活性剂对GH4169高温合金激光焊接头组织及性能的影响

Effects of Active Flux on Microstructure and Properties of Laser Welding Joint of Superalloy GH4169

采用自行研制的活性剂对GH4169进行活性剂激光焊接试验,研究了活性剂对焊缝深宽比、焊缝元素分布、微观组织结构以及力学性能的影响规律。结果表明:采用活性剂进行激光焊接后,焊缝深宽比显著增加,活性剂对焊缝元素含量和物相组成基本没有影响。表面涂敷活性剂后,焊缝中的显微组织仍是由靠近熔合线附近的柱状晶区和焊缝中心的等轴晶区组成,但焊缝等轴晶区变大、晶粒发生细化。涂敷活性剂后焊缝中心区的显微硬度增加,但焊接接头塑性显著下降,接头的抗拉强度可达927.4 MPa,为GH4169母材强度的93%。

Laser welding tests of GH4169 plates with self-developed active flux were carried out, and the effects of activeflux on depth to width ratio, element distribution, microstructure and mechanical properties of the weld were studied. Theresults show that after laser welding with active flux, the weld depth to width ratio increases significantly, but the active fluxhas no effect on element distribution and phase composition of the weld. After coating the surface with active flux, themicrostructure of the weld is still composed of columnar crystal zone near the fusion line and equiaxed grain zone of the weldcenter, however the equiaxed grain zone of the weld is enlarged and the grain is refined. The micro-hardness of the weldcenter increases, but the plasticity of the joint significantly decreases. The tensile strength of the joint can reach 927.4MPa,which is up to 93% of the base metal.