METHOD

CROSS-REFERENCE TO RELATED APPLICATION

[0001] The present application claims priority to, and the benefit of the filing date of, U.S. Provisional Patent Application Ser. No. 63/120,953 filed on December 3, 2020, which is incorporated herein by reference in its entirety for all purposes.

FIELD OF THE INVENTION

[0002] The field of the invention relates to alloys used to make components of internal combustion engines, methods for manufacturing such components, and engine components made using such alloys and methods.

BACKGROUND

[0003] There are needs for improved alloys and methods of using them to make components of internal combustion engines that resist high temperature conditions and resist oxidation in conditions of use of the components. Austenitic alloys providing elevated temperature oxidation resistance have higher costs due to nickel content, and are not generally as resistant to cyclic oxidation. Cr-Fe ferritics are prone to issues with embrittlement by intermetallics at intermediate temperatures. Nickel base alloys (employed in order to get lower CTE values) are more expensive. There is currently no SLS or similar process for direct deposition of a ferritic material with "ordinary steel" or "ordinary cast iron" properties. SUMMARY

[0004] Embodiments disclosed herein include improved ferritic alloys that comprise aluminum and silicon in combinations that provide a ferritic thermal expansion coefficient with improved high temperature oxidation resistance and cast iron-like properties without cold cracking. In embodiments, the alloy may be used in low heat input additive manufacturing processes. In embodiments, an additive alloy is provided based on Fe-Si-Al with minor alloy additions (~1% of Mn, Ti, Zr, Mo, Cr, Ni, Mg, and others ) for use in engine components exposed to elevated temperature conditions, including such components as exhaust manifolds and turbocharger housings. Embodiments disclosed herein provide improved low heat input additive manufacturing processes using such ferritic alloys to manufacture components providing improved features, enhancing benefits of the high cooling rates of additive manufacturing to optimize use of selected alloys in engine components exposed to high temperature conditions in operation. Embodiments employ advantages of microstructure variances associated with solidification conditions, optimizing characteristics based on metallic microstructure being sensitive to solidification rate, and based on the fact that material properties may be improved with reduced length scale.

[0005] This summary is provided to introduce a selection of concepts that are further described below in the illustrative embodiments. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter. Further embodiments, forms, objects, features, advantages, aspects, and benefits shall become apparent from the following description and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0006] FIG. 1 is a light photomicrograph showing a cross-sectional view of a first button formed of a first specimen alloy.

[0007] FIG. 2 is a photomicrograph of showing a cross-sectional view of the button of FIG. 1, after nital etching. [0008] FIG. 3 is a photomicrograph showing another cross-sectional view of the button of FIG. 1, after ni tai etching.

[0009] FIG. 4 is a photomicrograph showing a higher-magnification cross-sectional view of a portion of the button of FIG. 3.

[00010] FIG. 5 is a photomicrograph showing another higher-magnification cross- sectional view of a portion of the button of FIG. 3.

[00011] FIG. 6 is a photomicrograph showing a cross-sectional view of a portion of the button of FIG. 3, with hardness values measured at the marked positions.

[00012] FIG. 7 is a photomicrograph showing a surface view of a second button formed of a second specimen alloy, showing laser marks formed on the top surface of the button.

[00013] FIG. 8 is a photomicrograph showing a higher-magnification view of a portion of the button surface of FIG. 7.

[00014] FIG. 9 is a photomicrograph showing another higher-magnification view of a portion of the button surface of FIG. 7.

[00015] FIG. 10 is a photomicrograph showing a view of the top surface of the button of FIG. 7.

[00016] FIG. 11 is a photomicrograph showing a cross-sectional view, taken along a line shown in the inset, of a portion of the button of FIG. 7 in a polished state.

[00017] FIG. 12 is a photomicrograph showing a cross-sectional view, taken along a line shown in the inset, of a portion of the button of FIG. 7 after nital etching.

[00018] FIG. 13 is a photomicrograph showing a higher-magnification cross-sectional view of a portion of the button of FIG. 7 after nital etching.

[00019] FIG. 14 is a photomicrograph showing a portion of the button of FIG. 7 after nital etching.

[00020] FIG. 15 is a photomicrograph showing a portion of the button of FIG. 7, after nital etching, with hardness values measured at the marked positions. [00021] FIG. 16 is a photomicrograph showing another portion of the button of FIG. 7, after nital etching.

