低碳钢高温相变对焊接角变形的影响

Effect of high-temperature phase transition of low carbon steel on weld angular distortion

低碳钢板具有良好的综合力学性能和焊接性能,被广泛地应用在各种焊接结构中,但是对接接头角变形一直是焊接过程中的突出问题.文中通过测试低碳钢对接接头动态角变形,对其变化过程和特点进行了分析和总结.结果表明,除温度变化引起的体积线性变化对角变形产生影响外,700℃以上温度发生的高温相变对自由状态下单层对接接头焊缝以及多层多道焊的首层焊缝角变形变化将产生影响;而多层焊接除首层以外的其它层焊缝,700℃以上温度的相变将对角变形变化不产生影响.

For its good mechanical properties and weld ability, low carbon structural steel is widely used in a variety of welded structure. The angular distortion is a serious problem to be resolved in the butt joint welding process. The angle distortion changes in multiplayer welding butt joint of Q235 low carbon steel plate are measured, and the angle changing process and characteristics of deformation of the joint are analyzed and summarized. The results show that linear variation in volume with temperature variation has an effect on angular distortion. In addition, high-temperature phase transformation above 700 ℃ will affect the angular distortion of single-layer weld and the root weld of multi-layer and multi-pass welding but has less effect on that of the multi-layer welding except the root weld of multi-layer welding.