Weld Cracking Analysis of 380CL Steel Rim Welded by Flash Butt Welding

The weld cracking reason of 380CL steel rim welded by flash butt welding was analyzed by using optical microscope, scanning electron microscope and so on. The results show that the weld cracking of the rim was brittle cracking. The coarse widmansttten structure, which was produced due to the abnormal growth of grains in weld seam and the rapid cooling rate after welding, was the main reason for the cracking failure. By optimizing the flash butt welding process, shortening high-temperature residence time in the weld center to effectively control the weld austenite grain size and ensuring a good strength and toughness property of the weld would prevent the weld cracking.