[00022] FIG. 17 is a photomicrograph showing a bottom view of the button of FIG. 7.

[00023] FIG. 18 is a photomicrograph showing a higher-magnification view of a portion of the bottom view of FIG. 17.

[00024] FIGS. 19A, 19B, and 19C are Fe-Al-Si phase diagrams with notations related to the alloy.

DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

[00025] Among the improved alloys of disclosed herein are the examples of alloys of Table A. The values shown in Table A represent the respective amounts of the recited starting materials, namely elements Fe, Mn, Si, and Al, used to produce specimens 1 through 11 identified in Table A (at% = atomic percentage; wt% = weight percent; g/20g = grams per 20 grams). Three specimens, namely specimens 1, 10, and 11, were produced using the same amounts of the recited starting materials.

TABLE A [00026] The preparation of starting materials may include preparation of the starting materials in the form of powders by known preparation methods such as pulverization, atomization, melt spinning, and the like to yield powder particles of appropriate particle size and particle shape. The preparation of the powder may include measuring powders of each of the alloy components in the proportions reflected in Table A.

[00027] The measured powders may be combined and then subjected to additive manufacturing procedures to yield the alloy materials. In an embodiment, the combined powders may be formed into a structure by additive manufacturing steps, such as selective laser sintering (SLS) or binder jet powder sintering.

[00028] In test examples, measured components corresponding to each of the specimen compositions recited in Table A were combined and then were arc melted to form alloy materials. The alloy materials of each specimen were formed into sample buttons of roughly circular button-like shape and cooled. After formation and cooling, the upper surfaces of the buttons were subjected to a laser treatment. In a test example, a button formed of an alloy corresponding to specimen 1 of Table A had its upper surface laser treated using an ordinary marking laser. In another test example, a button formed of an alloy corresponding to specimen 11 of Table A had its upper surface laser treated in an SLS printer. After laser treatment, the exemplary buttons were cut into two parts, roughly into halves. In each button, the cut was made in a vertical plane generally corresponding to a diameter of the circular shape of the button, extending between the upper surface and the lower surface (see position of cross-sectional view line in FIG. 11). The cut surface thus exposed internal microstructure of the button for metallographic review. Metallographic review of the base material and the material remelted by the laser treatment was conducted to reveal improved characteristics for high temperature applications of the specimen alloys in engine components. Review included inspection of microstructure of the buttons revealed in light (optical) photomicrographs and in hardness testing.

[00029] FIG. 1 is a light photomicrograph showing a cross sectional view of an exemplary first button formed of a first specimen alloy, namely, specimen 11 as identified in Table A. The photomicrograph shows a magnified view of a portion of the cut surface, revealing a cross section of the button formed of specimen 11 alloy material. The inset photo in the upper right of FIG. 1 shows a full image of the cut surface of the button, surrounded by the mounting material (lighter gray background). The arrow indicates approximately the portion of the cut surface shown in the magnified view. The image of the magnified view was taken after initial polishing of the cut surface. FIG. 1 shows that SLS cycled fusion zones appearing just below the mounting material (lighter gray mottled area at top). The SLS cycled fusion zones appear to be free of cracking.

[00030] FIG. 2 is a photomicrograph showing a cross-sectional view of the button of FIG. 1 (specimen 11), after nital etching of the cut surface. Nital etching was conducted to reveal the internal crystalline microstructure shown in FIG. 2. Due to high resistance to chemical erosion exhibited by the specimen 11 alloy, typical nital etching solution of 2% strength lacked sufficient strength to reveal sufficient microstructural features, and so 5% strength nital etching solution was used. The smaller inset photo in the upper right of FIG. 2 shows a full image of the cut surface of the button, surrounded by the mounting material (lighter gray background). The arrow approximately indicates the portion of the cut surface shown in the magnified view of FIG. 2. The magnified view shows grain boundaries (white lines) in the basic structure of the body of the button. The photomicrograph shows white lines defining boundary pass areas and fill pass areas in the SLS cycled fusion zones resulting from the SLS treatment on the surface of the button. The view shows that that the SLS cycled fusion zones appear free of cracking.

