晶界碳化物对15Cr-25Ni不锈钢拉伸性能的影响

Effect of Grain Boundary Carbides on Tensile Properties of 15Cr-25Ni Stainless Steel

利用单相奥氏体及晶界碳化物＋奥氏体的两种 １５Ｃｒ－２５Ｎｉ不锈钢，研究了晶界碳化物对室温及８６０℃拉伸性能的影响。结果表明，室温下晶界碳化物对屈服强度几乎没有影响，但提高了抗拉强度约１４％，降低材料塑性（断面收缩率）约３８％，在８５０℃，晶界碳化物对抗拉强度没有影响，但提高了村料的塑性，其延伸率反断面收缩率分别提高约７０％和５８％，探讨了晶界碳化物影响拉伸性能的机制，室温下由于碳化物与基体界面结构与晶界结构不同导致与位错的不同交互作用，在高温下则是晶界碳化物阻碍晶界的滑移。

Effect of grain boundary carbides on tensile properties of l5Cr-25Ni stainless steel at room temperature and 850℃ have been investigated by comparing the single phase austenitic steel with the grainbondary carbides precipitation steel. The results show that grain boundary carbides have little influence on yield stress, but increase ultimate tensile strength by about 14% and decrease the reduction in area by 83% at room temperature. At 850℃ grain boundary carbides have no effect on ultimate tensile strength, but the reduction in area and elongation are decreased by 70% and 58% respectively. The mechanism of the grain boundary carbides effect has been discussed. At room temperature different structures of grain boundary and carbide. matrix interface lead to different interactions of dislocation with these interfaces and at 850℃, effect of carbides is mainly due to grain boundary sliding inhibition by these grain boundary carbides.