热处理对MGH956合金TIG原位合金化焊接的焊缝组织的影响

Effects of heat treatment on TIG in situ alloying welded MGH956 alloys microstructure

MGH956合金TIG原位合金化焊接后焊缝中合金元素易烧损,强化颗粒易聚集,研究了一种热处理方法对焊缝的组织的影响。焊接填充材料的ωV=2.0%,热处理条件为700℃保温2h后空冷。焊缝热处理后,晶界上的偏聚明显减少,在晶粒内部生成更多的细小弥散分布的颗粒,EDS分析主要为YAlO3、TiC和TiN颗粒,此外还有(Ti,V)C复合颗粒,由于VC比TiC与铁基的润湿角更小,复合颗粒与焊缝基体结合更好。通过原子探针分析,热处理后,焊缝中Y元素的偏聚减少,进而减少焊缝的气孔量,最终提高焊缝的性能。

It was easy for alloying elements and strengthening particles in MGH956 alloy to burning and aggrega-ting during TIG in -situ welding.In this paper,effects of heat treatment on MGH 956 alloys microstructure TIG in-situ alloying welded were studied.Filler material of ωV =2.0% was used in the welding process,heat preservation time was 2.0 h,temperature was 700 ℃,and then air cooling.After heat treated,the grain bound-ary aggregation was significantly reduced,more fine particles generated in the weld,which were mainly YA-lO 3 ,TiC and TiN particle demonstrated by EDS analysis,in addition,（Ti,V）C composite particles were fund. By atomic probe analysis,the segregation of element Y reduced,therefore the porosity of the weld were reduced after heat treatment,ultimately,performance of the joint was improved.