[00031] FIG. 3 is a photomicrograph showing another cross-sectional view of a portion of the button of FIG. 1 (specimen 11), after nital etching. The inset photo in the upper right of FIG. 3 shows a full image of the cut surface of the button, surrounded by the mounting material (lighter gray background). The arrow indicates approximately the portion of the cut surface shown in the magnified view of FIG. 3. The magnified photomicrograph of FIG. 3 shows another view of the microstructure of the button. Black lines show the outlines of grains, and outlines of boundary pass areas (from deeper bounding passes) and fill passes areas (shallower fill areas from fill passes) resulting from SLS treatment. The view shows that that the SLS cycled fusion zones appear free of cracking.

[00032] FIG. 4 is a photomicrograph showing a higher-magnification cross-sectional view of a portion of the button of FIG. 3 (specimen 11). The top inset photo in the upper right of FIG. 4 shows a full image of the cut surface of the button, surrounded by the mounting material (lighter gray background). The white arrow indicates approximately the portion of the cut surface shown in the lower inset photo, which is similar to FIG. 3. The black arrow indicates approximately the portion of the cut surface shown in the magnified photomicrograph of FIG. 4. The magnified view of FIG. 4 shows another view of the microstructure of the button. The photomicrograph shows a detail view of fill pass areas (marked “fill”) and a boundary pass area (marked “edge”). The view shows that that the SLS cycled fusion zones appear free of cracking.

[00033] FIG. 5 is a photomicrograph showing another higher-magnification cross- sectional view of a portion of the button of FIG. 3 (specimen 11). The top inset photo in the upper right of FIG. 5 shows a full image of the cut surface of the button, surrounded by the mounting material (lighter gray background). The white arrow indicates approximately the portion of the cut surface shown in the lower inset photo, which is similar to FIG. 3. The black arrow indicates approximately the portion of the cut surface shown in the magnified photomicrograph of FIG. 5. The large magnified photomicrograph of FIG. 5 shows a detail view of a fill pass area (marked “fill”) and a boundary pass area (marked “edge”). The view shows that that the SLS cycled fusion zones appear free of cracking. A zone of porosity is shown (large round dark area) in a lower part of the boundary pass area.

[00034] FIG. 6 is a photomicrograph showing a view of a portion of the button of FIG. 3 (specimen 11), marked with hardness values. Hardness was measured at the six marked indent positions. Indents were made at these positions at a load of HV500gf. At the marked positions as shown in the large view of FIG. 6, six measured hardness values (Vickers hardness, HV) were 240 HV, 233 HV, 247 HV, 230 HV, 235 HV, and 227 HV. A hardness value of 240 HV was measured inside a first boundary pass area. Hardness values of 233 HV and 247 HV were measured inside a second boundary pass area. Thus, the view shows that the SLS cycled fusion zones exhibit favorable high hardness values compared to the hardness values of 230 HV, 235 HV, and 227 HV that were found in the base material. It is noted that some of the indents were made at positions that were too close to one another, or to the outer surface, to comply with ASTM standards. Hardness values measured at such non-compliant positions normally would be expected to be lower, due to increased tendency of the tested material to deform, due to proximity to the neighboring indent or to the surface. However, the measured values (240 HV, 247 HV, 233 HV) in the boundary pass areas, even though measured from indents that likely were non-compliant under measurement standards, still were high compared to the measured values in the base material areas. This indicates the alloy of specimen 11 exhibits favorable high hardness levels, even within zones that were impacted by the SLS treatment.

[00035] FIG. 7 is a photomicrograph showing a surface view of a portion of a button formed of an exemplary second specimen alloy, namely, specimen 1 as identified in Table A. The photomicrograph shows laser marks made on the button formed of specimen 1 alloy, after laser passes were made on the button surface using an ordinary marking laser.

[00036] FIG. 8 is a photomicrograph showing a higher-magnification view of a portion of the button surface of FIG. 7 (specimen 1). The photomicrograph shows details of a portion of the button surface after lasers passes were made on the button surface using an ordinary marking laser.

[00037] FIG. 9 is a photomicrograph showing another higher-magnification view of a portion of the button surface of FIG. 7 (specimen 1). The photomicrograph is a higher- magnification view showing details of a portion of the button surface of FIG. 8.

[00038] FIG. 10 is a photomicrograph showing a lower-magnification view of the top surface of the button of FIG. 7 (specimen 1). The photomicrograph shows the laser marks formed on the button surface after laser passes made using a marking laser.

