A Characteristics of Heat Affected Zones of the Damaged Rod Type Cast Steel Coupler According to Repair Weldment Conditions

손상된 Rod Type Coupler 주강재의 보수용접에 따른 열영향부특성

Cast steels have been mainly in rod type couplers which connect railway vehicles. These components, as important members, are exposed to repeat to repeated stresses and impact loading during stop and departure service for a long tie. The coupler suffers fatigue crack initiations and demage that cause need to repair weldment due to these loading conditions. Therefore, the heat affected zone of cast steel couple in rod type were evaluated in view of metallurgical weld characteristics after repair welding at laboratory. The specimens with two different welding techniques were evaluated after several welding conditions and post-heat treatments. Micro-vickers hardness and tensile tests and microstructural observations were conducted on heat affected zone of the weldment according to repair weld and post-heat treatment.