镍基合金焊缝金属热裂纹及接头强韧性的研究进展

综述了镍基合金焊缝金属在热裂纹及接头强韧性方面的最新研究进展,得出:1)焊丝中添加Nb、Al、Ti、Ce等合金元素可降低焊缝金属高温失塑裂纹敏感性,添加Mn和Mg可抑制S、P、Si、Bi等低熔点化合物的生成,控制药芯组成中TiO2、SiO2、ZrO2、MnO2等造渣剂之间比例关系,有助于提高焊缝金属抗热裂纹性;2)采用合适的焊接工艺可有效避免焊缝金属热裂纹的产生,其中,激光焊、电子束焊等新型焊接工艺对焊缝金属热裂纹的影响逐渐成为研究热点;3)采用固溶+双级时效的焊后热处理工艺,可改善焊接接头的强韧性,焊丝中添加Al、Ti、Nb、Mo、Mn等合金元素可提高焊接接头抗拉强度,但随着Mn质量分数的增加,接头冲击韧性降低.

Progress of Hot Cracking of Weld Metal and Strength & Toughness of Weld Joint for Nickel-based Alloy

The progress of the hot cracking of weld metal and strength & toughness of weld joint for nickel-based alloy was reviewed in this paper. It concludes that 1 ) the susceptibility of ductility-dip cracking to weld metal can be decreased by adding Nb, Al, Ti and Ce alloying elements in filler wire. The formation of S, P, Si, Bi low melting point compounds can be prevented by adding Mn and Mg. Besides, the cracking resistance of weld metal can be improved by controlling the ratio of TiO2 , SiO2 , ZrO2 and MnO2 slagging agentsin the flux;2) by adopting appropriate welding process, the hot cracking of weld metal can be effectively avoided. The influence of new welding process, such as laser beam welding and electron beam welding, to the hot cracking of weld metal will be the hitissue of future study;3) using the post weld heat treatment of solid solution and double aging, the strength and toughness of weld joint can beimproved significantly. The tensile strength of weld joint can beimproved by adding Al, Ti,Nb,Mo and Mnin filler. However, theimpact toughness of weld joint will be decreased with the mass fraction of Mn increased in the filler wire.