[00039] After laser treatment, the button formed of specimen 1 alloy was cut into two parts, roughly halves, similarly to the cut along a diameter line that was performed on the specimen 11 button as described above. FIG. 11 is a photomicrograph showing a cross- sectional view of a portion of the specimen 1 button at the cut surface, taken along a line shown in the inset of FIG. 11. FIG. 11 shows the button microstructure in an as-polished state, and reveals that the structure is free of cracks in the region of the laser remelts, namely the ridged region just below the black mounting material.

[00040] FIG. 12 is a photomicrograph showing a cross-sectional view, taken approximately along a line shown in the inset of FIG. 12, of a portion of the button of FIG. 7 (specimen 1). The image of FIG. 12 was taken after 5 % nital etching was conducted on the cut surface in order to reveal microstructural features. FIG. 12 shows the structure is free of cracks in the region of the laser remelts (ridged region just below the black mounting material). [00041] FIG. 13 is a photomicrograph showing a higher-magnification cross-sectional view of a portion of the surface of the button of FIGS. 7 and 12 (specimen 1). The image was taken after nital etching, and shows a portion of the button of FIG. 7 taken in a cross- sectional view approximately along the line shown in the upper inset photo in FIG. 13. The magnified image in the center of FIG. 13 shows the structure is free of cracks in the region of the laser remelts (ridged region just below the black mounting material). The lower inset photo in FIG. 13 is similar to FIG. 12.

[00042] FIG. 14 is a photomicrograph showing the cut surface of the button of FIG. 7 (specimen 1) after 5 % nital etching, surrounded by mounting material shown outside the white outline of the button edge. The photomicrograph shows a cross-sectional view taken approximately along the line shown in the upper inset photo in FIG. 13. The photomicrograph reveals internal microstructure, showing favorable characteristics of the sample of the specimen 1 allow. The view shows large grain size and an aligned grain orientation, both of which may be favorable characteristics of the alloy for use in high- temperature applications such as forming components of internal combustion engines.

[00043] FIG. 15 is a photomicrograph showing a portion of the button of FIG. 7 (specimen 1) in a cross-sectional view taken approximately along the line identified in the upper inset in FIG. 15. The magnified image was taken after 5% nital etching, and after indents were made to measure hardness. The view shows microstructure and includes hardness values (Vickers hardness, HV) that were measured at the five marked indent positions. Marked indent positions were made in the basic material zones of the button, in contrast to remelt zones along the surface areas, which were impacted by the laser treatment. At the marked positions as shown in FIG. 15, the measured hardness values were 231 HV, 235 HV, 232 HV, 228 HV, and 232 HV. The estimated UTS value, based on ISO 18265 conversion was 230 HV -> ~ 740 MPa UTS. The magnified illustration of FIG. 15 shows that the HV500gf hardness indents are large relative to those indents that had been made in the remelt features in FIG. 6. For example, as seen in FIG. 6, a hardness value of 240 HV was measured inside a first laser boundary pass area. Hardness values of 233 HV and 247 HV were measured inside a second laser boundary pass area. This comparison indicates the alloy of specimen 1 exhibits favorable high hardness levels, even within zones that were impacted by a marking laser treatment. As shown in FIG. 15, he small remelts do not show structural difference from the bulk casting. [00044] FIG. 16 is a photomicrograph showing another portion of the cut button surface of FIG. 7, after nital etching. The photomicrograph shows microstructure at a position approximately indicated in the lower inset photograph in FIG. 16. The large magnified view of FIG. 16 shows a cross-sectional view taken approximately along the line shown in the upper inset photo in FIG. 16. Macro solidification pattern of the button shows some shrinkage porosity. Some shrinkage porosity sites are labelled in the magnified view of FIG. 16.

[00045] FIG. 17 is a photomicrograph showing a bottom view of the button of FIG. 7, formed of the specimen 1 alloy.

[00046] FIG. 18 is a photomicrograph showing a higher-magnification view of a portion of the bottom side view of the button depicted in FIG. 17 (specimen 1), taken approximately at a position indicated in the inset photo in the upper right side of FIG. 18. The views of FIGS. 17 and 18 show cracking at conventional weld heat input positions on the bottom side of the button. The bottom side of the button was not subjected to laser treatment. The cracking at the conventional welding zone is in contrast to the lack of cracking seen in the laser-treated zones on the top side of the button (see FIGS. 11-13). The comparison tends to show the favorable characteristic of tolerance for laser treatment without cracking, as exhibited by the specimen 1 alloy.

