Evaluation of Ductility-Dip Cracking Susceptibility in Alloy 690 Laser Multipass Weld Metal by Varestraint Test
Evaluation of Ductility-Dip Cracking Susceptibility in Alloy 690 Laser Multipass Weld Metal by Varestraint Test
复制标题
通过 Varestraint 试验评估合金 690 激光多道焊接金属的延展性-倾角裂纹敏感性
DOI：
10.2207/qjjws.34.181
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
K. Saida
中科院分区：
文献类型：
--
作者：
T. Ogura;Yusuke Morikawa;K. Saida
采用不同P、S含量的钎料对690铝合金激光多道焊焊缝金属的延性-浸渍裂纹敏感性进行了定量评价。为了在激光多道焊焊缝金属中合成一个塑性下降裂纹，在不同的焊接速度下进行了激光焊接的跨焊道横向变约束试验。随着焊缝金属中P和S含量的增加，焊缝金属的延性-浸渍温度范围（DTR）增大，且S比P更能有效地提高DTR;随着焊接速度的增加，DTR减小。P和S的晶界偏聚的数值模拟表明，P和S在晶界的偏聚浓度增加的P和S在焊缝金属中的含量的增加，而这些略有下降，由于快速加热和冷却速度的焊接速度的增加。结果表明，激光多道焊过程中P和S的晶界偏聚行为与焊缝的塑性-浸渍裂纹敏感性随钎料成分和焊接速度的变化规律一致。根据DTR的回归分析，将晶界偏聚浓度（P+2.42S）降低到小于
Ductility-dip cracking susceptibility in the laser multipass weld metal of alloy 690 was quantitatively evaluated using different filler metals varying the contents of P and S. In order to synthesize a ductility-dip crack in the laser multipass weld metal, the cross-bead longitudinal-Varestraint test with laser welding was applied under the various welding speed. The ductility-dip temperature range (DTR) was increased with an increase in P and S contents in the weld metal, and S was more effective to enhancing the DTR compared with P. Furthermore, the DTR was decreased with an increase in the welding speed. A numerical simulation of grain boundary segregation of P and S revealed that the segregated concentrations of P and S at grain boundaries were increased with an increase in the P and S contents in the weld metal, and that those were slightly decreased with an increase in the welding speed due to the rapid heating and cooling rates. It follows that the changes in ductility-dip cracking susceptibility with the filler metal composition and welding speed were consistent with the grain boundary segregation behaviours of P and S during laser multipass welding process. According to the regression analysis of the DTR, ductility-dip cracking in the laser multipass weld metal would be inhibited by reducing the segregated concentration at grain boundary (P+2.42S) to less than