectional schematic illustration of a portion of a non-conformal cooling channel.

FIG. 2B is a cross-sectional schematic illustration of a portion of a conformal cooling channel, according to some embodiments.

FIG. 2C is a schematic illustration showing a cross-sectional view of a contoured cooling insert, according to some embodiments.

FIG. 3A is a graph showing results of temperature dependence of equilibrium amount of phases of a steel alloy composition, according to some embodiments.

FIG. 3B is a graph showing results of liquid phases at various mole fractions and temperatures of a steel alloy composition, according to some embodiments.

FIG. 3C is a graph showing results of phase transformations in a steel alloy composition based on martensite transformation temperatures and mass percent of carbon element in the steel alloy composition, according to some embodiments.

FIG. 3D is a graph showing results of compositional changes of all components in a steel alloy composition as a function of distance, according to some embodiments.

FIG. 4 is a graph showing results of phase transformations based on thermodynamic driving force and temperature, according to some embodiments.

FIG. 5 is a graph showing results of microstructure evolution of a steel alloy composition based on a coarsening rate coefficient and temperature, according to some embodiments.

FIG. 6 is a graph showing results of a Vickers hardness profile of a steel alloy composition across depth distances of the alloy surface, according to some embodiments.

FIG. 7A is a graph showing results of a Rockwell hardness profile of a steel alloy composition over time, according to some embodiments.

FIG. 7B is a graph showing results of a Rockwell hardness profile of another steel alloy composition over time, according to some embodiments.

FIG. 7C is a graph showing results of a Rockwell hardness profile of the steel alloy compositions of FIGS. 7A and 7B compared with commercial alloys over time, according to some embodiments.

FIG. 8A is a graph showing results of a Rockwell hardness profile of another steel alloy composition over time, according to some embodiments.

FIG. 8B is a graph showing results of Rockwell hardness profiles of various steel alloy compositions over time, according to some embodiments.

DETAILED DESCRIPTION

Although certain preferred embodiments and examples are disclosed below, the inventive subject matter extends beyond the specifically disclosed embodiments to other alternative embodiments and/or uses and to modifications and equivalents thereof. Thus, the scope of the claims appended hereto is not limited by any of the particular embodiments described below. For example, in any method or process disclosed herein, the acts or operations of the method or process may be performed in any suitable sequence and are not necessarily limited to any particular disclosed sequence. Various operations may be described as multiple discrete operations, in turn, in a manner that may be helpful in understanding certain embodiments; however, the order of description should not be construed to imply that these operations are order-dependent. Additionally, the structures, systems, and/or devices described herein may be embodied as integrated components or as separate components. For purposes of comparing various embodiments, certain aspects and advantages of these embodiments are described. Not necessarily all such aspects or advantages are achieved by any particular embodiment. Thus, for example, various embodiments may be carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other aspects or advantages as may also be taught or suggested herein.

Improved steel alloy compositions, which may be used to form contoured cooling inserts, are described. The contoured cooling inserts include conformal cooling channels that conform to a contoured (e.g., curved) surface of the contoured cooling insert, and therefore are able to more effectively cool a cast metal product within a mold. Due to the conformed shape of the cooling channel, a more uniform heat distribution throughout the molding apparatus is provided, reducing cycle time and improving quality of the cast metal product. By maintaining consistent and uniform temperatures across the molding surfaces, heating defects such as warping and sink marks may be prevented.

In some embodiments, the contoured cooling insert may be formed by an additive manufacturing process (e.g., 3-D printing, layered printing, deposition modeling, stereolithography, laser sintering, digital light processing, jetting, electron beam melting). However, when alloy compositions typically used to form cooling inserts were utilized in an additive manufacturing process, an increased surface roughness resulted that lead to early thermal fatigue failure (e.g., cracks formed that initiate from the cooling channel).

As such, the steel alloy compositions disclosed herein demonstrate improved properties (e.g., improved thermal stability, erosion, toughness and/or hardness), which may be able to withstand crack initiation and propagation. Such improved properties may be beneficial in numerous applications, such as a conformal cooling insert formed by an additive manufacturing processes.

Steel Alloy Compositions and Properties

The steel alloys disclosed herein were discovered to have improved hardness and toughness. The steel alloys are described herein by the weight percent (wt. %) of the total elements and particles within the alloy, as well as specific properties of the alloys. It will be understood that the remaining composition of any alloy described herein may include iron (Fe) or iron (Fe) and incidental impurities. It should be understood that if an alloy composition is described as including or comprising a balance of iron or iron and incidental impurities in addition to other element(s) (and optionally specific amounts of each other element(s)), the alloy composition may later be described as further including or comprising additional element(s) (and optionally specific amounts of each additional element(s)) where iron or iron and incidental impurities are included or comprise the remaining balance of the alloy composition with the additional element(s). In some embodiments, the steel alloy composition comprises iron (Fe) in an amount of, of about, of at least, of at least about, of at most, or of at most about, 80 wt. %, 82 wt. %, 84 wt. %, 85 wt. %, 86 wt. %, 88 wt. %, 90 wt. %, 92 wt. %, 94 wt. %, 95 wt. %, 96 wt. %, 97 wt. %, 98 wt. %, 99 wt. % or 99.5 wt. %, or any range of values therebetween.

Impurities may be present in the starting materials or introduced in one of the processing and/or manufacturing steps to create the steel alloy. Incidental impurities are compounds and/or elements that do not or do not substantially affect the material properties of the composition, such as hardness, corrosion resistance, yield strength, tensile strength, ductility, martensite formation and/or ferrite formation. In some embodiments, the incidental impurities include Si, P, S, O, or combinations thereof. In some embodiments, the total incidental impurities or other elements are, are about, are at most, or are at most about, 1 wt. %, 0.8 wt. %, 0.5 wt. %, 0.2 wt. % 0.15 wt. %, 0.1 wt. %, 0.05 wt. % or 0.01 wt. %, or any range of values therebetween. In some embodiments, each elemental incidental impurity or each additional element that is not recited is, is about, is at most, or is at most about, 0.8 wt. %, 0.5 wt. %, 0.2 wt. % 0.1 wt. %, 0.05 wt. %, 0.01 wt. %, 0.005 wt. % or 0.001 wt. %, or any range of values therebetween.

In some embodiments, the steel alloy composition comprises silicon (Si) in an amount of, of about, of at least, of at least about, of at most, or of at most about, 1 wt. %, 0.9 wt. %, 0.8 wt. %, 0.75 wt. %, 0.7 wt. %, 0.65 wt. %, 0.6 wt. %, 0.55 wt. %, 0.5 wt. %, 0.4 wt. %, 0.3 wt. %, 0.2 wt. %, 0.1 wt. % or 0.05 wt. %, or any range of values therebetween. In some embodiments, the steel alloy composition comprises phosphorus (P) in an amount of, of about, of at least, of at least about, of at most, or of at most about, 1 wt. %, 0.5 wt. %, 0.1 wt. %, 0.08 wt. %, 0.07 wt. %, 0.06 wt. %, 0.05 wt. %, 0.045 wt. %, 0.04 wt. %, 0.03 wt. %, 0.02 wt. %, 0.01 wt. % or 0.005 wt. %, or any range of values therebetween. In some embodiments, the steel alloy composition comprises sulfur(S) in an amount of, of about, of at least, of at least about, of at most, or of at most about, 1 wt. %, 0.5 wt. %, 0.1 wt. %, 0.08 wt. %, 0.07 wt. %, 0.06 wt. %, 0.05 wt. %, 0.045 wt. %, 0.04 wt. %, 0.03 wt. %, 0.02 wt. %, 0.01 wt. % or 0.005 wt. %, or any range of values therebetween. In some embodiments, the steel alloy composition comprises oxygen (O) in an amount of, of about, of at least, of at least about, of at most, or of at most about, 1 wt. %, 0.5 wt. %, 0.1 wt. %, 0.08 wt. %, 0.07 wt. %, 0.06 wt. %, 0.05 wt. %, 0.045 wt. %, 0.04 wt. %, 0.03 wt. %, 0.02 wt. %, 0.01 wt. % or 0.005 wt. %, or any range of values therebetween.

