Final published version
Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - A combined optimization of alloy composition and aging temperature in designing new UHS precipitation hardenable stainless steels
AU - Xu, W.
AU - Castillo, P. E J Rivera Díaz del
AU - Zwaag, S. van der
PY - 2009/4
Y1 - 2009/4
N2 - Alloy composition and proper heat treatment conditions are of paramount importance in maximising mechanical properties of precipitation hardenable stainless steels. Three base stainless steel alloys for ultimate strength levels employing carbides, Cu particles and/or Ni-rich precipitates are designed via a computational approach coupling a genetic algorithm with optimization criteria based on thermodynamic, kinetic and mechanical principles. The combined effects of 11 alloying elements (Al, C, Co, Cr, Cu, Mo, Nb, Ni, Si, Ti and V) are investigated on the basis of: a suitable martensite start (Ms) temperature, the suppression of undesirable phases, a minimal Cr concentration in the matrix and the potency of the precipitation strengthening contribution. The optimal aging temperature is derived from precipitation strengthening optimization and predicted values match experimental optima for existing alloy grades rather well. This thermodynamic justification of optimal precipitation temperatures in UHS steels has not been given before. For the optimized alloys considered the results of a sequential optimization of composition and precipitation temperature do not differ significantly from those of an integrated optimization.
AB - Alloy composition and proper heat treatment conditions are of paramount importance in maximising mechanical properties of precipitation hardenable stainless steels. Three base stainless steel alloys for ultimate strength levels employing carbides, Cu particles and/or Ni-rich precipitates are designed via a computational approach coupling a genetic algorithm with optimization criteria based on thermodynamic, kinetic and mechanical principles. The combined effects of 11 alloying elements (Al, C, Co, Cr, Cu, Mo, Nb, Ni, Si, Ti and V) are investigated on the basis of: a suitable martensite start (Ms) temperature, the suppression of undesirable phases, a minimal Cr concentration in the matrix and the potency of the precipitation strengthening contribution. The optimal aging temperature is derived from precipitation strengthening optimization and predicted values match experimental optima for existing alloy grades rather well. This thermodynamic justification of optimal precipitation temperatures in UHS steels has not been given before. For the optimized alloys considered the results of a sequential optimization of composition and precipitation temperature do not differ significantly from those of an integrated optimization.
KW - Alloy design
KW - Composition effect
KW - Genetic algorithm
KW - Precipitate
KW - Stainless steel
KW - Temperature effect
KW - Thermodynamics
U2 - 10.1016/j.commatsci.2008.11.006
DO - 10.1016/j.commatsci.2008.11.006
M3 - Journal article
AN - SCOPUS:62149121684
VL - 45
SP - 467
EP - 473
JO - Computational Materials Science
JF - Computational Materials Science
SN - 0927-0256
IS - 2
ER -