机械振动对激光焊接接头组织的影响

发布时间：2018-02-17 05:40

本文关键词： 机械振动激光焊接微观组织　出处：《机械工程学报》2015年20期 　论文类型：期刊论文

【摘要】：振动焊接工艺能有效细化接头组织晶粒,降低残余应力,提高焊接质量。为了研究振动焊接工艺在激光焊接方面的应用,选用316不锈钢作为试验材料,利用机械振动辅助激光焊接的工艺方法,通过改变机械振动参数和焊接速度,利用光学显微镜和扫描电镜观察焊后接头组织,对比分析不同振动频率和焊接速度下接头的微观组织形貌。结果表明,机械振动可以细化焊后组织中形成的柱状晶,使柱状枝晶破碎且向不同方向生长,晶轴间与焊缝中心处的等轴晶增加。提高焊接速度后,振动的加入能够细化焊缝区出现的粗大柱状晶。同时,振动可以减少焊后在奥氏体基体晶界处形成的网状高温铁素体和点状碳化物,使其趋于弥散。试验还对焊接接头进行显微硬度测试,发现振动焊接下得到的焊缝区接头组织硬度较高,且较高共振频率下硬度增加明显。
[Abstract]:In order to study the application of vibration welding technology in laser welding, 316 stainless steel is selected as the test material. By changing mechanical vibration parameters and welding speed, the microstructure of welded joints was observed by optical microscope and scanning electron microscope. The results show that mechanical vibration can refine the columnar crystal formed in the welded structure, and make the columnar dendrite break up and grow in different directions. The equiaxed crystal between the axis and the center of the weld increases. When the welding speed is increased, the addition of vibration can refine the coarse columnar crystal appearing in the weld zone. At the same time, Vibration can reduce the formation of netted high temperature ferrite and point carbide at the grain boundary of austenitic matrix after welding and make them disperse. The microhardness of welded joints is also tested. It is found that the microstructure hardness of welded joints obtained by vibration welding is higher and the hardness increases obviously at higher resonance frequency.
【作者单位】：上海工程技术大学材料工程学院;上海工程技术大学上海市高强激光智能加工装备关键技术产学研开发中心;
【基金】：国家自然科学基金资助项目(51305253)
【分类号】：TG456.7;TG407

【参考文献】