淬火应力引起的车轮钢焊接裂纹研究

Research on Welding Cracks in Wheel Steel Caused by Quenching Stress

对出现焊接裂纹的车轮钢裂纹处进行微观结构分析、能谱分析,检测结果显示,焊接热影响区晶粒长大严重,且焊接后焊缝位置从高温急冷至室温,冷却速率较快,产生了较大的淬火应力,最终在焊缝位置处产生较大面积的晶粒裂纹,导致焊接开裂。用户制作轮辋焊接工艺结束后,设定焊接电流范围为7800~9500 A、顶锻时间为0.2 s,并对焊缝位置进行空冷或者缓冷,大大提高了车轮钢产品焊接质量,降低了焊接裂纹产生的几率。

Microstructural analysis and energy spectrum analysis were conducted on the cracks in the wheel steel where welding cracks occurred.The detection results showed that the grain growth in the welding heat affected zone was severe,and the welding seam position was rapidly cooled from high temperature to room temperature after welding,with a fast cooling rate,resulting in significant quenching stress.Finally,a large area of grain cracks was generated at the welding seam position,leading to welding cracks.After the user completes the wheel rim welding process,the welding current range is set to 7800~9500 A,the forging time is 0.2 seconds,and the weld position is air-cooled or slowly cooled,greatly improving the welding quality of wheel steel products and reducing the probability of welding cracks.