Cause Analysis and Prevention of Brittle Fracture of SWRH82B Wire Rod in Use

Using stereo light microscope, metallographic microscope, chemical composition analysis, scanning electron microscope, electron spectrum and microhardness, three typical brittle fractures of SWRH82B wire rod during use were analyzed, including cup cone fracture, head and tail brittle fracture on pay-off bobbin and oblique stubble fracture. The results show that the main reason for the cup-cone fracture is serious positive segregation of the composition in the center of the wire rod and improper cooling control, which causes the core to form a network of cementite. Brittle fracture and oblique stubble fracture are all caused by the formation of hard and brittle deformed martensite on the surface due to violent collisions, scratches and other external effects. Specific process improvement measures were proposed for three typical fractures, which can effectively reduce the probability of the above-mentioned brittle fracture of SWRH82B wire rod.