In some embodiments, the steel alloy compositions may be in solid, liquid, powder, filament, coating, foam, or composite form. In some embodiments, the steel alloy composition may be in powder form. In some embodiments, particles of the steel alloy composition in powder form may have a D₅₀ average size distribution of, or of about, 20 μm, 22 μm, 24 μm, 26 μm, 28 μm, 30 μm, 32 μm, 34 μm, 36 μm, 38 μm, 40 μm, 42 μm, 44 μm, 46 μm, 48 μm, 50 μm, 52 μm, 54 μm, 56 μm, 58 μm, 60 μm, 62 μm, 64 μm, 66 μm, 68 μm, 70 μm, 72 μm, 74 μm, 76 μm, 78 μm, 80 μm, 82 μm, 84 μm, 86 μm, 88 μm, 90 μm, 92 μm, 94 μm, 96 μm, 98 μm or 100 μm, or any range of values therebetween.

In some embodiments, the steel alloy includes incorporation of carbon and/or nitrogen as interstitial hardeners or at least in part for corrosion resistance and hardening properties. In some embodiments, the total interstitial hardeners are, are about, are at most, or are at most about, 1 wt. %, 0.8 wt. %, 0.5 wt. %, 0.2 wt. % 0.15 wt. %, 0.1 wt. %, 0.05 wt. % or 0.01 wt. %, or any range of values therebetween. In some embodiments, each elemental interstitial hardener or each additional element that is not recited is, is about, is at most, or is at most about, 0.8 wt. %, 0.5 wt. %, 0.2 wt. % 0.1 wt. %, 0.05 wt. %, 0.01 wt. %, 0.005 wt. % or 0.001 wt. %, or any range of values therebetween.

In some embodiments, the steel alloy composition comprises carbon (C) in an amount of, of about, of at least, of at least about, of at most, or of at most about, 0.6 wt. %, 0.59 wt. %, 0.58 wt. %, 0.57 wt. %, 0.56 wt. %, 0.55 wt. %, 0.54 wt. %, 0.53 wt. %, 0.52 wt. %, 0.51 wt. %, 0.5 wt. %, 0.49 wt. %, 0.48 wt. %, 0.47 wt. %, 0.46 wt. %, 0.45 wt. %, 0.44 wt. %, 0.43 wt. %, 0.42 wt. %, 0.41 wt. %, 0.4 wt. %, 0.39 wt. %, 0.38 wt. %, 0.37 wt. %, 0.36 wt. %, 0.35 wt. %, 0.34 wt. %, 0.33 wt. %, 0.32 wt. %, 0.31 wt. %, 0.3 wt. %, 0.29 wt. %, 0.28 wt. %, 0.27 wt. %, 0.26 wt. %, 0.25 wt. %, 0.24 wt. %, 0.23 wt. %, 0.22 wt. %, 0.21 wt. %, 0.2 wt. %, 0.19 wt. %, 0.18 wt. %, 0.17 wt. %, 0.16 wt. %, 0.15 wt. %, 0.14 wt. %, 0.13 wt. %, 0.12 wt. %, 0.11 wt. %, 0.1 wt. %, 0.05 wt. % or 0.01 wt. %, or any range of values therebetween.

In some embodiments, the steel alloy composition comprises nitrogen (N) in an amount of, of about, of at least, of at least about, of at most, or of at most about, 2 wt. %, 1.95 wt. %, 1.9 wt. %, 1.85 wt. %, 1.8 wt. %, 1.75 wt. %, 1.7 wt. %, 1.65 wt. %, 1.6 wt. %, 1.55 wt. %, 1.5 wt. %, 1.45 wt. %, 1.4 wt. %, 1.35 wt. %, 1.3 wt. %, 1.25 wt. %, 1.2 wt. %, 1.15 wt. %, 1.1 wt. %, 1.05 wt. %, 1 wt. %, 0.95 wt. %, 0.9 wt. %, 0.85 wt. %, 0.8 wt. %, 0.75 wt. %, 0.7 wt. %, 0.65 wt. %, 0.6 wt. %, 0.55 wt. %, 0.5 wt. %, 0.45 wt. %, 0.4 wt. %, 0.35 wt. %, 0.3 wt. %, 0.25 wt. %, 0.2 wt. %, 0.1 wt. %, 0.05 wt. % or 0.01 wt. % or any range of values therebetween.

In some embodiments, the steel alloy composition comprises chromium (Cr) in an amount of, of about, of at least, of at least about, of at most, or of at most about, 5.5 wt. %, 5.4 wt. %, 5.3 wt. %, 5.2 wt. %, 5.1 wt. %, 5 wt. %, 4.5 wt. %, 4 wt. %, 3.5 wt. %, 3 wt. %, 2.5 wt. %, 2 wt. %, 1.5 wt. %, 1.49 wt. %, 1.48 wt. %, 1.47 wt. %, 1.46 wt. %, 1.45 wt. %, 1.44 wt. %, 1.43 wt. %, 1.42 wt. %, 1.41 wt. %, 1.4 wt. %, 1.39 wt. %, 1.38 wt. %, 1.37 wt. %, 1.36 wt. %, 1.35 wt. %, 1.34 wt. %, 1.33 wt. %, 1.32 wt. %, 1.31 wt. %, 1.3 wt. %, 1.29 wt. %, 1.28 wt. %, 1.27 wt. %, 1.26 wt. %, 1.25 wt. %, 1.24 wt. %, 1.23 wt. %, 1.22 wt. %, 1.21 wt. %, 1.2 wt. %, 1.19 wt. %, 1.18 wt. %, 1.17 wt. %, 1.16 wt. %, 1.15 wt. %, 1.14 wt. %, 1.13 wt. %, 1.12 wt. %, 1.11 wt. %, 1.1 wt. %, 1.09 wt. %, 1.08 wt. %, 1.07 wt. %, 1.06 wt. %, 1.05 wt. %, 1.04 wt. %, 1.03 wt. %, 1.02 wt. %, 1.01 wt. %, 1 wt. %, 0.99 wt. %, 0.98 wt. %, 0.97 wt. %, 0.96 wt. %, 0.95 wt. %, 0.94 wt. %, 0.93 wt. %, 0.92 wt. %, 0.91 wt. %, 0.9 wt. %, 0.89 wt. %, 0.88 wt. %, 0.87 wt. %, 0.86 wt. %, 0.85 wt. %, 0.84 wt. %, 0.83 wt. %, 0.82 wt. %, 0.81 wt. %, 0.8 wt. %, 0.79 wt. %, 0.78 wt. %, 0.77 wt. %, 0.76 wt. %, 0.75 wt. %, 0.74 wt. %, 0.73 wt. %, 0.72 wt. %, 0.71 wt. %, 0.7 wt. %, 0.69 wt. %, 0.68 wt. %, 0.67 wt. %, 0.66 wt. %, 0.65 wt. %, 0.64 wt. %, 0.63 wt. %, 0.62 wt. %, 0.61 wt. %, 0.6 wt. %, 0.59 wt. %, 0.58 wt. %, 0.57 wt. %, 0.56 wt. %, 0.55 wt. %, 0.54 wt. %, 0.53 wt. %, 0.52 wt. %, 0.51 wt. %, 0.5 wt. %, 0.49 wt. %, 0.48 wt. %, 0.47 wt. %, 0.46 wt. %, 0.45 wt. %, 0.44 wt. %, 0.43 wt. %, 0.42 wt. %, 0.41 wt. %, 0.4 wt. %, 0.39 wt. %, 0.38 wt. %, 0.37 wt. %, 0.36 wt. %, 0.35 wt. %, 0.34 wt. %, 0.33 wt. %, 0.32 wt. %, 0.31 wt. %, 0.3 wt. %, 0.29 wt. %, 0.28 wt. %, 0.27 wt. %, 0.26 wt. %, 0.25 wt. %, 0.24 wt. %, 0.23 wt. %, 0.22 wt. %, 0.21 wt. %, 0.2 wt. %, 0.19 wt. %, 0.18 wt. %, 0.17 wt. %, 0.16 wt. %, 0.15 wt. %, 0.14 wt. %, 0.13 wt. %, 0.12 wt. %, 0.11 wt. % or 0.1 wt. %, or any range of values therebetween.

