摘要
通过圆筒拉深试验研究了1 200 MPa级超高强度双相钢板(DP1200)和纯马氏体钢板(M1200)的极限拉深成形性能,采用扫描电子显微镜观察分析了钢板的微观组织形貌与结构,探讨了其微观组织结构与断裂机理的关系.结果表明:DP1200和M1200的极限拉延比分别为2.03和1.99,其单向拉伸性能不能准确地反映钢板材料在复杂应力状态下的成形性能;2种钢板的断裂模式均为断口分布着大量韧窝的韧性断裂,但其裂纹扩展机理不同.DP1200中的裂纹是以沿铁素体/马氏体相界为主,兼有穿过马氏体相并扩展的失效模式;而M1200钢中的裂纹是沿马氏体晶界扩展的失效模式.
The limit drawing formability of two advanced high strength steel sheets （AHSS） of tensile strength 1 200 MPa with the cup drawing test was studied. Their instability and failure mechanisms were also discussed from the standpoint of the microstructure. The results show that the limiting drawing ratio （I.DR） of theDP1200 and the M1200 are 2. 03 and 1.99, respectively. Their uniaxial tensile properties are difficult to accurately reflect the forming performance of material under the complex stress state. A large number of dimples on the fracture surfaces can be seen, which testifies the ductile fracture mode, but the crack propagation mechanism is not the same. For DP1200 steel, the failure mode is the crack propagation along the ferrite/martensite interfaces as well as through the martensitic grains. In M1200 steel, the crack propagates along the martensite interfaces.
出处
《上海交通大学学报》
EI
CAS
CSCD
北大核心
2012年第9期1466-1470,1481,共6页
Journal of Shanghai Jiaotong University
基金
国家自然科学基金项目(51005144)
上海汽车工业科技发展基金(1009)
上海市数字化汽车车身工程重点实验室开放基金项目(2012002)资助
关键词
超高强度钢板
双相钢
成形性能
断裂
扩展机理
advanced high strength steel sheet （AHSS）
dual-phase steel
formabiIity
fracture
propaga-ion mechanism
