摘要
为了降低镍基高温合金焊缝的热裂纹敏感性,采用在TIG焊过程中施加横向和纵向低频机械振动的方式进行焊接试验,焊后采用光学显微镜和扫描电子显微镜分析焊缝的微观组织以及析出相的变化特征,并对焊接接头的显微硬度进行了对比分析。试验结果表明:不同的振动方式下焊缝晶粒的细化效果不同,与横向振动相比,施加纵向振动的焊缝可以获得细小均匀的等轴晶组织,焊接接头的显微硬度明显提高。与常规焊接相比,不管是施加横向振动还是纵向振动,焊缝处的γ′相更加细小,且弥散均匀分布。因此,焊接过程中施加低频机械振动有利于降低镍基高温合金焊缝的热裂纹敏感性。
In order to reduce the hot cracking susceptibility of nickel-base alloys weld, the welding experiment was carried out by applying the transverse and longitudinal low-frequency mechanical vibration during the TIG welding process. The microstructure and precipitation phase of the weld were characterized by optical microscope and scanning electron microscope, and the microhardness of welding joints were analyzed after welding. The results showed that the grain refinement effect of weld was dissimilar under different vibration modes. Compared with transverse vibration, the weld with longitudinal vibration could achieve fine and uniform equiaxed grain, and the microhardness of welded joint was enhanced significantly. Compared with the conventional welding, no matter applied transverse vibration or longitudinal vibration, γ′ phase was finer and dispersive distribution. Therefore, applying low-frequency mechanical vibration during the welding process could be beneficial to reduce the hot cracking susceptibility of nickel-base alloys weld.
出处
《焊接技术》
2018年第8期52-55,共4页
Welding Technology
关键词
机械振动
镍基高温合金
晶粒细化
热裂纹
mechanical vibration
nickel-base alloys
grain refinement
hot cracking
