异种钢焊接接头残余应力理论预测的基础问题研究

项目名称： 异种钢焊接接头残余应力理论预测的基础问题研究

项目编号： No.51275544

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 机械、仪表工业

项目作者： 邓德安

作者单位： 重庆大学

项目金额： 80万元

中文摘要： 以核电设备中典型结构材料奥氏体不锈钢、镍合金和低合金高强钢的焊接接头为研究对象，采用物理实验与数值模拟技术相结合的方法，对焊接残余应力理论预测的若干基础问题进行深入研究。一方面通过设计合理的实验方案，测量母材和焊缝金属的高温力学性能、固态相变相关参数和退火效应温度等，为数值模拟提供准确的材料数据。另一方面开发可变长度热源模型以及考虑加工硬化、退火效应和固态相变的先进材料模型来高效、高精度地模拟厚大焊接接头的残余应力。利用实验测量的材料数据和所开发的数值模拟方法，澄清材料的屈服强度、加工硬化、退火效应及固态相变等对焊接残余应力的影响。本项目的目标是通过数值模拟结果与实验的反复比较和验证，最终确立预测焊接残余应力的高效、高精度热-冶金-力学耦合的有限元计算方法。该数值模拟方法将是核电设备中关键焊接接头结构完整性和使用寿命评价的有效工具，同时它也能用于指导制定合理的焊接工艺和优化焊接接头设计。

中文关键词： 退火效应；热源模型；数值模拟；相变；残余应力

英文摘要： The fundamental issues on how to accurately predict welding residual stress distribution in typical weld joints used in nuclear power plants will be investigated by means of experiment and numerical simulation technology in this project. Through designing reasonable experimental methods, we will measure the temperature-dependent mechanical properties, parameters related to solid-state phase transformation and "annealing effect temperature". These measured data will be directly used in the new numerical simulation method developed by this work. To increase the computing efficiency, a new heat source model named "variable length heat source" will be proposed. Meanwhile, based on conventional thermo-elastic-plastic finite element method, an advanced material model considering work hardening rule, annealing effect and solid-state phase transformation will be developed to accurately simulate welding residual stress in similar and dissimilar metal weld joints with thick plates. Using the measured data and the developed computational approach, we will clarify the influence of yield strength, work hardening, annealing effect and solid-state phase transformation on welding residual stress distribution. Through comparing the simulation results with the residual stress values measured by experimental mock-ups time after ti

英文关键词： Annealing effect；Heat source model；Numerical simulation；Phase transformation；Residual stress