汽车用SPHC热轧薄钢板的低周疲劳特性  

Low Cycle Fatigue Characteristics of SPHC Hot-rolled Steel Sheet for Automobile

作　　者：孙晓冉 宋月 谷秀锐 白丽娟 赵秀娟 SUN Xiaoran;SONG Yue;GU Xiurui;BAI Lijuan;ZHAO Xiujuan(HBIS Group Technology Research Institute,Shijiazhuang 052160,China;Department of Materials Engineering,Hebei College of Industry and Technology,Shijiazhuang 050091,China)

机构地区：[1]河钢集团钢研总院理化检测中心,石家庄052160 [2]河北工业职业技术学院材料工程系,石家庄050091

出　　处：《机械工程材料》2021年第4期57-60,共4页Materials For Mechanical Engineering

基　　金：河钢集团重点科技项目(HG2018215)。

摘　　要：对20 mm厚汽车用SPHC热轧薄钢板进行低周循环应变疲劳试验,获得了应力-应变曲线、应变寿命曲线、应变滞回环曲线以及相关疲劳常数指标,并对疲劳断口形貌进行观察。结果表明:SPHC钢在试验范围内具有非Masing效应;拟合得到SPHC钢的循环强度系数为284,循环应变硬化指数为0.128;通过Manson-Coffin方程拟合得到SPHC钢的疲劳强度系数为467 MPa,疲劳强度指数为-0.078,疲劳延性系数为0.323,疲劳延性指数为-0.609;疲劳断口由裂纹源区、裂纹扩展区、瞬断区组成,裂纹扩展区由大量疲劳辉纹组成,瞬断区存在大量韧窝,SPHC钢具有良好的塑韧性。Low cycle cyclic strain fatigue test was carried out on 2.0 mm thick SPHC hot-rolled steel sheet for automobile,and the stress-strain curve,strain-life curve,strain hysteresis loop curve and related fatigue constant indicators were obtained.The fatigue fracture morphology was observed.The results show that the SPHC steel had a non-Masing effect within the test range.The fitted cyclic strength coefficient of SPHC steel was 284,and cyclic strain-hardening exponent was 0.128.The fatigue strength coefficient was 467 MPa,the fatigue strength index was-0.078,the fatigue ductility coefficient was 0.323,and the fatigue ductility index was-0.609 fitted by Manson-Coffin equation.The fatigue fracture included crack source area,crack propagation area,and transient fracture area.The crack propagation area was composed of a large number of fatigue striation,and the transient fracture area consisted of a large number of dimples.SPHC steel had good ductility.

关 键 词：SPHC钢 低周疲劳特性 应变控制 疲劳断口 

分 类 号：TG142[一般工业技术—材料科学与工程]