层合轧压SMAT纳米化304不锈钢材料渐进损伤模拟

Progressive damage simulation of layered co-rolled SMATed 304 stainless steel

基于表面机械研磨处理技术(SMAT)和温轧工艺,可以加工出具有高强度和理想韧性的层合纳米化结构材料。为了研究层合轧压SMAT纳米化304不锈钢材料的变形行为及随后的损伤起始与演化过程,采用内聚有限元方法,建立了用于预测该材料力学性能的有限元模型。基于该模型,评估了材料中纳米晶层性质,包括法向内聚强度、切向内聚强度、损伤演化断裂能和体积含量对材料整体强度和韧性的影响。通过比较数值仿真结果与实验结果,验证了模型的合理性和准确性。同时预测结果表明,增加纳米晶层的内聚强度和减小其断裂能都能提高材料的韧性;增加纳米晶层的体积含量,材料的整体韧性降低,但强度增加。

Based on the techniques of surface mechanical attrition treatment（SMAT） and warm co-rolling,laminated and nanostructured materials with high strength and exceptional ductility could be produced.In order to study the deformation behavior and associated damage initiation/evolution process in the layered co-rolled SMATed 304 stainless steel,the cohesive finite element method（CFEM） was employed to generate a model which could be used to predict the mechanical properties of the material.Based on the model,the effects of nanograin layer properties such as normal cohesive strength,tangential cohesive strength,fracture energy and volume fraction on the overall strength and ductility were investigated.The comparison between simulation result and experimental result demonstrates that the model is reasonable and accurate.Meanwhile,the predicted results indicate that the ductility of material increases with the increasing of nanograin layer cohesive strength and the decreasing of nanograin layer fracture energy.With increasing the volume fraction of the nanograin layer,the ductility of the material reduces,but the strength increases.