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.
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)
出处
《机械工程材料》
CAS
CSCD
北大核心
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)。
关键词
SPHC钢
低周疲劳特性
应变控制
疲劳断口
SPHC steel
low cycle fatigue characteristic
strain control
fatigue fracture