[00047] FIGS. 19A, 19B, 19C are Fe-Al-Si phase diagrams (source: ASM Handbooks Online, ASM Alloy Phase Diagram Database) with added notations showing determinations disclosed herein regarding ferritic single phase alloys from room temperature to above 1000 °C for alloys with content of ~5 Al and 5 Si. These figures show ternary phase diagrams with the disclosed determinations (indicated by the small circle areas positioned near the tops of each of the three diagrams), of the approximate composition limits of the base portions of the claimed alloys (Fe, Si, Al). The small circle areas indicate, for each of the three isothermal sections, that the material/matrix of the disclosed alloys will be single phase ferrite from low temperature up to a very high temperature (near melting, and above the expected temperature in a condition of use of an engine component).

[00048] At a low carbon content (< 0.030 to 0.040 weight percent), the material according to embodiments disclosed herein will provide good weldability characteristics, in terms of resistance to formation of brittle martensite. [00049] The material according to embodiments disclosed herein can accommodate significant additions of other elements to further increase high temperature properties. Examples include: ~1% of Ti, Zr, Mo, Cr, Ni, Mg; catalytic additions exemplified by Pt, Ir, Re, Ti, Pd; and the iron aluminosilicate (garnet) scale. SLS techniques for grain orientation control in FeSi transformer core steels are to be employed in an embodiment of the process disclosed herein.

[00050] The low-cost compositions embodied by the alloy disclosed herein will provide the favorable mechanical properties of ordinary cast iron in an alloy optimized for use in additive manufacturing. In an embodiment, the alloy has extra low carbon content (< 0.04 weight %) to avoid formation of austenite and hard austenite transformation products. In an embodiment, the alloy has a small Mn addition (~ 0.3 - ~ 0.6%) to minimize potential for sulfur driven hot cracking. In an embodiment, the alloy has low phosphorus and sulfur contents (> 0.040%) to avoid related issues.

[00051] In embodiments disclosed herein, the alloy has good weldability in terms of freedom from cold cracking from hard/brittle microstructures. In some embodiments, techniques are employed for grain size and grain orientation control. The techniques may be preferably employed in additive manufacture applications of the alloy, in a manner related to techniques used for silicon iron relay steels. In embodiments disclosed herein, additive manufacture of the material (i. e. , by SLS) provides smaller imperfections than those resulting from conventional casting, along with Hall-Petch strengthening related to small grain sizes resulting from manufacture in accord with embodiments of the process disclosed herein.

[00052] In embodiments disclosed herein, the disclosed alloy has desirable properties exceeding those of ordinary cast irons, and approaching those of the ductile cast iron used in exhaust manifolds, in terms of both favorable room temperature mechanical properties and cyclic oxidation resistance. In embodiments disclosed herein, the oxidation scale is an adherent iron aluminosilicate (garnet) type scale. An addition of Mo preferably is used, in an embodiment, to provide a material with the favorable elevated-temperature mechanical properties of SiMo ductile iron exhaust manifold material.

[00053] In an embodiment, Cr is excluded from the alloy composition. In an embodiment, with the absence of Cr in the material forming the alloy, the material being free of Cr may provide beneficial features in elevated temperature fuel cell applications where Cr vaporization may be detrimental to desired functionality.

[00054] According to an embodiment disclosed herein, the disclosed material is optimized so as to avoid detrimental formation of embrittling phases at intermediate temperatures. In embodiments, additions of up to ~1% of several other alloying elements (examples: Ti, Zr, Mo, Cr, Ni, Mg, Pt, Ir, Re, Pd, Ag, Au) preferably are made, with the effect of improving mechanical strength and/or surface catalytic properties without destabilizing the ferritic structure. Catalytic additions preferably are made in some embodiments to provide fouling resistance benefits. The composition of the material according to embodiments disclosed herein displays reasonable steam oxidation response similar to currently-employed SiMo exhaust manifold material for fretting resistance at slip joints.

[00055] Various aspects of the present disclosure are contemplated as indicated in the claims appended hereto. All possible sub-combinations of the following embodiments are contemplated.

