冷轧工艺对奥氏体不锈钢组织性能的影响

The effect of cold rolling regime on the microstructure and properties of austenitic stainless steel

通过对亚稳定奥氏体不锈钢SUS301L和稳定奥氏体不锈钢SUS309进行10％～70％的冷轧变形，研究了两个典型奥氏体不锈钢的组织和力学性能演变。结果表明，SUS301L不锈钢在冷轧变形过程中发生形变马氏体的转变，马氏体形核于剪切带的交叉点处，形核点的不断连接长大成为板条的形变马氏体；而SUS309通过滑移来协调塑性变形，冷变形过程中不发生马氏体转变。二者均有明显的加工硬化，即硬度和强度均随着冷轧变形量的增加而升高，延伸率表现为相反的趋势。但SUS301L是位错累积和形变马氏体转变量增加的综合作用。而SUS309仅是位错不断累积增多的结果。

Cold rolling at a reduction ratio of 10%- 70% was carried out for SUS301L metastable austenitie stainless steel and SUS309 stable austenitic stainless steel. The evolution of microstructure and mechanical properties was studied. The results showed that transformation of deformation-induced martensite occurred during the cold deformation of SUS301L. The martensite nucleated at the shear-band intersections and the growth occured by the repeated nucleation of new embryos of deformation-induced lath martensite However, SUS309 coordinated plastic deformation by slip and no martensite transformation occurred during cold deformation. Work- hardening was obvious for both steels, that is, the hardness and strength increased with the increase of cold reduction, while the elongation changed in the opposite direction. The work-hardening of SUS301L could be explained by the dislocation accumulation and the increase of deformation- induced martensite. However, the work-hardening of SUS309 was merely the result of increasing dislocation density.