Microstructural and Mechanical Characterization of Dissimilar Metal Welding of Inconel 625 and AISI 316L
Microstructural and Mechanical Characterization of Dissimilar Metal Welding of Inconel 625 and AISI 316L
复制标题
Inconel 625 和 AISI 316L 异种金属焊接的微观结构和机械表征
作者：
Fatih Dokme;M. K. Kulekci;Uğur Eşme
研究了Inconel 625和AISI 316L异种金属焊接的显微组织，采用连续电流钨极氩弧焊（CCGTAW）和脉冲电流钨极氩弧焊（PCGTAW）工艺，使用ERNiCr-3、TIG 316L和扭曲（ERNiCr-3和TIG 316L）填料。使用光学显微镜和扫描电子显微镜（SEM）/能量色散X射线（EDAX）进行微观结构检查。研究结果表明，在AISI 316 L侧存在部分熔化区（PMZ）。焊接区（WZ）分析表明，在所有试样的316 L侧的多方向晶粒生长的存在，虽然较少的增长被发现在Inconel 625侧。使用扭曲填料的PCGTAW，晶粒长大几乎消失。SEM/EDAX研究表明，在五个实验中，第二有害第二相是细小的白色。然而，少量的析出物发生在PCGTA焊接扭曲填料。此外，这些是特别无害的沉淀物，在图像中由黑点表示，而其他微小的白色第二相已知是脆性的。结果表明，采用扭曲填料的PCGTA焊接具有最佳的冶金性能。
This study investigated the microstructure of the dissimilar metal welding of Inconel 625 and AISI 316L using Continuous Current Gas Tungsten Arc Welding (CCGTAW) and Pulsed Current Gas Tungsten Arc Welding (PCGTAW) processes with ERNiCr-3, TIG 316L and twisted (ERNiCr-3 and TIG 316L) fillers. Microstructure examinations were carried out using an optical microscope and Scanning Electron Microscopy (SEM)/Energy Dispersive X-Ray (EDAX). The results of the study showed the existence of a partially melted zone (PMZ) on the AISI 316L side. Weld zone (WZ) analysis showed the existence of a multi-directional grain growth on the 316L side in all specimens, although less growth was found on the Inconel 625 side. Grain growth almost disappeared using PCGTAW with twisted fillers. SEM/EDAX investigations indicated that secondary deleterious secondary phases were tiny and white in five experiments. However, a meager amount of precipitates occurred in PCGTA welding with twisted fillers. Moreover, these were particularly innocent precipitates, represented by black dots in images, whereas other tiny white secondary phases are known to be brittle. As a result, PCGTA welding with twisted fillers exhibited the best metallurgical properties.