[00056] According to one aspect of embodiments disclosed herein, a heat-resistant ferritic alloy material comprises Fe and, by weight percent, Al: ~ 2% to ~ 6%; Si: ~ 2% to ~ 6%; Mn: ~ 0.3 to ~ 1.1%; C: 0.05% or less; P: 0.040% or less; and S: 0.040% or less. In an embodiment, the alloy material further comprises, by weight percent, ~ 1% or less of at least one of: Ti, Zr, Mo, Cr, Ni, Mg, Pt, Pd, Re, Au, Ag, Cu, Ir, Ru, Ce, Li, Na, K, Hf, and Rh. In an embodiment, the at least one of: Ti, Zr, Mo, Cr, Ni, Mg, Pt, Pd, Re, Au, Ag, Cu, Ir, Ru, Ce, Li, Na, K, Hf, and Rh increases resistance of the material to high temperatures. In an embodiment, the at least one of: Ti, Zr, Mo, Cr, Ni, Mg, Pt, Pd, Re, Au, Ag, Cu, Ir, Ru, Ce, Li, Na, K, Hf, and Rh forms at least one of a dispersion of oxide, nitride, and second phase particles in a ferrite matrix of the material. In an embodiment, the at least one of: Ti, Zr, Mo, Cr, Ni, Mg, Pt, Pd, Re, Au, Ag, Cu, Ir, Ru, Ce, Li, Na, K, Hf, and Rh increases catalytic properties of the material.

[00057] According to an embodiment disclosed herein, a heat-resistant ferritic alloy material comprises Fe and, by weight percent, Al: ~ 2% to ~ 6%; Si: ~ 2% to ~ 6%; Mn: ~ 0.3 to ~ 1.1%; C: 0.05% or less; P: 0.040% or less; and S: 0.040% or less, and the weight percent of Al is ~ 1.5% to ~ 3.5%. In another embodiment, the weight percent of Si is ~ 1.5% to ~ 3.5%. In an embodiment, the weight percent of Al is ~ 1.5% to ~ 3.5% and of Si is ~ 1.5% to ~ 3.5%. In an embodiment, the weight percent of C is 0.04% or less.

[00058] According to an embodiment disclosed herein, a heat-resistant ferritic alloy material comprises Fe and, by weight percent, Al: ~ 2% to ~ 6%; Si: ~ 2% to ~ 6%; Mn: ~ 0.3 to ~ 1.1%; C: 0.05% or less; P: 0.040% or less; and S: 0.040% or less, and the weight percent of Al is ~ 1.5% to ~ 3.5%, and the material forms an adherent ferroaluminosilicate oxide film. In an embodiment, the ferroaluminosilicate oxide film provides resistance to at least one of: high temperature oxidation, cyclic oxidation scaling, erosion, carburization, and coking.

[00059] According to an embodiment disclosed herein, a heat-resistant ferritic alloy material consists essentially of: Fe, and, by weight percent, Al: ~ 2% to ~ 6%; Si: ~ 2% to ~ 6%; Mn: ~ 0.3 to ~ 1.1%; C: 0.05% or less; P: 0.040% or less; and S: 0.040% or less. In an embodiment, the allow material may further comprise, by weight percent, ~ 1% or less of at least one of: Ti, Zr, Mo, Cr, Ni, Mg, Pt, Pd, Re, Au, Ag, Cu, Ir, Ru, Ce, Li, Na, K, Hf, and Rh. In an embodiment, the at least one of: Ti, Zr, Mo, Cr, Ni, Mg, Pt, Pd, Re, Au, Ag, Cu, Ir, Ru, Ce, Li, Na, K, Hf, and Rh increases resistance of the material to high temperatures. In an embodiment, the at least one of: Ti, Zr, Mo, Cr, Ni, Mg, Pt, Pd, Re, Au, Ag, Cu, Ir, Ru, Ce, Li, Na, K, Hf, and Rh forms at least one of a dispersion of oxide, nitride, and second phase particles in a ferrite matrix of the material. In an embodiment, the at least one of: Ti, Zr, Mo, Cr, Ni, Mg, Pt, Pd, Re, Au, Ag, Cu, Ir, Ru, Ce, Li, Na, K, Hf, and Rh increases catalytic properties of the material.

[00060] In an embodiment, a heat-resistant ferritic alloy material consists essentially of: Fe, and, by weight percent, Al: ~ 2% to ~ 6%; Si: ~ 2% to ~ 6%; Mn: ~ 0.3 to ~ 1.1%; C: 0.05% or less; P: 0.040% or less; and S: 0.040% or less, and the weight percent of Al is ~ 1.5% to - 3.5%.

