摘要:
One or more embodiments relates to a high-temperature, titanium alloyed, 9 Cr-1 Mo steel exhibiting improved creep strength and oxidation resistance at service temperatures up to 650° C. The 9 Cr-1 Mo steel has a tempered martensite microstructure and is comprised of both large (0.5-3 μm) primary titanium carbides and small (5-50 nm) secondary titanium carbides in a ratio of. from about 1:1.5 to about 1.5:1. The 9 Cr-1 Mo steel may be fabricated using exemplary austenizing, rapid cooling, and tempering steps without subsequent hot working requirements. The 9 Cr-1 Mo steel exhibits improvements in total mass gain, yield strength, and time-to-rupture over ASTM P91 and ASTM P92 at the temperature and time conditions examined.
摘要:
The invention relates to a composition and heat treatment for a high-temperature, titanium alloyed, 9 Cr-1 Mo steel exhibiting improved creep strength and oxidation resistance at service temperatures up to 650° C. The novel combination of composition and heat treatment produces a heat treated material containing both large primary titanium carbides and small secondary titanium carbides. The primary titanium carbides contribute to creep strength while the secondary titanium carbides act to maintain a higher level of chromium in the finished steel for increased oxidation resistance, and strengthen the steel by impeding the movement of dislocations through the crystal structure. The heat treated material provides improved performance at comparable cost to commonly used high-temperature steels such as ASTM P91 and ASTM P92, and requires heat treatment consisting solely of austenization, rapid cooling, tempering, and final cooling, avoiding the need for any hot-working in the austenite temperature range.
摘要:
One or more embodiments relates to an MCrAlY bond coat comprising an MCrAlY layer in contact with a Y—Al2O3 layer. The MCrAlY layer is comprised of a γ-M solid solution, a β-MAl intermetallic phase, and Y-type intermetallics. The Y—Al2O3 layer is comprised of Yttrium atoms coordinated with oxygen atoms comprising the Al2O3 lattice. Both the MCrAlY layer and the Y—Al2O3 layer have a substantial absence of Y—Al oxides, providing advantage in the maintainability of the Yttrium reservoir within the MCrAlY bulk. The MCrAlY bond coat may be fabricated through application of a Y2O3 paste to an MCrAlY material, followed by heating in a non-oxidizing environment.
摘要翻译:一个或多个实施方案涉及包含与Y-Al 2 O 3层接触的MCrAlY层的MCrAlY粘合涂层。 MCrAlY层由γ-M固溶体,金属间化合物相和Y型金属间化合物构成。 Y-Al 2 O 3层由与包含Al 2 O 3晶格的氧原子配位的钇原子组成。 MCrAlY层和Y-Al2O3层都基本上不存在Y-Al氧化物,提供了钇储层在MCrAlY体内的可维护性的优点。 MCrAlY粘合涂层可以通过将Y 2 O 3糊剂施加到MCrAlY材料,然后在非氧化环境中加热来制造。
摘要:
The disclosure provides a creep resistant alloy having an overall composition comprised of iron, chromium, molybdenum, carbon, manganese, silicon, nickel, vanadium, niobium, nitrogen, tungsten, cobalt, tantalum, boron, copper, and potentially additional elements. In an embodiment, the creep resistant alloy has a molybdenum equivalent Mo(eq) from 1.475 to 1.700 wt. % and a quantity (C+N) from 0.145 to 0.205. The overall composition ameliorates sources of microstructural instability such as coarsening of M23C6carbides and MX precipitates, and mitigates or eliminates Laves and Z-phase formation. A creep resistant martensitic steel may be fabricated by preparing a melt comprised of the overall composition followed by at least austenizing and tempering. The creep resistant alloy exhibits improved high-temperature creep strength in the temperature environment of around 650° C.
摘要:
The disclosure provides a creep resistant alloy having an overall composition comprised of iron, chromium, molybdenum, carbon, manganese, silicon, nickel, vanadium, niobium, nitrogen, tungsten, cobalt, tantalum, boron, and potentially additional elements. In an embodiment, the creep resistant alloy has a molybdenum equivalent Mo(eq) from 1.475 to 1.700 wt. % and a quantity (C+N) from 0.145 to 0.205. The overall composition ameliorates sources of microstructural instability such as coarsening of M23C6 carbides and MX precipitates, and mitigates or eliminates Laves and Z-phase formation. A creep resistant martensitic steel may be fabricated by preparing a melt comprised of the overall composition followed by at least austenizing and tempering. The creep resistant alloy exhibits improved high-temperature creep strength in the temperature environment of around 650° C.
摘要:
Superconductors formed by powder metallurgy have a matrix of niobium-titanium alloy with discrete pinning centers distributed therein which are formed of a compatible metal. The artificial pinning centers in the Nb-Ti matrix are reduced in size by processing steps to sizes on the order of the coherence length, typically in the range of 1 to 10 nm. To produce the superconductor, powders of body centered cubic Nb-Ti alloy and the second phase flux pinning material, such as Nb, are mixed in the desired percentages. The mixture is then isostatically pressed, sintered at a selected temperature and selected time to produce a cohesive structure having desired characteristics without undue chemical reaction, the sintered billet is reduced in size by deformation, such as by swaging, the swaged sample receives heat treatment and recrystallization and additional swaging, if necessary, and is then sheathed in a normal conducting sheath, and the sheathed material is drawn into a wire. The resulting superconducting wire has second phase flux pinning centers distributed therein which provide enhanced J.sub.ct due to the flux pinning effects.
摘要:
One or more embodiments relates to a method of producing an MCrAlY bond coat comprising an MCrAlY layer in contact with a Y—Al2O3 layer. The MCrAlY layer is comprised of a γ-M solid solution, a β-MAl intermetallic phase, and Y-type intermetallics. The Y—Al2O3 layer is comprised of Yttrium atoms coordinated with oxygen atoms comprising the Al2O3 lattice. The method comprises depositing an MCrAlY material on a substrate, applying an Y2O3 paste, and heating the substrate in a non-oxidizing atmosphere at a temperature between 400-1300° C. for a time sufficient to generate the Y—Al2O3 layer. Both the MCrAlY layer and the Y—Al2O3 layer have a substantial absence of Y2O3, YAG, and YAP phases.
摘要翻译:一个或多个实施方案涉及制备包含与Y-Al 2 O 3层接触的MCrAlY层的MCrAlY粘合涂层的方法。 MCrAlY层由γ-M固溶体,β-MA1金属间相和Y型金属间化合物构成。 Y-Al 2 O 3层由与包含Al 2 O 3晶格的氧原子配位的钇原子组成。 该方法包括在衬底上沉积MCrAlY材料,施加Y 2 O 3糊剂,并在400-1300℃的温度下在非氧化性气氛中加热衬底足以产生Y-Al 2 O 3层的时间。 MCrAlY层和Y-Al2O3层都基本上没有Y2O3,YAG和YAP相。
摘要:
A method of applying a cerium diffusion coating to a preferred nickel base alloy substrate has been discovered. A cerium oxide paste containing a halide activator is applied to the polished substrate and then dried. The workpiece is heated in a non-oxidizing atmosphere to diffuse cerium into the substrate. After cooling, any remaining cerium oxide is removed. The resulting cerium diffusion coating on the nickel base substrate demonstrates improved resistance to oxidation. Cerium coated alloys are particularly useful as components in a solid oxide fuel cell (SOFC).