• CN:11-2187/TH
  • ISSN:0577-6686

机械工程学报

• 搅拌摩擦焊接专栏 • 上一篇    下一篇

焊后热处理对高氮奥氏体不锈钢搅拌摩擦焊接头组织及性能的影响

李艺君1, 2,  杜东旭1, 2,  付瑞东1, 2,    

  1. 1. 燕山大学亚稳材料科学与技术国家重点实验室  秦皇岛  066004;
    2. 燕山大学材料科学与工程学院  秦皇岛  066004
  • 收稿日期:2015-05-06 修回日期:2015-08-10 出版日期:2015-11-15 发布日期:2015-11-15
  • 通讯作者: 付瑞东,男,1968年出生,博士,教授,博士研究生导师。主要研究方向为搅拌摩擦焊接及加工,金属热塑性变形和金属强韧化。 E-mail:rdfu@ysu.edu.cn
  • 作者简介:李艺君,男,1987年出生,博士研究生。主要研究方向为高熔点金属搅拌摩擦焊接及加工。 E-mail:liyijun1987@126.com
  • 基金资助:
    河北省自然科学基金资助项目(E2013203370)

 Effect of Post-welded Heat Treatment on the Microstructures and Mechanical Properties of Friction Stir Welded Joint of High-nitrogen Austenitic Stainless Steel

LI Yijun1, 2,  DU Dongxu1, 2,  FU Ruidong1, 2   

  1. 1. State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004;
    2. College of Materials Science and Engineering, Yanshan University, Qinhuangdao 066004
  • Received:2015-05-06 Revised:2015-08-10 Online:2015-11-15 Published:2015-11-15

摘要: 对高氮奥氏体不锈钢进行搅拌摩擦焊接。焊接过程中没有出现氮元素的损失及其他相的生成。对焊接接头进行焊后热处理,以得到具有不同组织差异性的搅拌摩擦焊接头。微观组织分析表明:在焊态的接头中,焊核区晶粒细化且含有大量的小角度晶界,母材区与焊核之间存在明显的组织差异;热处理态接头中,焊核区的晶粒尺寸略小于母材,各种特征晶界的比例分数都与母材基本相当,接头内组织差异性减小。力学性能分析表明:大的组织差异使焊接接头呈现出典型的高匹配特征,屈服强度、抗拉强度明显升高,伸长率有所降低。较小组织差异的接头匹配模式发生变化,进而导致力学性能发生明显改变,屈服强度、抗拉强度降低,伸长率恢复到母材水平。

关键词: 高氮奥氏体不锈钢, 焊后热处理, 搅拌摩擦焊接, 强度匹配, 组织差异

Abstract: Friction stir welding is applied to a high-nitrogen austenitic stainless steel. Loss of nitrogen and other precipitates are not found during the process of friction stir welding. In the as-welded joint, the nugget zone is consisted of fine grains with high fraction of low angle boundaries. Significant differences of microstructure are observed along the transverse direction of as-welded joint. Further, the post-weld heat treatment joint is shown an effectively weaken difference. The differences of microstructure have a significant impact to the mechanical property. In the as-welded, the distribution of different microstructures leads to overmatching characteristic with higher strength but lower ductile. In the post-weld heat treatment joint, the strength matching mode is changed. The elongation of the joint is increased companied with enhanced strength.

 

Key words: differences of microstructure, friction stir welding, high-nitrogen austenitic stainless steel, post-weld heat treatment, strength matching