TY - JOUR
T1 - Evaluation of Mn substitution for Ni in alumina-forming austenitic stainless steels
AU - Yamamoto, Y.
AU - Santella, M. L.
AU - Liu, C. T.
AU - Evans, N. D.
AU - Maziasz, P. J.
AU - Brady, M. P.
PY - 2009/10/25
Y1 - 2009/10/25
N2 - There has been increasing interest in the substitution of low-cost Mn for Ni in austenitic stainless steels due to the rising price of Ni. This paper investigates the possibility of such a substitution approach for the recently developed alumina (Al2O3)-forming austenitic (AFA) class of heat-resistant stainless steels. Computational thermodynamic tools were utilized to predict the alloy composition range to maintain an austenitic matrix microstructure when Mn is substituted for Ni in the presence of Al, which is a strong body-centered-cubic (BCC) phase stabilizer. Phase equilibria, oxidation behavior, and creep properties of Fe-(10-14)Cr-(5-15)Mn-(4-12)Ni-(2.5-3)Al-Cu-Nb-C-B (in weight percent) based alloys were studied. The alloys based on Fe-14Cr-2.5Al-(5-9)Mn-(10-12)Ni exhibited the best balance of oxidation and creep resistance, which represents approximately 50% reduction in Ni content compared to previously developed AFA alloys. These low-Ni, high-Mn AFA alloys formed protective Al2O3 scales up to 973-1073 K in air and at 923 K in air with 10% water vapor. Creep-rupture lives of the alloys under a severe screening condition of 1023 K and 100 MPa were in the 7.2 × 105-1.8 × 106 s (200-500 h) range, which is comparable to or somewhat improved over that of type 347 stainless steel (Fe-18Cr-11Ni base).
AB - There has been increasing interest in the substitution of low-cost Mn for Ni in austenitic stainless steels due to the rising price of Ni. This paper investigates the possibility of such a substitution approach for the recently developed alumina (Al2O3)-forming austenitic (AFA) class of heat-resistant stainless steels. Computational thermodynamic tools were utilized to predict the alloy composition range to maintain an austenitic matrix microstructure when Mn is substituted for Ni in the presence of Al, which is a strong body-centered-cubic (BCC) phase stabilizer. Phase equilibria, oxidation behavior, and creep properties of Fe-(10-14)Cr-(5-15)Mn-(4-12)Ni-(2.5-3)Al-Cu-Nb-C-B (in weight percent) based alloys were studied. The alloys based on Fe-14Cr-2.5Al-(5-9)Mn-(10-12)Ni exhibited the best balance of oxidation and creep resistance, which represents approximately 50% reduction in Ni content compared to previously developed AFA alloys. These low-Ni, high-Mn AFA alloys formed protective Al2O3 scales up to 973-1073 K in air and at 923 K in air with 10% water vapor. Creep-rupture lives of the alloys under a severe screening condition of 1023 K and 100 MPa were in the 7.2 × 105-1.8 × 106 s (200-500 h) range, which is comparable to or somewhat improved over that of type 347 stainless steel (Fe-18Cr-11Ni base).
KW - Alumina-forming
KW - Austenitic stainless steels
KW - High-Mn containing alloys
UR - http://www.scopus.com/inward/record.url?scp=69249172073&partnerID=8YFLogxK
U2 - 10.1016/j.msea.2009.06.043
DO - 10.1016/j.msea.2009.06.043
M3 - Article
AN - SCOPUS:69249172073
SN - 0921-5093
VL - 524
SP - 176
EP - 185
JO - Materials Science and Engineering: A
JF - Materials Science and Engineering: A
IS - 1-2
ER -