Effect of Pearlite Banding and Weld Texture on Wheel Rim Failure in Resistance Upset Butt Welding

Weld thermal cycle during resistance upset butt welding (UBW) of high-strength low alloyed steel (HSLA) leads to the phase transformation of the region with pearlite banding to martensite due to its very high carbon equivalent compared to that of the parent material. Cracking of the weld was observed at the bond line and not at the CGHAZ and FGHAZ. The presence of detrimental Goss (110) [001], rotated Goss (110) 1 1 ¯ 0 and rotated cube (001) 1 1 ¯ 0 , (001) 11 ¯ 0 textures at the bond line enabled easy propagation of micro-cracks that were generated at the bond line during the flaring stage of wheel rim manufacturing. The cooling rate at the run-out table and the hot rolled coil coiling temperature were optimized to eliminate the pearlite banding, leading to a sound weld with better formability.