岩石亚临界裂纹扩展的应力腐蚀

Testing Study of Stress Corrosion of the Rock Subcritical Crack Growth

介绍了岩石亚临界裂纹扩展的应力腐蚀机理,采用双扭试件常位移松弛法,对金川矿区的三种岩样进行亚临界裂纹扩展速率测试,得出了应力强度因子与亚临界裂纹扩展速率间的关系。实验数据按腐蚀理论进行线性回归分析,线性相关系数较高。所测岩样的应力腐蚀亚临界裂纹扩展是拉应力和裂纹尖端物质与环境中的腐蚀介质发生化学反应,使化学键断裂这两种机制联合作用的结果。

First the stress corrosion mechanism of the rock subcritical crack growth was introduced. And then the constant-displacement-relax method of double torsion specimens was applied to study subcritical crack growth of three kinds of rock samples coming from Jinchuan mine （the ore, the marble and the migmatite）. The relations between stress intensity factor and subcriti- cal crack growth velocity were analyzed. According to the corrosion theory the linearity regression analysis was carried on the experimental data. The multiple correlation coefficients were upper. And the stress corrosion theory commendably interpreted the experimental result. Two kinds of mechanisms combined to result in the stress corrosion of the subcritical crack growth of the measured rock samples. One was the tensile stress, and the other was crick tip matter which reacted with the environmental corrosive medium to cause the chemical bond break.