마모된 철도차량 차륜의 육성용접 및 용접부 특성평가

초록

When a railway vehicle rolls in a straight line, the wheel-rail rolling contact mostly occurs on the wheel tread and railhead top surface. On a curved line, sliding contact also occurs between the wheel flange and railhead side, which wears and thins the wheel flange down. The wheel flange supports the lateral force transmitted by the centrifugal force of the vehicle. So a certain thickness is necessary for structural safety. When the flange thickness becomes thinner than the specified value, the wheel profile is restored by machining, which shaves off much of the wheel rim, so the wheel reaches the end of its life after several times of reprofiling. It is inferred that more than a million railway wheels are discarded globally every year due to flange wear. In this study, the main focus is on developing an overlay welding process using submerged arc welding. Mechanical property characterization, microstructural examination, residual stress measurement, rolling contact wear tests were carried out.