Development of Cast Steel Brake Disc with Heat Shock Resistance

摘要

Recently, the maximum running speed of railway cars and braking load continues to increase leading to the need to improve the heat shock resistance of railway cars discs. In this study, the heat shock resistance of two materials with different hardenability was compared in the braking tests. In discs with good hardenabilty, hardness near the friction surface was increased and many cracks were observed. The white layer was clarified to be martensite. On the other hand, in discs with poor hardenabilty, hardness hardly changed and the heat shock resistance was good. The white layer was clarified to be tempered martensite.