冷轧双相超高强钢氢致延迟断裂门槛应力研究

Threshold stress of hydrogen-induced delayed fracture for high strength cold-rolled dual phase steel

以抗拉强度为1 000 MPa级的汽车用冷轧双相钢为对象,采用电化学充氢和恒载荷拉伸试验方法,研究了材料在不同应力和充氢条件下的延迟断裂行为以及材料延迟断裂门槛应力与氢浓度之间的关系。结果表明,在充氢条件下材料延迟断裂时间随着应力的增大而缩短,延迟断裂的门槛应力随着充氢电流密度增大而下降,延迟断裂门槛应力与临界可扩散氢浓度的对数呈线性关系。

The hydrogen-induced delayed fracture behavior of high strength cold-rolled dual phase steel was studied using electrochemical hydrogen charging and constant load test, the threshold stress and the relationship between the stress and the hydrogen content were investigated. The results showed that the time to delayed fracture reduced with the increase of the applied load, the threshold stress declined with the increase of charging current density, and the threshold stress is linear relationship with the natural logarithm of the critical diffusible hydrogen content.