晶粒取向对双晶模型氢扩散的影响

Effect of grain orientation on hydrogen diffusion in twin crystal model

奥氏体不锈钢长期服役于氢环境会产生氢脆,引起结构安全隐患;氢的扩散与材料晶界倾角和晶粒取向密切相关,尤其是氢扩散和晶粒取向之间的关系还未被很好地解释。针对上述问题,提出利用ABAQUS软件建立有限元模型,将奥氏体不锈钢各向异性行为和氢扩散进行耦合,以考虑晶粒取向对双晶模型氢扩散的影响,并研究3种不同晶粒取向组成的双晶模型。结果表明:晶界附近区域的应力集中由晶粒取向不同导致;应力对氢扩散有促进作用;晶粒取向与晶粒尺寸大小无关。

Long term service of austenitic stainless steel in hydrogen environment produces hydrogen embrittlement and causes potential structural safety hazards;Hydrogen diffusion is closely related to grain boundary inclination and grain orientation,especially the relationship between hydrogen diffusion and grain orientation had not been well explained.To solve the above problems,a finite element model was established by using ABAQUS software to couple the anisotropic behavior of austenitic stainless steel and hydrogen diffusion,so as to consider the effect of grain orientation on hydrogen diffusion of bicrystal model,and study the bicrystal model composed of three different grain orientations.The results show that the stress concentration near the grain boundary is caused by different grain orientation;Stress can promote hydrogen diffusion;Grain orientation is independent of grain size.