高温水环境中镍基合金力学性能对裂尖力学化学效应的影响

Influence of Nickel-based Alloys Mechanical Properties on Mechanochemical Effect at Crack Tip in High Temperature Water Envir

摘要:

力学与化学相互作用引起的力学化学效应会加速核电站中镍基合金的应力腐蚀开裂行为。焊接接头材料力学性能的不均匀性，将间接影响材料的力学化学效应。本文采用标准紧凑拉伸试样和有限元方法，研究得到了高温水环境中600合金屈服强度和硬化指数对裂纹尖端表面力学化学效应的影响，分析了弹性和塑性变形对裂纹尖端力学化学效应的作用。结果表明600合金裂尖表面的力学化学效应受到屈服强度的变化的影响，但硬化指数对裂尖表面力学化学效应的影响不明显。

Abstract:

Mechanochemical effect which is the interaction of mechanical and chemical can accelerate the stress corrosion cracking (SCC) in nickel-based used in nuclear power plants. The mechanical properties heterogeneity in weld joints will influence the mechanochemical effect indirectly. The effects of yield strength and hardening exponent of alloy 600 on the mechanochemical effect of crack tip surface in high temperature water environment were studied by adopting one inch compact tension specimen and finite element method. The effects of elastic and plastic deformation on the change of mechanochemical effect were discussed. The results indicate that the mechanochemical effect is affected by the yield strength. In contrary, the hardening exponent change of alloy 600 has insignificantly influence on mechanochemical effect.