In some embodiments, the steel alloy composition comprises nickel (Ni) in an amount of, of about, of at least, of at least about, of at most, or of at most about, 6 wt. %, 5.95 wt. %, 5.9 wt. %, 5.85 wt. %, 5.8 wt. %, 5.75 wt. %, 5.7 wt. %, 5.65 wt. %, 5.6 wt. %, 5.55 wt. %, 5.5 wt. %, 5.45 wt. %, 5.4 wt. %, 5.35 wt. %, 5.3 wt. %, 5.25 wt. %, 5.2 wt. %, 5.15 wt. %, 5.1 wt. %, 5.05 wt. %, 5 wt. %, 4.95 wt. %, 4.9 wt. %, 4.85 wt. %, 4.8 wt. %, 4.75 wt. %, 4.7 wt. %, 4.65 wt. %, 4.6 wt. %, 4.55 wt. %, 4.5 wt. %, 4.45 wt. %, 4.4 wt. %, 4.35 wt. %, 4.3 wt. %, 4.25 wt. %, 4.2 wt. %, 4.15 wt. %, 4.1 wt. %, 4.05 wt. %, 4 wt. %, 3.95 wt. %, 3.9 wt. %, 3.85 wt. %, 3.8 wt. %, 3.75 wt. %, 3.7 wt. %, 3.65 wt. %, 3.6 wt. %, 3.55 wt. %, 3.5 wt. %, 3.45 wt. %, 3.4 wt. %, 3.35 wt. %, 3.3 wt. %, 3.25 wt. %, 3.2 wt. %, 3.15 wt. %, 3.1 wt. %, 3.05 wt. %, 3 wt. %, 2.95 wt. %, 2.9 wt. %, 2.85 wt. %, 2.8 wt. %, 2.75 wt. %, 2.7 wt. %, 2.65 wt. %, 2.6 wt. %, 2.55 wt. %, 2.5 wt. %, 2.45 wt. %, 2.4 wt. %, 2.35 wt. %, 2.3 wt. %, 2.25 wt. %, 2.2 wt. %, 2.15 wt. %, 2.1 wt. %, 2.05 wt. %, 2 wt. %, 1.95 wt. %, 1.9 wt. %, 1.85 wt. %, 1.8 wt. %, 1.75 wt. %, 1.7 wt. %, 1.65 wt. %, 1.6 wt. %, 1.55 wt. %, 1.5 wt. %, 1 wt. %, 0.9 wt. %, 0.8 wt. %, 0.7 wt. %, 0.6 wt. % or 0.5 wt. %, or any range of values therebetween.

In some embodiments, the steel alloy composition comprises manganese (Mn) in an amount of, of about, of at least, of at least about, of at most, or of at most about, 4.5 wt. %, 4.45 wt. %, 4.4 wt. %, 4.35 wt. %, 4.3 wt. %, 4.25 wt. %, 4.2 wt. %, 4.15 wt. %, 4.1 wt. %, 4.05 wt. %, 4 wt. %, 3.95 wt. %, 3.9 wt. %, 3.85 wt. %, 3.8 wt. %, 3.75 wt. %, 3.7 wt. %, 3.65 wt. %, 3.6 wt. %, 3.55 wt. %, 3.5 wt. %, 3.45 wt. %, 3.4 wt. %, 3.35 wt. %, 3.3 wt. %, 3.25 wt. %, 3.2 wt. %, 3.15 wt. %, 3.1 wt. %, 3.05 wt. %, 3 wt. %, 2.95 wt. %, 2.9 wt. %, 2.85 wt. %, 2.8 wt. %, 2.75 wt. %, 2.7 wt. %, 2.65 wt. %, 2.6 wt. %, 2.55 wt. %, 2.5 wt. %, 2.45 wt. %, 2.4 wt. %, 2.35 wt. %, 2.3 wt. %, 2.25 wt. %, 2.2 wt. %, 2.15 wt. %, 2.1 wt. %, 2.05 wt. %, 2 wt. %, 1.95 wt. %, 1.9 wt. %, 1.85 wt. %, 1.8 wt. %, 1.75 wt. %, 1.7 wt. %, 1.65 wt. %, 1.6 wt. %, 1.55 wt. %, 1.5 wt. %, 1.45 wt. %, 1.4 wt. %, 1.35 wt. %, 1.3 wt. %, 1.25 wt. %, 1.2 wt. %, 1.15 wt. %, 1.1 wt. %, 1.05 wt. %, 1 wt. %, 0.95 wt. %, 0.9 wt. %, 0.85 wt. %, 0.8 wt. %, 0.75 wt. %, 0.7 wt. %, 0.65 wt. %, 0.6 wt. %, 0.55 wt. %, 0.5 wt. %, 0.45 wt. %, 0.4 wt. %, 0.35 wt. %, 0.3 wt. %, 0.25 wt. %, 0.2 wt. %, 0.19 wt. %, 0.18 wt. %, 0.17 wt. %, 0.16 wt. %, 0.15 wt. %, 0.1 wt. % or 0.01 wt. %, or any range of values therebetween.

In some embodiments, the steel alloy composition comprises molybdenum (Mo) in an amount of, of about, of at least, of at least about, of at most, or of at most about, 4 wt. %, 3.9 wt. %, 3.8 wt. %, 3.7 wt. %, 3.6 wt. %, 3.5 wt. %, 3 wt. %, 2.9 wt. %, 2.8 wt. %, 2.7 wt. %, 2.6 wt. %, 2.5 wt. %, 2.4 wt. %, 2.3 wt. %, 2.2 wt. %, 2.1 wt. %, 2 wt. %, 1.9 wt. %, 1.8 wt. %, 1.7 wt. %, 1.6 wt. %, 1.5 wt. %, 1.4 wt. %, 1.3 wt. %, 1.2 wt. %, 1.1 wt. %, 1 wt. %, 0.9 wt. %, 0.8 wt. %, 0.7 wt. %, 0.6 wt. % or 0.5 wt. %, or any range of values therebetween.

In some embodiments, the steel alloy composition comprises vanadium (V) or (Va) in an amount of, of about, of at least, of at least about, of at most, or of at most about, 0.8 wt. %, 0.75 wt. %, 0.7 wt. %, 0.65 wt. %, 0.64 wt. %, 0.63 wt. %, 0.62 wt. %, 0.61 wt. %, 0.6 wt. %, 0.59 wt. %, 0.58 wt. %, 0.57 wt. %, 0.56 wt. %, 0.55 wt. %, 0.54 wt. %, 0.53 wt. %, 0.52 wt. %, 0.51 wt. %, 0.5 wt. %, 0.49 wt. %, 0.48 wt. %, 0.47 wt. %, 0.46 wt. %, 0.45 wt. %, 0.44 wt. %, 0.43 wt. %, 0.42 wt. %, 0.41 wt. %, 0.4 wt. %, 0.39 wt. %, 0.38 wt. %, 0.37 wt. %, 0.36 wt. %, 0.35 wt. %, 0.34 wt. %, 0.33 wt. %, 0.32 wt. %, 0.31 wt. %, 0.3 wt. %, 0.29 wt. %, 0.28 wt. %, 0.27 wt. %, 0.26 wt. %, 0.25 wt. %, 0.24 wt. %, 0.23 wt. %, 0.22 wt. %, 0.21 wt. %, 0.2 wt. %, 0.19 wt. %, 0.18 wt. %, 0.17 wt. %, 0.16 wt. %, 0.15 wt. %, 0.14 wt. %, 0.13 wt. %, 0.12 wt. %, 0.11 wt. %, 0.1 wt. % or 0.01 wt. %, or any range of values therebetween.

