冷变形对节镍型奥氏体不锈钢组织性能的影响

Effect of cold rolling on microstructure and properties of low-nickle austenitic stainless steel

通过对一种亚稳定的节镍型奥氏体不锈钢进行了9.2%~68.4%的冷变形,研究冷变形压下率对材料性能的影响和组织演变规律。结果表明:α’-马氏体含量随着冷变形压下率的增加而不断地增加,并且与Angel模型相吻合;在冷变形压下率逐渐增加到17.1%的过程中,α’-马氏体和ε-马氏体同时存在,并且在剪切带交叉处形核,冷变形压下率继续增大时,大的板条α’-马氏体逐渐形成,ε-马氏体消失。屈服强度、抗拉强度、硬度和屈强比随着冷变形压下率的增加而增加,伸长率急剧地下降。在所研究压下率的范围内,抗拉强度(MPa)与维氏硬度(HV)在数值上存在着大约3倍的关系。

Cold rolling at a reduction ratio of 9. 2% ~ 68. 4% was carried out for a metastable low-nickle austenitic stainless steel,and the mechanical properties and microstructure evolution of the steel were studied. The results show that the martensite content increases with the increasing of deformation and a good agreement was found between the experiment results and the Angel model. The α'-martensite and ε-martensite exist at the same time and nucleate at the shear-band intersections with the increasing of the reduction ratio up to 17. 1%,however,the ε-martensite disappears while the α'-martensite constantly grows up when the reduction ratio continues to increase. The tensile strength,yield strength,hardness and the yield strength and tensile strength ratio increase with the increasing of the reduction ratio up to 68. 4%,while elongation decreases sharply. At the same time,the ratio of tensile strength to Vickers hardness is constant and approximately equal to three in all percentages of cold rolling.