屈服强度失配对异种金属焊接接头裂纹扩展的影响分析

The effect analysis of yield strength mismatch on the crack propagation in dissimilar metal welded joint

为了解含缺陷核电关键构件的裂纹扩展情况,以核电一回路安全端异种金属焊接接头为研究对象,建立了符合工程实际的核电焊接接头材料模型,基于XFEM分析了屈服强度失配对裂纹扩展力学场和路径的影响。结果表明:屈服强度对裂尖力学场的梯度变化影响较小;而屈服强度的高组配形式在一定范围内能够抑制裂纹的萌生,等组配形式有利于裂纹的扩展,屈服强度的增大会使裂纹启裂所需应力值增大而裂纹扩展长度减小。研究结果为异种金属焊接接头的安全性评价提供了依据。

To understand the crack propagation of key component of nuclear power,the dissimilar metal weld joint in primary circuit was chosen as the research object,and a nuclear power welded joint material model was established based on engineering practice.The effects of yield strength mismatch on the mechanical filed and path of the crack propagation were analyzed based on the XFEM in ABAQUS.Results show that the yield strength has little effect on the gradient change of the crack tip mechanical field;the yield strength overmatch can to some extent inhibit the crack initiation,while the yield strength equal match can contribute to the crack propagation.The increase of the yield strength will enhance the resistance required for crack growth and decrease the crack propagation length.The research results can provide valuable references for the safety assessment of dissimilar metal welded joints.