Simultaneously improved the strength dramatically and eliminated HAZ softening of DP980 steel pulsed-arc welding joints by PWHT
Simultaneously improved the strength dramatically and eliminated HAZ softening of DP980 steel pulsed-arc welding joints by PWHT
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DOI：
10.1016/j.msea.2022.142752
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发表时间：
2022-01
期刊：
影响因子：
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通讯作者：
Zhiqiang Wu;Shuai Liu;Zhibin Yang;Honggang Zhou;Eric Li;H. Pan;Y. Chen;Liwei Lu;Longfei Liu
中科院分区：
文献类型：
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作者：
Zhiqiang Wu;Shuai Liu;Zhibin Yang;Honggang Zhou;Eric Li;H. Pan;Y. Chen;Liwei Lu;Longfei Liu
提出了一种消除DP 980钢焊接接头热影响区软化、提高焊接接头强度的焊后热处理工艺。结果表明，750-950 °C高温等温转变后再进行水淬，通过改变焊接接头的显微组织，对接头的强度和断裂位置产生显著影响。焊后热处理使块状马氏体离散分布在岛状铁素体中，导致铁素体在空间上连续变形。同时，焊后热处理后接头组织更加均匀。结果表明，950 °C焊后热处理可获得最高强度（1146 MPa），约为焊态强度的1.35倍。
A pathway of post-weld heat treatment (PWHT) to eliminate heat affected zone (HAZ) softening and improve the strength of the welded joints of DP980 steel was developed. It is found that the high temperature isothermal transition at 750–950 °C followed by water-quenching significantly influences the strength and fracture location by changing the microstructures of the welded joint. The block martensite is distributed discretely in the island ferrite after PWHT, which causes ferrite to deform continuously in space. At the same time, the microstructure of joints is more uniform after PWHT. As a result, the highest strength (1146 MPa) can be obtained by PWHT at 950 °C, which is about 1.35 times that of the as-welded joint.