加热温度和Nb对弹簧钢60Si2CrVAT完全脱碳层深度和形貌的影响

Effects of heating temperature and niobium microalloying on complete decarburized depth and microstructure of spring steel 60Si2CrVAT

通过箱式电阻炉等温加热实验,研究了加热温度和0.037%Nb微合金对弹簧钢60Si2CrVAT表面完全脱碳层深度和形貌的影响。实验结果表明：加热时间为90min时,弹簧钢60Si2CrVAT完全脱碳层形成温度为725~925℃,完全脱碳层中铁素体为粗大的柱状晶,并且存在一个完全脱碳敏感的温度区间800~875℃,850℃时完全脱碳层深度达到最大。添加0.037%Nb并没有对弹簧钢60Si2CrVAT完全脱碳层深度有明显影响,但是显著影响了完全脱碳层形貌。

Effects of heating temperature and 0. 37% Nb microalloying on complete decarburized depth and microstructure of spring steel60Si2CrVAT was investigated by isothermal heating experiments in a box-type resistance furnace. The results show that complete decarburization occurs between 675 ℃ and 875 ℃ when the holding time is 90 min. Decarburization sensitivity is high in 800-875 ℃,and the maximum depth is found at 850 ℃. The ferrite grains in the complete decarburized layer are thick columniform. After the addition of 0. 037Nb% niobium,no obvious effect on complete decarburized depth is found,but the significant effect on microstructure of the complete decarburized layer is observed.