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    热输入对低温高锰钢焊接接头组织和性能的影响

    Effect of Welding Heat Input on Microstructure and Properties of Welded Joint of Low Temperature High Manganese Steel

    • 摘要: 采用CHW-SMn埋弧焊丝并配套CHF610焊剂,在不同热输入(12.0,16.0,20.0 kJ•cm−1)下对低温高锰钢进行埋弧焊焊接,研究了热输入对接头显微组织和性能的影响。结果表明:3种热输入下焊缝组织由柱状晶+析出相组成,热影响区组织为奥氏体和少量夹杂物;热影响区组织粗化,粗晶区宽度增加。随着热输入增大,低温高锰钢焊接接头强度和韧性下降,焊缝显微硬度先降后升,当热输入为12.0,16.0 kJ•cm−1时弯曲后焊缝表面未观察到裂纹,当热输入为20.0 kJ•cm−1时出现裂纹;不同热输入下接头的拉伸断口和冲击断口均呈韧窝形貌,断裂方式为韧性断裂,当热输入为12 kJ•cm−1时,焊接接头力学性能较优。

       

      Abstract: CHW-SMn submerged arc welding wire with CHF610 flux was used to perform submerged arc welding on low temperature high manganese steel under different heat inputs (12.0, 16.0, 20.0 kJ•cm−1), and the effect of heat input on the microstructure and properties of the joint was studied. The results show that under three different heat inputs, the weld microstructure was composed of columnar crystal + precipitate, and the microstructure of the heat affected zone was austenite with a small amount of inclusions. The omicrostructure of the heat affected zone was coarsened and the width of the coarse crystal zone was increased. With the increase of heat input, the strength and toughness of the welded joint of low temperature and high manganese steel decreased, and the microhardness of the weld decreased first and then increased. When the heat input was 12.0 kJ•cm−1 and 16.0 kJ•cm−1, no cracks were observed on the surface of the bent weld, but cracks appeared when the heat input was 20.0 kJ•cm−1; The tensile and impact fracture of the joint under different heat inputs were dimpled, and the fracture mode was ductile fracture. When the heat input was 12.0 kJ•cm−1, the mechanical properties of the welded joint were better.

       

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