Ut-battelle, Inc.

Caterpillar Inc.

The United States of America As Represented by the United States

Martin Marietta Energy Systems, Inc.

Other

Fca US LLC

Nemak Usa, Inc.

Philip J Maziasz

Robert W Swindeman

Vinod Kumar Sikka

Govindarajan Muralidharan

Michael P Brady

Michael James Pollard

Ronald L Klueh

Bruce A Pint

Chad W Siebenaler

Tim McGreevy

Michael Leonard Santella

Yukinori Yamamoto

Roman I Pankiw

Gene M Goodwin

Chain-tsuan Liu

David N Braski

Chain T Liu

Amit Shyam

Adrian Stefan Sabau

Sudarsanam Suresh Babu

Arthur F Rowcliffe

Karren Leslie More

Ying Yang

James A Haynes

Andres Fernando Rodriguez-Jasso

Joachim Hugo Schneibel

Seyed Mirmiran

Christopher R Glaspie

Dongwon Shin

Kinga A Unocic

Joseph D Vought

Jose A Gonzalez-Villarreal

Naoyuki Hashimoto

Zhao P Lu

Bing Yang

Maan H Jawad

Alan M Paris

Lin Zhang

Jose Talamantes-Silva

Shibayan Roy

Timothy E Mcgreevy

The present disclosure concerns embodiments of aluminum alloy compositions exhibiting microstructural stability and strength at high temperatures. The disclosed aluminum alloy compositions comprise particular combinations of components that contribute the ability of the compositions to exhibit improved microstructural stability and hot tearing resistance as compared to conventional alloys. Also disclosed herein are embodiments of methods of making and using the alloys.

Aluminum alloy compositions and methods of making and using the same

An air castable Fe-based stainless steel alloy comprises in weight % based on the total weight of the alloy 18-22% Cr, 15-22% Ni, 3-6% Al, 0.5-5% Mn, 0-3.5% W, 0-5% Cu, 0-2% Si, 1-2.5% Nb, 0.3-0.6% C balance Fe wherein, Cu+W+Si=0.5-10.5, and the alloy provides an oxidation resistance of 0.5&#x3c;specific mass change&#x3c;+2 mg/cmafter 400 one hour cycles at 900&#xb0; C. in 10% water vapor.

Low-cost cast creep-resistant austenitic stainless steels that form alumina for high temperature oxidation resistance

The present invention addresses the need for new austenitic steel compositions with higher creep strength and higher upper temperatures. The new austenitic steel compositions retain desirable phases, such as austenite, MC, and MC in its microstructure to higher temperatures. The present invention also discloses a methodology for the development of new austenitic steel compositions with higher creep strength and higher upper temperatures.

Cast heat-resistant austenitic steel with improved temperature creep properties and balanced alloying element additions and methodology for development of the same

A cast, austenitic steel composed essentially of, expressed in weight percent of the total composition, about 0.4 to about 0.7 C, about 20 to about 30 Cr, about 20 to about 30 Ni, about 0.5 to about 1 Mn, about 0.6 to about 2 Si, about 0.05 to about 1 Nb, about 0.05 to about 1 W, about 0.05 to about 1.0 Mo, balance Fe, the steel being essentially free of Ti and Co, the steel characterized by at least one microstructural component selected from the group consisting of MC, MC, and M(C, N).

Cast, heat-resistant austenitic stainless steels having reduced alloying element content

A corrosion resistant electrically conductive component that can be used as a bipolar plate in a PEM fuel cell application is composed of an alloy substrate which has 10-30 wt. % Cr, 0.5 to 7 wt. % V, and base metal being Fe, and a continuous surface layer of chromium nitride and vanadium nitride essentially free of base metal. A oxide layer of chromium vanadium oxide can be disposed between the alloy substrate and the continuous surface nitride layer. A method to prepare the corrosion resistant electrically conductive component involves a two-step nitridization sequence by exposing the alloy to a oxygen containing gas at an elevated temperature, and subsequently exposing the alloy to an oxygen free nitrogen containing gas at an elevated temperature to yield a component where a continuous chromium nitride layer free of iron has formed at the surface.

