Constitutive Analysis in Hot Working of a Nb Heavily Alloyed Stainless Steel
AISI 347 is an austenitic stainless steel heavily alloyed by around 0.7％Nb, which is much larger than the average content of Nb in the microalloyed steels. In this paper, hot working of AISI 347 SS was simulated by the uniaxial compression tests in a thermomechanic simulator, Thermecmaster Z. Its stress strain curves were measured at the various strain rates and deformation temperatures. All flow curves, at temperatures between 970～1230 ℃ and strain rates of 0.04-40/s, show a typical characteristics, i.e. stress increases with increasing strain without a peak stress observed.Numerical simulations on these flow curves shows that they can not be simulated by the well known equation in the literature σHW =σ0 + B1-exp(-cε)m, but by a modified one σ=B1-exp(-cε)mn + k(ε-εs). The five coefficients in the modified equation are dependent on the strain rate and deformation temperature, such dependence has been quantified by the least square fitting method in this paper. Finally, a mathematic model is developed and can successfully describe stress-strain curves at various strain rates and temperatures for the hot working of AISI 347 SS.
LUO Hai-wen LI Hong FANG Xu-dong
Institute for Structural Material of Central Iron and Steel Research Institute, Beijing 100081, Chin R&D Center of Taiyuan Iron and Steel Group Co.Ltd, Taiyuan 030003,China
国际会议
北京
英文
179-182
2007-09-18（万方平台首次上网日期，不代表论文的发表时间）