冲击载荷下低屈服比高强钢板的拉伸性能  

Tensile Properties of High Strength Steel Sheet with Low Yield Ratio under Impact Loading

作　　者：郭军霞[1] 姚连登[2] 丁富连[2] 方健[2] 季京[2] 陈卓人[2] 

机构地区：[1]同济大学,上海200092 [2]宝钢股份公司,上海201900

出　　处：《宝钢技术》2006年第5期59-63,共5页Baosteel Technology

摘　　要：通过室温下的仪器化冲击试验和静态拉伸试验,研究一种低屈服比高强度钢板在冲击载荷下的力学性能和断裂机理。结果表明：试验钢的组织由细小岛状马氏体与针状铁素体为主构成,马氏体体积分数为27．6%。与静态拉伸性能相比,在名义应变速率为100 s^(-1)的冲击载荷作用下,试验用钢屈服强度提高31．6%,延伸率不降低。在静态和动态载荷下,该钢均以显微空洞长大聚集的方式发生韧性断裂,但显微空洞的形核和长大方式不同。在静态载荷下,显微空洞形核于颈缩区的铁素体晶粒内部或铁素体-马氏体两相界面处,空洞主要通过两相界面的脱开而形成长大；在动态载荷下,显微空洞主要形核于颈缩区的两相界面处,空洞主要通过马氏体粒子的开裂而形成长大。Mechanical properties and fracture mechanism of high strength steel sheet with low yield ratio under impact loading have been studied through instrumented impact and quasi-static tensile tests. The results showed that the microstructure of the steel was mainly composed of fine island-like martensite and acicular ferrite, with a 27, 6% of martensite volume fraction. Compared to that under quasi-static tensile loading, the yield strength of the steel increased by 31, 6% with no reduction of elongation under impact loading at the nominal strain rate of 100 s^-1 The fracture mode was dimple type under both loading conditions. Micruvoid mostly formed within the ferrite grains or at the ferrlte-martensite interfaces in the necking vicinity and the void grew up by the decohesion of ferrite-martensite interface under quasi-static tensile loading, while microvoid mainly developed at the ferrite-martensite interfaces in the necked region and the void grew up by the fracture of martensite particles under dynamic loading.

关 键 词：高强钢 马氏体形貌 拉伸断裂 

分 类 号：TG113.25[金属学及工艺—物理冶金]