中文摘要：

在800℃下对铝热法制备的微钠结构316L不锈钢进行了不同时间退火处理,利用XRD、SEM等分析了退火过程中的组织演变,并测试了力学性能。结果表明：随退火时间延长,微米晶奥氏体体积分数增大,纳米晶奥氏体晶粒尺寸变化不明显,铁素体体积分数逐渐增加;退火时间大于4 h,微米晶奥氏体体积分数明显增大,改善了铸态组织因纳米晶无法储存足够位错而导致的加工硬化能力弱的问题,此时抗拉强度达499 MPa,屈服强度为236 MPa,伸长率随退火时间的延长先增大后急剧下降,退火4 h后伸长率达24%,材料塑性得以优化。

英文摘要：

Micronano structure 316L stainless steel prepared by aluminothermic reaction was annealed at 800℃ for different time, microstrueture evolution during annealing was investigated by X-ray diffraction and scanning electron microscope, and mechanical properties were also tested. The test results show that with annealing time increasing, the volume fraction of mierocrystalline austenite and ferrite increase gradually, and the grain size change of nanoerystalline austenite is not obvious. When annealing time more than 4 h, the tensile strength is 499 MPa and yield strength is 236 MPa because of that the volume fraction of microcrystalline austenite increase significantly which improve the poor work hardening ability of casting structures caused by nanoerystalline cannot store enough dislocation. With annealing time extending, the elongation increases first and then decreases sharply, and reaches to 24% after annealing for 4 h, the plasticity of the steel can be optimized.