[00061] In an embodiment, a heat-resistant ferritic alloy material consists essentially of: Fe, and, by weight percent, Al: - 2% to - 6%; Si: - 2% to - 6%; Mn: - 0.3 to - 1.1%; C: 0.05% or less; P: 0.040% or less; and S: 0.040% or less, and the weight percent of Si is - 1.5% to - 3.5%.

[00062] In an embodiment, a heat-resistant ferritic alloy material consists essentially of: Fe, and, by weight percent, Al: - 2% to - 6%; Si: - 2% to - 6%; Mn: - 0.3 to - 1.1%; C: 0.05% or less; P: 0.040% or less; and S: 0.040% or less, and the weight percent of Al is ~ 1.5% to ~ 3.5% and of Si is ~ 1.5% to ~ 3.5%.

[00063] In an embodiment, a heat-resistant ferritic alloy material consists essentially of: Fe, and, by weight percent, Al: ~ 2% to ~ 6%; Si: ~ 2% to ~ 6%; Mn: ~ 0.3 to ~ 1.1%; C: 0.05% or less; P: 0.040% or less; and S: 0.040% or less, and the weight percent of C is 0.04% or less.

[00064] In an embodiment, a heat-resistant ferritic alloy material consists essentially of: Fe, and, by weight percent, Al: ~ 2% to ~ 6%; Si: ~ 2% to ~ 6%; Mn: ~ 0.3 to ~ 1.1%; C: 0.05% or less; P: 0.040% or less; and S: 0.040% or less, and the material forms an adherent ferroaluminosilicate oxide film. In an embodiment, the film provides resistance to at least one of: high temperature oxidation, cyclic oxidation scaling, erosion, carburization, and coking.

[00065] According to an embodiment disclosed herein, a steel is formed from a heat- resistant ferritic alloy material comprising Fe and, by weight percent, Al: ~ 2% to ~ 6%; Si: ~ 2% to ~ 6%; Mn: ~ 0.3 to ~ 1.1%; C: 0.05% or less; P: 0.040% or less; and S: 0.040% or less. In an embodiment, the steel so formed from the allow material has a transformation temperature from an alpha phase to a gamma phase of 1100 degrees C or higher.

[00066] In an embodiment, a steel is formed from a heat-resistant ferritic alloy material comprising Fe and, by weight percent, Al: ~ 2% to ~ 6%; Si: ~ 2% to ~ 6%; Mn: ~ 0.3 to ~ 1.1%; C: 0.05% or less; P: 0.040% or less; and S: 0.040% or less, and melting of the material to form the steel occurs without formation of a gamma phase.

[00067] In an embodiment, a steel is formed from a heat-resistant ferritic alloy material comprising Fe and, by weight percent, Al: ~ 2% to ~ 6%; Si: ~ 2% to ~ 6%; Mn: ~ 0.3 to ~ 1.1%; C: 0.05% or less; P: 0.040% or less; and S: 0.040% or less, and the steel is subjected to an annealing or stress relief treatment at a temperature at which an alpha phase is not transformed to a gamma phase.

[00068] In an embodiment, a steel is formed from a heat-resistant ferritic alloy material comprising Fe and, by weight percent, Al: ~ 2% to ~ 6%; Si: ~ 2% to ~ 6%; Mn: ~ 0.3 to ~ 1.1%; C: 0.05% or less; P: 0.040% or less; and S: 0.040% or less, and the steel is subjected to a surface treatment to provide enhanced surface performance. In an embodiment, the surface treatment is at least one of: catalytic coating, abrasion resistance coating, wear resistance coating, optical performance coating, infrared reflectance coating, infrared absorption coating, and thermal barrier coating.

[00069] According to an embodiment disclosed herein, a ferritic alloy powder used for additive manufacturing comprises Fe, and, by weight percent, Al: ~ 2% to ~ 6%; Si: ~ 2% to ~ 6%; Mn: ~ 0.3 to ~ 1.1%; C: 0.05% or less; P: 0.040% or less; and S: 0.040% or less. In an embodiment, the powder further comprises, by weight percent, ~ 1% or less of at least one of: Ti, Zr, Mo, Cr, Ni, Mg, Pt, Pd, Re, Au, Ag, Cu, Ir, Ru, Ce, Li, Na, K, Hf, and Rh.

