Effects of Various Alloying Elements on Tensile Properties of High-Purity Fe-18Cr-(14-16)Ni Alloys at Room Temperature

摘要

High-purity Fe-18Cr-14Ni/Si, Mn, P, S, C, N alloys and high-purity Fe-18Cr-16Ni/Mo alloys were prepared by a cold crucible method to investigate the intrinsic effects of alloying elements on the tensile properties of Fe-18Cr-(14-16)Ni alloys at room temperature. The results show that C and N interstitials had the greatest solid-solution strengthening effect, followed by the ferrite-forming substitutional elements Mo and Si, while Mn, P and S, had little or no solid-solution strengthening effect. Grain refinement caused a decrease in elongation and an increase in tensile strength and the magnitude was considerable in Fe-18Cr-16Ni-Mo alloys. The addition of Mo to Fe-18Cr-16Ni alloys caused an increase in both the internal stress sigma_0 and coefficient k in the Hall-Petch relation (sigma_(0.2) = sigma_0 + kd~(-1/2); where sigma_(0.2), d, and sigma_0 and k are 0.2 percent proof stress, grain diameter, and constants, respectively). The 0.2 percent proof stress of high-purity Fe-18Cr-16Ni alloys obeyed the equation, 0.2 percent PS (MPa) = 80.9 + 19.4(Mo) + {0.314 + 0.048(Mo)} X d~(-1/2), where the parentheses indicate Mo content in at percent and d is the average grain size in m.