Thermal-fatigue of Roller Surfacing Metal

By means of self-designed test method, thermal-fatigue resistance and influence factor for surfacing metal of three self-produced flux-cored wires and one solid wire for roller hardfacing were studied deeply. The mechanisms of thermal-fatigue crack initiation and extension were investigated. The results show that the thermal-fatigue crack initiation and extension were related to cycle stress and high-temperature oxidation. The more oxidation resistance, the more crack initiation resisting. Besides, thermal-fatigue resistance were effected by microstructure and inclusion in surfacing wetal. The homogeneous microstructure is advantageous to increase thermal-fatigue resistance, but inclusions facilitate the initiation, extension and branch of crack.