纳秒脉冲激光冲击焊接接头抗应力腐蚀机理研究

项目名称： 纳秒脉冲激光冲击焊接接头抗应力腐蚀机理研究

项目编号： No.51305456

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 机械、仪表工业

项目作者： 李玉琴

作者单位： 中国人民解放军空军工程大学

项目金额： 25万元

中文摘要： 应力腐蚀开裂问题是航空焊件常见的主要破坏形式之一，严重影响其安全可靠性，纳米脉冲激光冲击强化是近年来国外发展起来的一种新型有效的抗应力腐蚀技术，但是其核心技术对外封锁，国内开展了一些研究，但由于没有掌握这种方法形成的与焊接过程形成的残余应力场的耦合、焊缝区形成的残余应力的分布规律及其对应力腐蚀的影响，难以实现工艺上的控制，从而无法掌握这门技术。本申请项目拟以航空合金钢焊接接头为研究对象，研究焊接接头材料在激光冲击强化处理后的残余压应力场的分布规律及其优化，研究激光冲击作用下焊区组织的演化，以及焊区激光冲击强化产生的应力分布和微观组织共同作用影响应力腐蚀的机理。实现激光冲击波作用下的应力腐蚀控制，为激光冲击强化技术的应用于解决焊接接头应力腐蚀问题提供理论分析和数据支持。

中文关键词： 纳秒脉冲激光冲击强化；焊接接头；残余应力；微观组织；应力腐蚀

英文摘要： Stress corrosion crack is one of the major damages during the aeronautical weldment which severely affect its reliability and safety. Nano-pulse laser shock peening is a new effective stress corrosion resistance technology developed by foreign countries in recent years. The core of the technology is blocked to foreign countries. Some researches on it have been conducted in china, but without the couple of the residual stress field , the distribution of the residual stress near the weld head and its influence on the stress corrosion, it is difficult to carry out the process control. Aeronautical alloy steel welding joint is used as the research sample in this project. The focuses of the research are as follows: The distribution of the residual stress field and optimization on the weld joint after peenging by the laser shock; the evolution of the weld area microstructure after laser shock; the mechanism of the influence by the microstructure and residual stress on the stress corrosion. The research is to control the stress corrosion under the laser shock，and provide theoretical analysis and supporting data to solve the welding joint stress corrosion.

英文关键词： nanosecond Pulse Laser Shock Peening；welded Joint；residual stresses；microstructure； stress corrosion