冷轧压下量对汽车车身用高强不锈钢组织和力学性能的影响

Effect of Cold Rolling Reduction on Microstructure and Mechanical Properties of High Strength Stainless Steel for Automobile Body

节能降耗使高强度不锈钢成为汽车车身材料的首选。本文主要研究了冷轧压下量对车身用不锈钢力学性能和微观组织的影响规律。结果表明:抗拉强度和硬度都随着冷轧压下量的提高而提高,在冷轧压下量为66.7%时达到最高,其抗拉强度为1860 MPa,维氏硬度为544.4 HV;其塑性随压下量增大而降低,在冷轧压下量为75%时达最低值1.93%。材料经冷轧后,晶粒有明显的伸长变形,随压下量增大,断口形貌出现明显的解理特征,有脆性断裂趋势。EDS分析表明,随压下量增加,第二相中Cr元素含量先增加后减小,Ni、Mn含量下降。

Energy saving and consumption reduction make high strength stainless steel become the first choice of automobile body material.The influence of cold rolling reduction on the mechanical properties and microstructure of the stainless steel for automobile bodies was studied.The results show that the tensile strength and hardness increase with the increase of cold rolling reduction and reach the peak values of 1860 MPa and 544.4 HV separately when the cold rolling reduction is 66.7%.The plasticity decreases with the increase of the cold rolling reduction,reaching the lowest value of 1.93%when the cold rolling reduction is 75%.After cold rolling,the grains have obvious extended deformation,and with the increase of reduction,the fracture morphology has obvious cleavage characteristics,which has the trend of brittle fracture.EDS analysis shows that with the increase of reduction Cr content in second phase increases first then decreases and the Ni and Mn contens decrease.