基于超声振动的304不锈钢TIG焊接

TIG welding of the stainless steel 304 based on the ultrasonic vibration

304不锈钢是应用最为广泛的一种奥氏体不锈钢,它具有优良的耐蚀性和耐热性,优良的低温强度和力学性能.304不锈钢常用的焊接方法为TIG焊接.普通TIG焊接由于焊缝熔深浅、焊接速度低、焊接效率较低,而且在焊接过程中容易出现焊缝区和热影响区的晶粒粗大,造成焊接接头质量下降.功率超声振动是金属凝固过程中改善组织、提高力学性能的有效方法之一.为了提高焊接效率和改进接头的质量,将超声振动通过机械耦合方式引入304不锈钢TIG焊接的过程中,进行了平板堆焊试验.结果表明,施加超声后焊接的熔深有效增加,深宽比增大,焊缝结晶方式由粗大柱状晶转变为细小的树枝晶和等轴晶,晶粒度减小,熔合区组织均匀化.

Stainless steel 304 is one sort of the austenitic stainless steel for most extensive use.It has excellent corrosion resisting and fire resisting property,high hypothermic strength and fine mechanical property.Its welding method is TIG in common use.The TIG welding method is an inefficient welding method because of its shallow penetration and low welding speed,the grain size of the weld is also inclined to grow up which may reduce the performance of the weld.Ultrasonic treatment is an effective way to minimize the grain size and improve the microstructure in the process of metal freezing.Ultrasonic treatment was lead in the process of TIG welding of stainless steel 304 to increase the welding efficiency and improve the weld property.Build-up welding experiments were taken on the flat plate.The results showed that the weld penetration and depth-to-width ratio increase and the crystallizing mode change from columnar crystals to small dentrite equiaxed crystals.Also,the grain size reduce and the organization of the fusion area is uniformed.