Effect of Sulfur Contents on Properties and Inclusions in High Speed Wheel Steels

Effect of different contents of sulfur on the properties and inclusions in the high speed wheel steels was investigated. Inclusions (MnS, Al2O3) in the high speed wheel steels were observed by scanning electron microscopy (SEM) and statistically analyzed. The results show that, the impact toughness of the wheel steels increases with the ascending of sulfurs (0.002%-0.014%) at the beginning and gets the maximum at 0.011% then descends, while the strength remain almost the same level. The reason is that the increasing of the sulfur contents can effectively promote the covering ablity of MnS to Al2O3, which is good to the toughness of steels. However, too large content of sulfur is harm to the toughness of the wheel steels, for the excessive amount of MnS is got in this case.