Iron-based alloy and nitridation treatment for PEM fuel cell bipolar plates

A CF8C type stainless steel alloy and articles formed therefrom containing about 18.0 weight percent to about 22.0 weight percent chromium and 11.0 weight percent to about 14.0 weight percent nickel; from about 0.05 weight percent to about 0.15 weight percent carbon; from about 2.0 weight percent to about 10.0 weight percent manganese; and from about 0.3 weight percent to about 1.5 weight percent niobium. The present alloys further include less than 0.15 weight percent sulfur which provides high temperature strength both in the matrix and at the grain boundaries without reducing ductility due to cracking along boundaries with continuous or nearly-continuous carbides. The disclosed alloys also have increased nitrogen solubility thereby enhancing strength at all temperatures because nitride precipitates or nitrogen porosity during casting are not observed. The solubility of nitrogen is dramatically enhanced by the presence of manganese, which also retains or improves the solubility of carbon thereby providing additional solid solution strengthening due to the presence of manganese and nitrogen, and combined carbon.

Heat and corrosion resistant cast CF8C stainless steel with improved high temperature strength and ductility

An austenitic stainless steel alloy includes, in weight percent: &#x3e;4 to 15 Mn; 8 to 15 Ni; 14 to 16 Cr; 2.4 to 3 Al; 0.4 to 1 total of at least one of Nb and Ta; 0.05 to 0.2 C; 0.01 to 0.02 B; no more than 0.3 of combined Ti+V; up to 3 Mo; up to 3 Co; up to 1W; up to 3 Cu; up to 1 Si; up to 0.05 P; up to 1 total of at least one of Y, La, Ce, Hf, and Zr; less than 0.05 N; and base Fe, wherein the weight percent Fe is greater than the weight percent Ni, and wherein the alloy forms an external continuous scale including alumina, nanometer scale sized particles distributed throughout the microstructure, the particles including at least one of NbC and TaC, and a stable essentially single phase FCC austenitic matrix microstructure that is essentially delta-ferrite-free and essentially BCC-phase-free.

High Mn austenitic stainless steel

An austenitic stainless steel displaying high temperature oxidation and creep resistance has a composition that includes in weight percent 15 to 21 Ni, 10 to 15 Cr, 2 to 3.5 Al, 0.1 to 1 Nb, and 0.05 to 0.15 C, and that is free of or has very low levels of N, Ti and V. The alloy forms an external continuous alumina protective scale to provide a high oxidation resistance at temperatures of 700 to 800&#xb0; C. and forms NbC nanocarbides and a stable essentially single phase fcc austenitic matrix microstructure to give high strength and high creep resistance at these temperatures.

Oxidation resistant high creep strength austenitic stainless steel

A cast stainless steel alloy and articles formed therefrom containing about 0.5 wt. % to about 10 wt. % manganese, 0.02 wt. % to 0.50 wt. % N, and less than 0.15 wt. % sulfur provides high temperature strength both in the matrix and at the grain boundaries without reducing ductility due to cracking along boundaries with continuous or nearly-continuous carbides. Alloys of the present invention also have increased nitrogen solubility thereby enhancing strength at all temperatures because nitride precipitates or nitrogen porosity during casting are not observed. The solubility of nitrogen is dramatically enhanced by the presence of manganese, which also retains or improves the solubility of carbon thereby providing additional solid solution strengthening due to the presence of manganese and nitrogen, and combined carbon. Such solution strengthening enhances the high temperature precipitation-strengthening benefits of fine dispersions of NbC. Such solid solution effects also enhance the stability of the austenite matrix from resistance to excess sigma phase or chrome carbide formation at higher service temperatures. The presence of sulfides is substantially eliminated.

Heat and corrosion resistant cast CN-12 type stainless steel with improved high temperature strength and ductility

A method of making a steel composition includes the steps of:

Nano-scale nitride-particle-strengthened high-temperature wrought ferritic and martensitic steels

A wrought stainless steel alloy composition includes 12% to 25% Cr, 8% to 25% Ni, 0.05% to 1% Nb, 0.05% to 10% Mn, 0.02% to 0.15% C, 0.02% to 0.5% N, with the balance iron, the composition having the capability of developing an engineered microstructure at a temperature above 550&#xb0; C. The engineered microstructure includes an austenite matrix having therein a dispersion of intragranular NbC precipitates in a concentration in the range of 10to 10precipitates per cm.

Wrought stainless steel compositions having engineered microstructures for improved heat resistance

A corrosion resistant, electrically conductive component such as a bipolar plate for a PEM fuel cell includes 20&#x2013;55% Cr, balance base metal such as Ni, Fe, or Co, the component having thereon a substantially external, continuous layer of chromium nitride.

Corrosion resistant metallic bipolar plate

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Oak Ridge, TN, United States of America

Philip J Maziasz