In some embodiments, the steel alloy composition comprises tungsten (W) in an amount of, of about, of at least, of at least about, of at most, or of at most about, 2.5 wt. %, 2.4 wt. %, 2.3 wt. %, 2.2 wt. %, 2.1 wt. %, 2 wt. %, 1.9 wt. %, 1.8 wt. %, 1.7 wt. %, 1.6 wt. %, 1.5 wt. %, 1.4 wt. %, 1.3 wt. %, 1.2 wt. %, 1.1 wt. %, 1 wt. %, 0.9 wt. %, 0.89 wt. %, 0.88 wt. %, 0.87 wt. %, 0.86 wt. %, 0.85 wt. %, 0.84 wt. %, 0.83 wt. %, 0.82 wt. %, 0.81 wt. %, 0.8 wt. %, 0.79 wt. %, 0.78 wt. %, 0.77 wt. %, 0.76 wt. %, 0.75 wt. %, 0.74 wt. %, 0.73 wt. %, 0.72 wt. %, 0.71 wt. %, 0.7 wt. %, 0.69 wt. %, 0.68 wt. %, 0.67 wt. %, 0.66 wt. %, 0.65 wt. %, 0.64 wt. %, 0.63 wt. %, 0.62 wt. %, 0.61 wt. %, 0.6 wt. %, 0.59 wt. %, 0.58 wt. %, 0.57 wt. %, 0.56 wt. %, 0.55 wt. %, 0.54 wt. %, 0.53 wt. %, 0.52 wt. %, 0.51 wt. %, 0.5 wt. %, 0.49 wt. %, 0.48 wt. %, 0.47 wt. %, 0.46 wt. %, 0.45 wt. %, 0.44 wt. %, 0.43 wt. %, 0.42 wt. %, 0.41 wt. %, 0.4 wt. %, 0.39 wt. %, 0.38 wt. %, 0.37 wt. %, 0.36 wt. %, 0.35 wt. %, 0.34 wt. %, 0.33 wt. %, 0.32 wt. %, 0.31 wt. %, 0.3 wt. %, 0.29 wt. %, 0.28 wt. %, 0.27 wt. %, 0.26 wt. %, 0.25 wt. %, 0.24 wt. %, 0.23 wt. %, 0.22 wt. %, 0.21 wt. %, 0.2 wt. %, 0.19 wt. %, 0.18 wt. %, 0.17 wt. %, 0.16 wt. %, 0.15 wt. %, 0.14 wt. %, 0.13 wt. %, 0.12 wt. %, 0.11 wt. %, 0.1 wt. % or 0.01 wt. %, or any range of values therebetween.

In some embodiments, the steel alloy composition comprises copper (Cu) in an amount of, of about, of at least, of at least about, of at most, or of at most about, 2.2 wt. %, 2.1 wt. %, 2 wt. %, 1.9 wt. %, 1.8 wt. %, 1.7 wt. %, 1.6 wt. %, 1.5 wt. %, 1.45 wt. %, 1.4 wt. %, 1.35 wt. %, 1.3 wt. %, 1.25 wt. %, 1.2 wt. %, 1.15 wt. %, 1.1 wt. %, 1.05 wt. %, 1 wt. %, 0.95 wt. %, 0.9 wt. %, 0.85 wt. % or 0.8 wt. %, or any range of values therebetween.

In some embodiments, the steel alloy composition comprises cobalt (Co) in an amount of, of about, of at least, of at least about, of at most, or of at most about, 6 wt. %, 5.9 wt. %, 5.8 wt. %, 5.7 wt. %, 5.6 wt. %, 5.5 wt. %, 5.4 wt. %, 5.3 wt. %, 5.2 wt. %, 5.1 wt. %, 5 wt. %, 4.9 wt. %, 4.8 wt. %, 4.7 wt. %, 4.6 wt. %, 4.5 wt. %, 4.4 wt. %, 4.3 wt. %, 4.2 wt. %, 4.1 wt. %, 4 wt. %, 3.9 wt. %, 3.8 wt. %, 3.7 wt. %, 3.6 wt. %, 3.5 wt. %, 3.4 wt. %, 3.3 wt. %, 3.2 wt. %, 3.1 wt. %, 3 wt. %, 2.9 wt. %, 2.8 wt. %, 2.7 wt. %, 2.6 wt. %, 2.5 wt. %, 2.4 wt. %, 2.3 wt. %, 2.2 wt. %, 2.1 wt. %, 2 wt. %, 1.9 wt. %, 1.8 wt. %, 1.7 wt. %, 1.6 wt. %, 1.5 wt. %, 1.4 wt. %, 1.3 wt. %, 1.2 wt. %, 1.1 wt. %, 1 wt. %, 0.9 wt. %, 0.8 wt. %, 0.7 wt. %, 0.6 wt. %, 0.5 wt. %, 0.4 wt. %, 0.3 wt. %, 0.2 wt. %, 0.1 wt. % or 0.01 wt. %, or any range of values therebetween.

In some embodiments, the steel alloy composition comprises titanium (Ti) in an amount of, of about, of at least, of at least about, of at most, or of at most about, 0.75 wt. %, 0.74 wt. %, 0.73 wt. %, 0.72 wt. %, 0.71 wt. %, 0.7 wt. %, 0.69 wt. %, 0.68 wt. %, 0.67 wt. %, 0.66 wt. %, 0.65 wt. %, 0.64 wt. %, 0.63 wt. %, 0.62 wt. %, 0.61 wt. %, 0.6 wt. %, 0.59 wt. %, 0.58 wt. %, 0.57 wt. %, 0.56 wt. %, 0.55 wt. %, 0.54 wt. %, 0.53 wt. %, 0.52 wt. %, 0.51 wt. %, 0.5 wt. %, 0.49 wt. %, 0.48 wt. %, 0.47 wt. %, 0.46 wt. %, 0.45 wt. %, 0.44 wt. %, 0.43 wt. %, 0.42 wt. %, 0.41 wt. %, 0.4 wt. %, 0.39 wt. %, 0.38 wt. %, 0.37 wt. %, 0.36 wt. %, 0.35 wt. %, 0.34 wt. %, 0.33 wt. %, 0.32 wt. %, 0.31 wt. %, 0.3 wt. %, 0.29 wt. %, 0.28 wt. %, 0.27 wt. %, 0.26 wt. %, 0.25 wt. %, 0.24 wt. %, 0.23 wt. %, 0.22 wt. %, 0.21 wt. %, 0.2 wt. %, 0.19 wt. %, 0.18 wt. %, 0.17 wt. %, 0.16 wt. %, 0.15 wt. %, 0.14 wt. %, 0.13 wt. %, 0.12 wt. %, 0.11 wt. %, 0.1 wt. % or 0.01 wt. %, or any range of values therebetween.

The compositional ranges of various steel alloy compositions (Alloy 1, Alloy 2, Alloy 3, Alloy 4 and Alloy 5) are shown below in Table 1.

TABLE 1
Alloy	Fe	C	N	Mn	Ni	Cr	V	Mo	W	Cu	Co

1	Bal.	0.05-	—	0.5-	1.5-	0.1-	0.1-	0.5-	0.01-	—	—
		0.6		4.5	4	1.5	0.6	1.2	0.9
2	Bal.	0.05-	—	3.5-	1.8-	1.1-	0.4-	1-	—	—	—
		0.6		4.5	2.2	1.3	0.6	1.2
3	Bal.	0.2-	0-	4	2	0.7-	0.3-	0.9-	—	—	—
		0.3	0.16			1.4	0.5	2.1
4	Bal.	0.2	0.04	0.5	3	0.14	0.09-	0.68-	0.65-	1.14	—
							0.23	0.85	0.82
5	Bal.	0.2-	0-	0.5	1-	3-	0.2-	1-	0.5-	0-	2
		0.3	0.08		3.5	5.4	0.6	3	1.7	2

In some embodiments, the steel alloy composition comprises martensite in an amount of, of about, of at least, of at least about, of at most, or of at most about, 100 vol. %, 95 vol. %, 90 vol. %, 85 vol. %, 80 vol. %, 70 vol. %, 60 vol. %, 50 vol. %, 40 vol. %, 30 vol. %, 25 vol. %, 20 vol. %, 18 vol. %, 16 vol. %, 15 vol. %, 14 vol. %, 13 vol. %, 12 vol. %, 11 vol. % or 10 vol. %, or any range of values therebetween.

In some embodiments, the steel alloys form martensite crystalline structures at, at about, at least, at least about, at most, or at most about, 500° C., 495° C., 490° C., 485° C., 480° C., 475° C., 470° C., 465° C., 460° C., 455° C., 450° C., 445° C., 440° C., 435° C., 430° C., 425° C., 420° C., 415° C., 410° C., 405° C., 400° C., 395° C., 390° C., 385° C., 380° C., 375° C., 370° C., 365° C., 360° C., 355° C., 350° C., 345° C., 340° C., 335° C., 330° C., 325° C., 320° C., 315° C., 310° C., 305° C., 300° C., 295° C., 290° C., 285° C., 280° C., 275° C., 270° C., 265° C., 260° C., 255° C., 250° C., 245° C., 240° C., 235° C., 230° C., 225° C., 220° C., 215° C., 210° C., 205° C., 200° C., 195° C., 190° C., 185° C., 180° C., 175° C., 170° C., 165° C., 160° C., 155° C. 150° C., 145° C., 140° C., 135° C., 130° C., 125° C., 120° C., 115° C., 110° C., 105° C., 100° C., 95° C., 90° C., 85° C., 80° C., 75° C., 70° C., 65° C., 60° C., 55° C. or 50° C., or any range of values therebetween.

