连续退火与连续热镀锌590MPa级双相钢的疲劳性能

Fatigue properties of continuous-annealed and continuous hot-dip galvanized 590MPa grade dual phase steels

采用拉-拉疲劳实验研究了连续退火与连续热镀锌590MPa级冷轧双相钢的疲劳性能,绘制了它们的S-N曲线,并采用扫描电镜对其疲劳断裂特征进行了分析。结果表明,连续退火与连续热镀锌冷轧双相钢在应力比R=0.1,加载频率为15Hz的条件下的疲劳极限分别为217和216MPa,通过对疲劳试样表面的观察发现,表面铁素体/马氏体界面开裂是疲劳失效的主要原因。

S-N curves of continuous annealed and continuous hot-dip galvanized 590 MPa grade dual phase steels were drawn with tension-tension fatigue tests, and the fracture behaviors were also analyzed using scanning elec- tron microscopy. The results show that the fatigue limits of continuous annealed and continuous hovdip galvanized 590 MPa grade dual phase steels are 217 MPa and 216 MPa with loading frequency of 15 Hz and R=0.1. The sur- face observation result shows that crack initiation zones are at the boundary of ferrite and martensite on the surface of the steels.