Effects of V addition on improvement of heat shock resistance and wear resistance of Ni–Cr–Mo cast steel brake disc

It is important to improve the heat shock resistance and wear resistance of discs for railway cars for long-term and safe use. We have studied the effects of additional elements on the heat shock resistance of Ni–Cr–Mo steel used for the production of brake discs. In this paper, the effects of V addition on Ni–Cr–Mo steel are discussed. It was clarified that the hardness near the friction surface is as high as that of high hardenability steel, and the heat shock resistance is improved by the addition of 0.1% V. It was also determined that V addition prompted a transformation to lower bainite, which has high toughness and hardness.