In some embodiments, the steel alloys comprise a M₃C microstructure. In some embodiments, the steel alloy transitions from a M₃C microstructure to a M₂C microstructure, wherein the M₃C microstructure is an intermediate phase formed prior to the formation of the M₂C microstructure. In some embodiments, the steel alloy comprising a M₃C microstructure includes a mole fraction (f_M3C) of, of about, of at least, of at least about, of at most, or of at most about, 7.5%, 7%, 6.5%, 6%, 5.5%, 5%, 4.99%, 4.98%, 4.97%, 4.96%, 4.95%, 4.94%, 4.93%, 4.92%, 4.91%, 4.9%, 4.89%, 4.88%, 4.87%, 4.86%, 4.85%, 4.84%, 4.83%, 4.82%, 4.81%, 4.8%, 4.79%, 4.78%, 4.77%, 4.76%, 4.75%, 4.74%, 4.73%, 4.72%, 4.71%, 4.7%, 4.69%, 4.68%, 4.67%, 4.66%, 4.65%, 4.64%, 4.63%, 4.62%, 4.61%, 4.6%, 4.59%, 4.58%, 4.57%, 4.56%, 4.55%, 4.54%, 4.53%, 4.52%, 4.51%, 4.5%, 4.49%, 4.48%, 4.47%, 4.46%, 4.45%, 4.44%, 4.43%, 4.42%, 4.41%, 4.4%, 4.39%, 4.38%, 4.37%, 4.36%, 4.35%, 4.34%, 4.33%, 4.32%, 4.31%, 4.3%, 4.29%, 4.28%, 4.27%, 4.26%, 4.25%, 4.24%, 4.23%, 4.22%, 4.21%, 4.2%, 4.19%, 4.18%, 4.17%, 4.16%, 4.15%, 4.14%, 4.13%, 4.12%, 4.11%, 4.1%, 4.09%, 4.08%, 4.07%, 4.06%, 4.05%, 4.04%, 4.03%, 4.02%, 4.01%, 4%, 3.99%, 3.98%, 3.97%, 3.96%, 3.95%, 3.94%, 3.93%, 3.92%, 3.91%, 3.9%, 3.89%, 3.88%, 3.87%, 3.86%, 3.85%, 3.84%, 3.83%, 3.82%, 3.81%, 3.8%, 3.79%, 3.78%, 3.77%, 3.76%, 3.75%, 3.74%, 3.73%, 3.72%, 3.71%, 3.7%, 3.69%, 3.68%, 3.67%, 3.66%, 3.65%, 3.64%, 3.63%, 3.62%, 3.61%, 3.6%, 3.59%, 3.58%, 3.57%, 3.56%, 3.55%, 3.54%, 3.53%, 3.52%, 3.51%, 3.5%, 3.49%, 3.48%, 3.47%, 3.46%, 3.45%, 3.44%, 3.43%, 3.42%, 3.41%, 3.4%, 3.39%, 3.38%, 3.37%, 3.36%, 3.35%, 3.34%, 3.33%, 3.32%, 3.31%, 3.3%, 3.29%, 3.28%, 3.27%, 3.26%, 3.25%, 3.24%, 3.23%, 3.22%, 3.21%, 3.2%, 3.19%, 3.18%, 3.17%, 3.16%, 3.15%, 3.14%, 3.13%, 3.12%, 3.11%, 3.1%, 3.09%, 3.08%, 3.07%, 3.06%, 3.05%, 3.04%, 3.03%, 3.02%, 3.01% or 3%, or any range of values therebetween.

In some embodiments, the steel alloys comprise a M₂C microstructure. In some embodiments, the steel alloy comprising a M₂C microstructure includes a mole fraction (f_M2C) of, of about, of at least, of at least about, of at most, or of at most about, 7.5%, 7%, 6.5%, 6%, 5.5%, 5%, 4.99%, 4.98%, 4.97%, 4.96%, 4.95%, 4.94%, 4.93%, 4.92%, 4.91%, 4.9%, 4.89%, 4.88%, 4.87%, 4.86%, 4.85%, 4.84%, 4.83%, 4.82%, 4.81%, 4.8%, 4.79%, 4.78%, 4.77%, 4.76%, 4.75%, 4.74%, 4.73%, 4.72%, 4.71%, 4.7%, 4.69%, 4.68%, 4.67%, 4.66%, 4.65%, 4.64%, 4.63%, 4.62%, 4.61%, 4.6%, 4.59%, 4.58%, 4.57%, 4.56%, 4.55%, 4.54%, 4.53%, 4.52%, 4.51%, 4.5%, 4.49%, 4.48%, 4.47%, 4.46%, 4.45%, 4.44%, 4.43%, 4.42%, 4.41%, 4.4%, 4.39%, 4.38%, 4.37%, 4.36%, 4.35%, 4.34%, 4.33%, 4.32%, 4.31%, 4.3%, 4.29%, 4.28%, 4.27%, 4.26%, 4.25%, 4.24%, 4.23%, 4.22%, 4.21%, 4.2%, 4.19%, 4.18%, 4.17%, 4.16%, 4.15%, 4.14%, 4.13%, 4.12%, 4.11%, 4.1%, 4.09%, 4.08%, 4.07%, 4.06%, 4.05%, 4.04%, 4.03%, 4.02%, 4.01%, 4%, 3.99%, 3.98%, 3.97%, 3.96%, 3.95%, 3.94%, 3.93%, 3.92%, 3.91%, 3.9%, 3.89%, 3.88%, 3.87%, 3.86%, 3.85%, 3.84%, 3.83%, 3.82%, 3.81%, 3.8%, 3.79%, 3.78%, 3.77%, 3.76%, 3.75%, 3.74%, 3.73%, 3.72%, 3.71%, 3.7%, 3.69%, 3.68%, 3.67%, 3.66%, 3.65%, 3.64%, 3.63%, 3.62%, 3.61%, 3.6%, 3.59%, 3.58%, 3.57%, 3.56%, 3.55%, 3.54%, 3.53%, 3.52%, 3.51%, 3.5%, 3.49%, 3.48%, 3.47%, 3.46%, 3.45%, 3.44%, 3.43%, 3.42%, 3.41%, 3.4%, 3.39%, 3.38%, 3.37%, 3.36%, 3.35%, 3.34%, 3.33%, 3.32%, 3.31%, 3.3%, 3.29%, 3.28%, 3.27%, 3.26%, 3.25%, 3.24%, 3.23%, 3.22%, 3.21%, 3.2%, 3.19%, 3.18%, 3.17%, 3.16%, 3.15%, 3.14%, 3.13%, 3.12%, 3.11%, 3.1%, 3.09%, 3.08%, 3.07%, 3.06%, 3.05%, 3.04%, 3.03%, 3.02%, 3.01% or 3%, or any range of values therebetween.

FIG. 1 shows the impact toughness (J) and Rockwell hardness (HRC) of various commercial alloys, as well as toughness and hardness performance windows for alloys. FIG. 1 shows impact toughness and Rockwell hardnesses for commercial alloys HB7, C61, GNB200, H13, Dievar, MS1, W360 and M300, as well as target hardnesses of at least about 42 HRC or 50 HRC and a target impact toughness of at least about 40 J for alloys in the performance windows (e.g., Alloys A5/A6, Alloy C1 and Alloy C3). In some embodiments, the steel alloy compositions disclosed herein include a hardness of at least about 42 HRC or at least about 50 HRC and an impact toughness of at least about 40 J.

