一般认为裂纹材料的氢脆开裂是一个和氢原子扩散有关的过程。在负载条件下,氢原子将从四周扩散到裂纹尖端高应力区,当局部浓度达到临界值即起始开裂。开裂的每一步只能跃进一定距离,当裂纹扩展到氢含量很低的区域便暂时停止,然后,氢原子又再扩散聚集,如此往复,裂纹以不连续开裂方式向前扩展。 Hydrogen embrittlement cracking is generally believed to be a process associated with hydrogen atom diffusion. Under load conditions, hydrogen atoms will diffuse from the periphery to the high-stress zone of the crack tip. When the local concentration reaches the critical value, the initial cracking will occur. Each step of cracking can only leap forward a certain distance. When the crack expands to a region with low hydrogen content, it stops temporarily. Then, the hydrogen atoms are diffused and aggregated again. In this way, the crack expands discontinuously.