论文部分内容阅读
采用阴极充H、恒载荷拉伸和电化学H渗透等试验方法,研究了超高强度钢22MnB5Nb的H扩散行为及氢致滞后开裂性能,并与常用热冲压钢22MnB5进行了对比。结果表明,H在22MnB5Nb钢中的扩散系数为3.02×10-7 cm2/s,显著低于22MnB5钢;与22MnB5钢相比,22MnB5Nb钢具有较好的耐氢致滞后开裂性能;这是由于22MnB5Nb钢晶粒较细小,增加了晶界的有效面积,使H陷阱分布更均匀,进而抑制H向裂纹尖端扩展,避免了局部H的富集。
H diffusion behavior and hydrogen induced hysteresis cracking behavior of ultra-high strength steel 22MnB5Nb were investigated by means of cathode charge H, tensile test at constant load and electrochemical H permeation. The results were compared with that of 22MnB5 hot-stamped steel. The results show that the diffusion coefficient of H in 22MnB5Nb steel is 3.02 × 10-7 cm2 / s, which is significantly lower than that of 22MnB5 steel. Compared with 22MnB5 steel, 22MnB5Nb steel has better resistance to hydrogen induced hysteresis cracking. This is because 22MnB5Nb The grain size of the steel is smaller and the effective area of the grain boundary is increased, so that the distribution of the H traps is more uniform, thereby suppressing the propagation of the H-direction crack tip and avoiding the enrichment of the local H.