Hardness of an alloy may be given and/or calculated according to various scales. In some embodiments, hardness is given in the Rockwell scale (e.g. HRC). In some embodiments, hardness is given in Vickers scale (i.e. HV). In some embodiments, the steel alloy has a hardness of, of about, of at least, of at least about, of at most, or of at most about, 40 HRC, 41 HRC, 42 HRC, 43 HRC, 44 HRC, 45 HRC, 46 HRC, 47 HRC, 48 HRC, 49 HRC, 50 HRC, 51 HRC, 52 HRC, 53 HRC, 54 HRC, 55 HRC, 56 HRC, 57 HRC, 58 HRC, 59 HRC or 60 HRC, or any range of values therebetween. In some embodiments, the steel alloy has a hardness of, of about, of at least, of at least about, of at most, or of at most about, 350 HV, 355 HV, 360 HV, 365 HV, 370 HV, 375 HV, 380 HV, 385 HV, 390 HV, 395 HV, 400 HV, 405 HV, 410 HV, 415 HV, 420 HV, 425 HV, 430 HV, 435 HV, 440 HV, 445 HV, 450 HV, 455 HV, 460 HV, 465 HV, 470 HV, 475 HV, 480 HV, 485 HV, 490 HV, 495 HV, 500 HV, 505 HV, 510 HV, 515 HV, 520 HV, 525 HV, 530 HV, 535 HV, 540 HV, 545 HV, 550 HV, 555 HV, 560 HV, 565 HV, 570 HV, 575 HV, 580 HV, 585 HV, 590 HV, 595 HV, 600 HV, 605 HV, 610 HV, 615 HV, 620 HV, 625 HV, 630 HV, 635 HV, 640 HV, 645 HV, 650 HV, 655 HV, 660 HV, 665 HV, 670 HV, 675 HV, 680 HV, 685 HV, 690 HV, 695 HV, 700 HV, 705 HV, 710 HV, 715 HV, 720 HV, 725 HV, 730 HV, 735 HV, 740 HV, 745 HV or 750 HV, or any range of values therebetween.

Toughness of an alloy may be given and/or calculated according to various measurements. In some embodiments, toughness is measured in Joules (J). In some embodiments, toughness may be measured by impact toughness. In some embodiments, the alloy includes a toughness of, of about, of at least, of at least about, of at most, or of at most about, 40 J, 42 J, 44 J, 46 J, 48 J, 50 J, 52 J, 54 J, 56 J, 58 J, 60 J, 62 J, 64 J, 66 J, 68 J, 70 J, 72 J, 74 J, 76 J, 78 J, 80 J, 82 J, 84 J, 86 J, 88 J, 90 J, 92 J, 94 J, 96 J, 98 J, 100 J, 102 J, 104 J, 106 J, 108 J, 110 J, 112 J, 114 J, 116 J, 118 J or 120 J, or any range of values therebetween.

The steel alloys may have improved yield strengths, which may improve dent resistance and scratch resistance. In some embodiments, the yield strength of the steel alloy is, is at least, or is at least about, 500 MPa, 510 MPa, 520 MPa, 530 MPa, 540 MPa, 550 MPa, 560 MPa, 570 MPa, 580 MPa, 590 MPa, 600 MPa, 610 MPa, 620 MPa, 630 MPa, 640 MPa, 650 MPa, 660 MPa, 670 MPa, 680 MPa, 690 MPa, 700 MPa, 710 MPa, 720 MPa, 730 MPa, 740 MPa, 750 MPa, 760 MPa, 770 MPa, 780 MPa, 790 MPa, 800 MPa, 810 MPa, 820 MPa, 830 MPa, 840 MPa, 850 MPa, 860 MPa, 870 MPa, 880 MPa, 890 MPa, 900 MPa, 910 MPa, 920 MPa, 930 MPa, 940 MPa, 950 MPa, 960 MPa, 970 MPa, 980 MPa, 990 MPa, 1000 MPa, 1010 MPa, 1020 MPa, 1030 MPa, 1040 MPa, 1050 MPa, 1060 MPa, 1070 MPa, 1080 MPa, 1090 MPa, 1100 MPa, 1110 MPa, 1120 MPa, 1130 MPa, 1140 MPa, 1150 MPa, 1160 MPa, 1170 MPa, 1180 MPa, 1190 MPa, 1200 MPa, 1210 MPa, 1220 MPa, 1230 MPa, 1240 MPa, 1250 MPa, 1260 MPa, 1270 MPa, 1280 MPa, 1290 MPa, 1300 MPa, 1310 MPa, 1320 MPa, 1330 MPa, 1340 MPa, 1350 MPa, 1360 MPa, 1370 MPa, 1380 MPa, 1390 MPa, 1400 MPa, 1410 MPa, 1420 MPa, 1430 MPa, 1440 MPa, 1450 MPa, 1460 MPa, 1470 MPa, 1480 MPa, 1490 MPa, 1500 MPa, 1510 MPa, 1520 MPa, 1530 MPa, 1540 MPa, 1550 MPa, 1560 MPa, 1570 MPa, 1580 MPa, 1590 MPa, 1600 MPa, 1610 MPa, 1620 MPa, 1630 MPa, 1640 MPa, 1650 MPa, 1660 MPa, 1670 MPa, 1680 MPa, 1690 MPa, 1700 MPa, 1710 MPa, 1720 MPa, 1730 MPa, 1740 MPa, 1750 MPa, 1760 MPa, 1770 MPa, 1780 MPa, 1790 MPa, 1800 MPa, 1810 MPa, 1820 MPa, 1830 MPa, 1840 MPa, 1850 MPa, 1860 MPa, 1870 MPa, 1880 MPa, 1890 MPa, 1900 MPa, 1910 MPa, 1920 MPa, 1930 MPa, 1940 MPa, 1950 MPa, 1960 MPa, 1970 MPa, 1980 MPa, 1990 MPa or 2000 MPa, or any range of values therebetween.

In some embodiments, the yield strength of the steel alloy at about 450° C. is, is at least, or is at least about, 900 MPa, 910 MPa, 920 MPa, 930 MPa, 940 MPa, 950 MPa, 960 MPa, 970 MPa, 980 MPa, 990 MPa, 1000 MPa, 1010 MPa, 1020 MPa, 1030 MPa, 1040 MPa, 1050 MPa, 1060 MPa, 1070 MPa, 1080 MPa, 1090 MPa, 1100 MPa, 1110 MPa, 1120 MPa, 1130 MPa, 1140 MPa, 1150 MPa, 1160 MPa, 1170 MPa, 1180 MPa, 1190 MPa, 1200 MPa, 1210 MPa, 1220 MPa, 1230 MPa, 1240 MPa, 1250 MPa, 1260 MPa, 1270 MPa, 1280 MPa, 1290 MPa, 1300 MPa, 1310 MPa, 1320 MPa, 1330 MPa, 1340 MPa, 1350 MPa, 1360 MPa, 1370 MPa, 1380 MPa, 1390 MPa, 1400 MPa, 1410 MPa, 1420 MPa, 1430 MPa, 1440 MPa, 1450 MPa, 1460 MPa, 1470 MPa, 1480 MPa, 1490 MPa, 1500 MPa, 1510 MPa, 1520 MPa, 1530 MPa, 1540 MPa, 1550 MPa, 1560 MPa, 1570 MPa, 1580 MPa, 1590 MPa, 1600 MPa, 1610 MPa, 1620 MPa, 1630 MPa, 1640 MPa, 1650 MPa, 1660 MPa, 1670 MPa, 1680 MPa, 1690 MPa, 1700 MPa, 1710 MPa, 1720 MPa, 1730 MPa, 1740 MPa, 1750 MPa, 1760 MPa, 1770 MPa, 1780 MPa, 1790 MPa, 1800 MPa, 1810 MPa, 1820 MPa, 1830 MPa, 1840 MPa, 1850 MPa, 1860 MPa, 1870 MPa, 1880 MPa, 1890 MPa, 1900 MPa, 1910 MPa, 1920 MPa, 1930 MPa, 1940 MPa, 1950 MPa, 1960 MPa, 1970 MPa, 1980 MPa, 1990 MPa or 2000 MPa, or any range of values therebetween.

Contoured Cooling Inserts and Other Products

Steel alloy compositions described herein may be used in cooling inserts to help form a cast metal product and/or other products including but not limited to automotive components (e.g., powertrain gears and rotor shafts), consumer electronics, industrial machinery, and aerospace parts. In some embodiments, the steel composition may be formed into a product by die casting, injection molding and/or additive manufacturing. In some embodiments, the cooling inserts may be used as cooling systems, heat sinks, thermal conductive inserts, and thermal management structures within a molding apparatus to aid in the production of cast metal products. In some embodiments, the cooling insert is a contoured cooling insert.

