焊接工艺对690镍基合金焊丝熔敷金属高温失塑裂纹敏感性影响研究

Research on influence of welding technology on DDC susceptibility of deposited metal of 690 nickel base alloy welding wires at high temperature

针对690镍基合金熔敷金属高温失塑裂纹敏感性问题,采用基于Gleeble-3500热力耦合试验机的STF试验,开展焊接工艺对国产化690镍基合金焊丝WHS690M熔敷金属高温失塑裂纹敏感性的影响研究,并与进口Inconel 52M焊丝试验结果进行对比分析。试验表明,熔敷金属高温失塑裂纹最小临界应变出现在1 050℃附近,焊接热输入对最小临界应变影响较小,相比于大面积堆焊熔敷层,对接焊缝熔敷金属临界应变降低,高温失塑裂纹敏感性提高。

For the problems of the ductility dip cracking(DDC) susceptibility of deposited metal of 690 nickel base alloy at high tempe-rature,a strain-to-fracture(STF) test based on Gleeble-3500 thermo-mechanical simulator is performed to evaluate the DDC susceptibility of WHS690M and Inconel 52M. The results show that the minimum critical strain of the DDC of deposited metal appears at the temperature about 1 050 ℃,and welding heat input has little effect on the minimum critical strain. Comparing with the deposited layer of large-area surfacing,the critical strain of butt weld deposited metal reduces,and DDC susceptibility increases.