蠕变性能失配对应力腐蚀裂尖力学场的影响

Effect of Creep Property Mismatch on Mechanical Field at Crack Tip of Stress Corrosion Cracking

核电一回路中应力腐蚀开裂(SCC)是奥氏体不锈钢和镍基合金的主要失效形式。金属在高温水中会发生蠕变,从而影响了裂纹的扩展速率。以紧凑拉伸试样为研究对象,采用ABAQUS软件,分析了蠕变失配对SCC裂尖应力、应变以及蠕变速率和裂纹扩展速率的影响。结果表明,蠕变会使裂尖处的高应力在短时间内快速减少,但对应变的影响不明显。随着失配比的增加,C_t积分增大,同时裂纹扩展速率也越大,裂纹在蠕变主导下更易扩展。

Stress corrosion cracking （SCC） is the main failure mode of anstenitic stainless steel and nickel based alloy in nuclear power station primary loop. The metals generate creep in high temperature water, which can affect the spreading rate of the crack. Taking compact tension specimens as research object, the effects of creep mismatch on the stress and strain at crack tip of SCC and creep rate and crack spreading rate were analyzed by using ABAQUS software. The results show that the creep can make the high stress at crack tip decrease sharply in a short time, which have little influence on the strain. With the increase of mismatch ratio, Ct-integral increases, the crack spreading rate increases, and the crack is easily to grow, which is induced by the effect of creep.