FIG. 2A is a cross-sectional schematic illustration of a portion of a non-conformal cooling channel 200. The non-conformal cooling channel 200 includes a cooling channel 202 with a channel inlet 204 and a channel outlet 206. The cooling channel 202 is surrounded by an insert body 208 and is at varying distances 212 away from contoured molding surfaces 210A, 210B throughout the length of the cooling channel 202. As shown in FIG. 2A, the cooling channel 202 does not follow the shape of the contoured molding surfaces 210A, 210B.

FIG. 2B is a cross-sectional schematic illustration of a portion of a conformal cooling channel 215. The conformal cooling channel 215 includes a cooling channel 217 with a channel inlet 219 and a channel outlet 221. The cooling channel 217 is surrounded by an insert body 223 and is at a substantially consistent distance 227 away from contoured molding surfaces 225A, 225B. As shown in FIG. 2B, the cooling channel 217 follows the shape of the contoured molding surfaces 225A, 225B.

In some embodiments, the distance from the conformal cooling channel and the contoured molding surfaces may be different for each contoured molding surface.

FIG. 2C is a schematic illustration showing a cross-sectional view of a contoured cooling insert 230. As illustrated in FIG. 2C, a contoured cooling insert 230 includes an insert body 240, fasteners 245 positioned within the insert body 240, a conformal cooling channel 250 positioned within the insert body 240, channel inlet/outlet 255 where the conformal cooling channel 250 enters or exits the insert body 240, and a contoured molding surface 260. The conformal cooling channel 250 conforms to the contoured molding surface 260 such that the channels follow a shape of the contoured molding surface 260 at or at about a constant distance. The insert body 240 occupies a volume of the contoured cooling insert 230 excluding the fasteners 245 and conformal cooling channel 250. The conformal cooling channel 250 is conformed (e.g., curved following a shape of the contoured molding surface) to maximize cooling within the contoured molding surface 260, enhancing heat transfer.

In some embodiments, the contoured cooling insert includes 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 14, 16, 20, 25 or 30 conformal cooling channels, or any range of values therebetween. In some embodiments, each conformal cooling channel may have one or more channel inlets and/or outlets, or may share a channel inlet and/or outlet with another conformal cooling channel.

In some embodiments, the contoured cooling insert is formed by an additive manufacturing process. In some embodiments, the additive manufacturing process includes using 3-D (3-dimensional) printing processes such as laser melting, laser sintering, and jetting. In some embodiments, the 3-D printing process additively provides layers of metals in designated areas of an insert body to form contoured molding surfaces and conformal cooling channels.

In some embodiments, the contoured cooling insert may be further hardened and toughened by providing a functionally graded microstructure by carburizing, solution nitriding, carbon nitriding, and/or nitriding. In some embodiments, the steel alloy composition may be subjected to carburizing, solution nitriding, carbonitriding, and/or nitriding at a temperature of, of about, of at least, of at least about, of at most, or of at most about, 1200° C., 1195° C., 1190° C., 1185° C., 1180° C., 1175° C., 1170° C., 1165° C., 1160° C., 1155° C., 1150° C., 1145° C., 1140° C., 1135° C., 1130° C., 1125° C., 1120° C., 1115° C., 1110° C., 1105° C., 1100° C., 1095° C., 1090° C., 1085° C., 1080° C., 1075° C., 1070° C., 1065° C., 1060° C., 1055° C., 1050° C., 1045° C., 1040° C., 1035° C., 1030° C., 1025° C., 1020° C., 1015° C., 1010° C., 1005° C., 1000° C., 995° C., 990° C., 985° C., 980° C., 975° C., 970° C., 965° C., 960° C., 955° C., 950° C., 945° C., 940° C., 935° C., 930° C., 925° C., 920° C., 915° C., 910° C., 905° C., 900° C., 895° C., 890° C., 885° C., 880° C., 875° C., 870° C., 865° C., 860° C., 855° C., 850° C., 845° C., 840° C., 835° C., 830° C., 825° C., 820° C., 815° C., 810° C., 805° C., 800° C., 795° C., 790° C., 785° C., 780° C., 775° C., 770° C., 765° C., 760° C., 755° C., 750° C., 745° C., 740° C., 735° C., 730° C., 725° C., 720° C., 715° C., 710° C., 705° C., 700° C., 695° C., 690° C., 685° C., 680° C., 675° C., 670° C., 665° C., 660° C., 655° C., 650° C., 645° C., 640° C., 635° C., 630° C., 625° C., 620° C., 615° C., 610° C., 605° C., 600° C., 595° C., 590° C., 585° C., 580° C., 575° C., 570° C., 565° C., 560° C., 555° C., 550° C., 545° C., 540° C., 535° C., 530° C., 525° C., 520° C., 515° C., 510° C., 505° C., 500° C., 495° C., 490° C., 485° C., 480° C., 475° C., 470° C., 465° C., 460° C., 455° C., 450° C., 445° C., 440° C., 435° C., 430° C., 425° C., 420° C., 415° C., 410° C., 405° C. or 400° C., or any range of values therebetween.

In some embodiments, the contoured cooling insert may be subjected to aging temperatures of, of about, of at least, of at least about, of at most, or of at most about, 625° C., 620° C., 615° C., 610° C., 605° C., 600° C., 595° C., 590° C., 585° C., 580° C., 575° C., 570° C., 565° C., 560° C., 555° C., 550° C., 545° C., 540° C., 535° C., 530° C., 525° C., 520° C., 515° C., 510° C., 505° C., 500° C., 495° C., 490° C., 485° C., 480° C., 475° C., 470° C., 465° C., 460° C., 455° C., 450° C., 445° C., 440° C., 435° C., 430° C., 425° C., 420° C., 415° C., 410° C., 405° C. or 400° C., 395° C., 390° C., 385° C., 380° C., 375° C., 370° C., 365° C., 360° C., 355° C., 350° C., 345° C., 340° C., 335° C., 330° C., 325° C., 320° C., 315° C., 310° C., 305° C., 300° C., 295° C., 290° C., 285° C., 280° C., 275° C., 270° C., 265° C., 260° C., 255° C., 250° C., 245° C., 240° C., 235° C., 230° C., 225° C., 220° C., 215° C., 210° C., 205° C., 200° C., 195° C., 190° C., 185° C., 180° C., 175° C., 170° C., 165° C., 160° C., 155° C. or 150° C., or any range of values therebetween.

In some embodiments, the contoured cooling insert may be subjected to aging temperatures for, for about, for at least, for least at about, for at most, or for at most about, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, 11 hours, 12 hours, 13 hours, 14 hours, 15 hours, 16 hours, 17 hours, 18 hours, 19 hours, 20 hours, 21 hours, 22 hours, 23 hours or 24 hours, or any range of values therebetween.

Use of Contoured Cooling Inserts in Molding Apparatuses

A molding apparatus is designed and used to produce a cast metal product. Cooling inserts may be placed or positioned within the molding apparatus to aid in shaping and/or cooling the cast metal product. The cooling inserts may be secured by fasteners to ensure proper positioning during a casting process. In some embodiments, a metal is melted to form a metal melt and injected into the molding apparatus, thereby taking a shape of the mold. In some embodiments, the casting process is a die casting processes (e.g., a high pressure die casting (HPDC) process). In some embodiments, the casting process is an injection molding process. In some embodiments, the melt is cooled in the molding apparatus to form a cast metal product. In some embodiments, cooling of the metal melt is aided by the cooling insert. In some embodiments, the molding apparatus may include a contoured cooling insert.

In some embodiments, a method of forming a molding apparatus is disclosed. A contoured cooling insert may be positioned within a molding apparatus. A metal melt may be injected into the molding apparatus, wherein the injected metal melt contacts the contoured molding surface. A cooling material may then be passed through the conformal cooling channel of the contoured cooling insert. The injected metal melt may be cooled by the conformal cooling channel to form a cast metal product.

In some embodiments, the cooling material passing through the conformal cooling channel may comprise fluids, gases, or combinations thereof. In some embodiments, the fluid may be selected from the group consisting of water, glycol mixtures (e.g., ethylene, propylene), oil, coolants, liquid metals, and combinations thereof. In some embodiments, the gases may be selected from the group consisting of air, refrigerants, inert gases (e.g., nitrogen, argon, helium, krypton, xenon), and combinations thereof.

EXAMPLES

Example embodiments of the present disclosure, including processes, materials and/or resultant products, are described in the following examples.