[00070] According to an embodiment disclosed herein, a ferritic alloy powder used for additive manufacturing consists essentially of: Fe, and, by weight percent, Al: ~ 2% to ~ 6%; Si: ~ 2% to ~ 6%; Mn: ~ 0.3 to ~ 1.1%; C: 0.05% or less; P: 0.040% or less; and S: 0.040% or less.

[00071] According to an embodiment disclosed herein, a component is formed at least partly from a heat-resistant ferritic alloy material comprising Fe and, by weight percent, Al: ~ 2% to ~ 6%; Si: ~ 2% to ~ 6%; Mn: ~ 0.3 to ~ 1.1%; C: 0.05% or less; P: 0.040% or less; and S: 0.040% or less, and the component is one of: an exhaust system component, an exhaust manifold, an exhaust turbine component, an exhaust pipe, an exhaust aftertreatment component, an exhaust treatment catalyst, a diesel exhaust fluid mixer, a muffler, an exhaust gas recirculation component, an exhaust gas recirculation cooler, an exhaust gas recirculation valve, a turbocharger housing, a burner assembly component, a combustor body, a heat exchanger component, a boiler component, a gasifier body, a catalyst support, a fuel cell component, and an elevated temperature fuel cell component.

[00072] According to an embodiment disclosed herein, additive manufacturing is used to form a component at least partly from a ferritic alloy powder, the powder comprising: Fe, and, by weight percent, Al: ~ 2% to ~ 6%; Si: ~ 2% to ~ 6%; Mn: ~ 0.3 to ~ 1.1%; C: 0.05% or less; P: 0.040% or less; and S: 0.040% or less, and the component is one of: an exhaust system component, an exhaust manifold, an exhaust turbine component, an exhaust pipe, an exhaust aftertreatment component, an exhaust treatment catalyst, a diesel exhaust fluid mixer, a muffler, an exhaust gas recirculation component, an exhaust gas recirculation cooler, an exhaust gas recirculation valve, a turbocharger housing, a burner assembly component, a combustor body, a heat exchanger component, a boiler component, a gasifier body, a catalyst support, a fuel cell component, and an elevated temperature fuel cell component. [00073] According to an embodiment disclosed herein, a method of making a metallic component of an engine comprises: providing in a powdered form a material comprising: Fe, and, by weight percent, Al: ~ 3% to ~ 6%; Si: ~ 3% to ~ 6%; Mn: 0.3 to 0.6 %; C: 0.05% or less; P: 0.040% or less; and S: 0.040% or less; and subjecting the material to an additive manufacturing process to form the component from the material. In an embodiment, the method comprises subjecting the formed component to surface treatment to provide enhanced surface performance. In an embodiment, the surface treatment is at least one of: catalytic coating, abrasion resistance coating, wear resistance coating, optical performance coating, infrared reflectance coating, infrared absorption coating, and thermal barrier coating.

[00074] One of skill in the art may appreciate from the foregoing that unexpected benefits are derived from application of the material, powder, steel, component, and method disclosed herein to the problem of optimizing characteristics of engine components and the materials and methods used to make them. An unexpected benefit may be derived from application of the disclosed material, powder, steel, component, and method without the need for including or adding additional components, features, or method steps. A key benefit contemplated herein is improvement of characteristics of engine components and materials and methods used to make them through use of the disclosures herein, while excluding any additional components, materials, method steps, or changes in features of the foregoing. In this exclusion, maximum simplicity and cost containment may be effected. Accordingly, the substantial benefits of cost containment and maintaining simplicity of materials and manufacture may reside in an embodiment disclosed herein and consisting of, or consisting essentially of, features of the method, system, or apparatus disclosed herein. Thus, embodiments disclosed herein contemplate the exclusion of materials, steps, features, and components beyond those set forth herein. This disclosure contemplates, in some embodiments, the exclusion of certain materials, steps, features, and components that are set forth in this disclosure, even when such are identified as being included, preferred, and/or preferable.

[00075] It is to be understood that the above description is intended to be illustrative, and not restrictive. Many other embodiments will be apparent to those of skill in the art upon reading and understanding the above description. For example, it is contemplated that features described in association with one embodiment are optionally employed in addition or as an alternative to features described in association with another embodiment. The scope of the invention should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.