轻水堆关键焊接接头环境致裂机理与残余寿命预测方法

项目名称： 轻水堆关键焊接接头环境致裂机理与残余寿命预测方法

项目编号： No.51475362

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 机械、仪表工业

项目作者： 薛河

作者单位： 西安科技大学

项目金额： 83万元

中文摘要： 针对轻水堆焊接接头及材料环境致裂(EAC)影响核电设备长期安全运行这一关键工程问题，本项目拟通过探索核电高温水环境中焊接接头非均质材料、残余应力及水化学交互作用下的EAC行为机制及影响因素，研究建立轻水堆关键焊接接头EAC裂纹扩展历程和残余寿命的评价和预测方法。主要研究包括：1)裂尖微观力学参量在EAC裂尖氧化膜破裂、电化学阳极反应到氧化膜再生成反复循环过程中的作用；2)基于氧化膜破裂理论的高温水环境中不锈钢与镍基合金EAC扩展速率预测模型及主要参量解析；3) EAC裂纹扩展所引起的残余应力释放与再分布的机理及对裂尖微观力学场的影响；4)焊接接头材料力学性能不均匀性和残余应力交互作用下的轻水堆关键焊接接头EAC裂纹扩展历程预测模型。项目立足于解决核电站安全运行与监管中的科学问题，涉及到环境、材料及力学因素对焊接接头EAC的交互作用，为轻水堆关键焊接接头的全寿命设计及安全性评价提供科学依据。

中文关键词： 焊接接头；环境致裂；寿命预测；力学性能不均匀性；残余应力

英文摘要： Because it is one of the key engineering problems affecting the long-term safe operation of nuclear power equipment that environmentally assisted cracking (EAC) of welded structure materials in light water reactors, the EAC behavior and mechanism and related factors in welded joints under the interactive effect of inhomogeneous materials, residual stress and water chemistry in the high temperature aqueous environmental of nuclear power plant will be investigated in the proposal, which is for obtaining prediction approach and accurate evaluation of EAC crack growing process and residual life of welded joints in light water reactor. The main study included: 1) The action of the micro mechanical parameters at the growing tip of EAC crack on the repeated cycle process will be investigated, which is from the oxide film rupture, to electrochemical anodic reaction, and to oxide film reform; 2) The prediction model of EAC growth rate and the related parameters of various austenite stainless steel and nickel base alloys in high temperature water environment will be analyzed; 3) Mechanism of release and redistribution of the welded residual stress induced by EAC growing and its effects on micro mechanical field at the tip of EAC will be investigated; 4) The predicting model of EAC growth rate of the critical welded joints in light water reactor under the interactive effect of residual stress and mechanical inhomogeneity will be established. Based on solving the scientific issues in the safe operation and regulatory of nuclear power plants, the cross action of the environment, materials and mechanical factors on the EAC in welded joints is considered and investigated, which provide a scientific basis for life design and the safety evaluation of the critical welded structure in light water reactor.

英文关键词： Welded joint;Environmentally assisted cracking;Life prediction;Mechanical heteogeneity;Residual stress