Example 1—Steel Alloy Compositions

Target elemental compositions for Steel Alloys A, Steel Alloys B and Steel Alloys C were developed and actual compositions of the alloys were prepared, with the actual compositions shown in Tables 2, 3 and 4 herein. In Tables 2 and 3, Alloys A1 and A3, alloys show target compositions and Alloys A2, A4, A5, A6, B1 and B2 show actual compositions produced. The Steel Alloys A included an M₂X martensitic structure, and Steel Alloys B included a Cu+M₂X martensitic structure. Other actual compositions with various microstructures within the performance windows for alloys are shown in Table 4-Steel Alloys C (i.e., Alloys C1, C2 and C3).

TABLE 2
Steel Alloys A

									Ms	fM2C @
Alloy	Fe	C	N	Mn	Ni	Cr	V	Mo	[C]	500° C.

A1	Bal.	0.3	0.04	4	2	1.4	0.3	2.1	141	4.631
A2	Bal.	0.023	0.018	3.33	1.84	0.71	0.48	0.89	209	3.226
A3	Bal.	0.3	0.04	4	2	0.9	0.5	1.7	160	4.612
A4	Bal.	0.025	0.070	2.89	1.9	1.2	0.41	1.1	195	3.24
A5	Bal.	0.035	0.076	3.16	1.92	1.31	0.54	1.21	195	3.24
A6	Bal.	0.032	0.037	2.69	1.92	1.24	0.47	1.07	195	3.24

TABLE 3
Steel Alloys B

											Ms
Alloy	Fe	C	N	Mn	Ni	Cr	V	Mo	W	Cu	[C]

B1	Bal.	0.0025	0.0023	0.07	3	0.14	0.21	0.66	0.61	1.17	404
B2	Bal.	0.0056	0.0031	0.35	2.87	0.14	0.08	0.84	0.78	1.15	397

TABLE 4
Steel Alloys C

Alloy	Fe	C	Cr	Ni	Mn	Mo	V	W	Cu	Co

C1	Bal.	0.2	3	3.5	0.5	1	0.4	1.6	—	2
C2	Bal.	0.22	—	1	0.5	2.7	0.2	0.6	2	—
C3	Bal.	0.26	5.34	1	0.5	2.3	0.6	—	—	—

Example 2—Characterization of Steel Alloy Compositions

FIGS. 3A-5 shows computational results of Steel Alloy A6.

FIG. 6 is a graph showing results of a Vickers hardness profile of Steel Alloy A6 based on depth distances of the alloy surface. As shown in FIG. 6, Steel Alloy A6, even at depth distances of 3 mm, the Steel Alloy A6 surprisingly and advantageously demonstrated stable Vickers hardness values above about 300 HV.

FIG. 7A is a graph showing results of a Rockwell hardness profile of a carburized Steel Alloy A6 over aging time, according to some embodiments. As shown in FIG. 7A, even after 10 hours of aging time and at various distances from the molding surface (i.e., about 0.25 mm and about 0.75 mm from the surface), the Steel Alloy A6 at both aging temperatures of 510° C. and 575° C. showed stable HRC values above about 40 HRC.

FIG. 7B is a graph showing results of a Rockwell hardness profile of another carburized Steel Alloy B1 over aging time, according to some embodiments. As shown in FIG. 7B, even after 10 hours of aging time and at various distances from the molding surface (i.e., about 0.25 mm and about 0.75 mm from the surface), the Steel Alloy B1 at an aging temperature of 450° C. showed stable HRC values above about 40 HRC.

FIG. 7C is a graph showing results of a Rockwell hardness profile of the carburized steel alloy compositions of FIGS. 7A and 7B compared with commercial alloys over aging time, according to some embodiments. As shown in FIG. 7C, compared to Dievar and MS1 commercial alloys, Steel Alloys A6 and B1 showed high hardness values (e.g., above about 50 HRC) even after 10 hours of aging at 575° C. temperature.

FIG. 8A is a graph showing results of a Rockwell hardness profile of another carburized Steel Alloy C1 over aging time. As shown in FIG. 8A, even after 10 hours of aging time and at various distances from the molding surface (i.e., from the core and from the surface), the Steel Alloy C1 at an aging temperature of 575° C. showed stable HRC values above about 45 HRC.

FIG. 8B is a graph showing results of Rockwell hardness profiles of various carburized steel alloy compositions. In FIG. 8B, Steel Alloys A6, C1 and C3 showed high hardness values, e.g., above about 40 HRC at 10 hours and above about 30 HRC at 100 hours of aging at 600° C. temperature.

While certain embodiments of the inventions have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the disclosure. Indeed, the novel methods and systems described herein may be embodied in a variety of other forms. Furthermore, various omissions, substitutions and changes in the systems and methods described herein may be made without departing from the spirit of the disclosure. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the disclosure. Accordingly, the scope of the present inventions is defined only by reference to the appended claims.

Features, materials, characteristics, or groups described in conjunction with a particular aspect, embodiment, or example are to be understood to be applicable to any other aspect, embodiment or example described in this section or elsewhere in this specification unless incompatible therewith. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive. The protection is not restricted to the details of any foregoing embodiments. The protection extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Furthermore, certain features that are described in this disclosure in the context of separate implementations can also be implemented in combination in a single implementation. Conversely, various features that are described in the context of a single implementation can also be implemented in multiple implementations separately or in any suitable subcombination. Moreover, although features may be described above as acting in certain combinations, one or more features from a claimed combination can, in some cases, be excised from the combination, and the combination may be claimed as a subcombination or variation of a subcombination.

Moreover, while operations may be depicted in the drawings or described in the specification in a particular order, such operations need not be performed in the particular order shown or in sequential order, or that all operations be performed, to achieve desirable results. Other operations that are not depicted or described can be incorporated in the example methods and processes. For example, one or more additional operations can be performed before, after, simultaneously, or between any of the described operations. Further, the operations may be rearranged or reordered in other implementations. Those skilled in the art will appreciate that in some embodiments, the actual steps taken in the processes illustrated and/or disclosed may differ from those shown in the figures. Depending on the embodiment, certain of the steps described above may be removed, others may be added. Furthermore, the features and attributes of the specific embodiments disclosed above may be combined in different ways to form additional embodiments, all of which fall within the scope of the present disclosure. Also, the separation of various system components in the implementations described above should not be understood as requiring such separation in all implementations, and it should be understood that the described components and systems can generally be integrated together in a single product or packaged into multiple products. For example, any of the components for an energy storage system described herein can be provided separately, or integrated together (e.g., packaged together, or attached together) to form an energy storage system.

For purposes of this disclosure, certain aspects, advantages, and novel features are described herein. Not necessarily all such advantages may be achieved in accordance with any particular embodiment. Thus, for example, those skilled in the art will recognize that the disclosure may be embodied or carried out in a manner that achieves one advantage or a group of advantages as taught herein without necessarily achieving other advantages as may be taught or suggested herein.

Conditional language, such as “can,” “could,” “might,” or “may,” unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain embodiments include, while other embodiments do not include, certain features, elements, and/or steps. Thus, such conditional language is not generally intended to imply that features, elements, and/or steps are in any way required for one or more embodiments or that one or more embodiments necessarily include logic for deciding, with or without user input or prompting, whether these features, elements, and/or steps are included or are to be performed in any particular embodiment.

Conjunctive language such as the phrase “at least one of X, Y, and Z,” unless specifically stated otherwise, is otherwise understood with the context as used in general to convey that an item, term, etc. may be either X, Y, or Z. Thus, such conjunctive language is not generally intended to imply that certain embodiments require the presence of at least one of X, at least one of Y, and at least one of Z.

Language of degree used herein, such as the terms “approximately,” “about,” “generally,” and “substantially” as used herein represent a value, amount, or characteristic close to the stated value, amount, or characteristic that still performs a desired function or achieves a desired result. For example, the terms “approximately”, “about”, “generally,” and “substantially” may refer to an amount that is within less than 10% of, within less than 5% of, within less than 1% of, within less than 0.1% of, and within less than 0.01% of the stated amount, depending on the desired function or desired result.

The scope of the present disclosure is not intended to be limited by the specific disclosures of preferred embodiments in this section or elsewhere in this specification, and may be defined by claims as presented in this section or elsewhere in this specification or as presented in the future. The language of the claims is to be interpreted broadly based on the language employed in the claims and not limited to the examples described in the present specification or during the prosecution of the application, which examples are to be construed as non-exclusive.