The effects of heat treatment on the mechanical properties of 450 HB wear resistant steel

The effects of heat treatment on the mechanical properties of 450 HB wear resistant steel produced by Usiminas steelworks in the form of heavy plates were investigated. The results showed that when tempering temperature is lower than 200°C, there are no significant changes in hardness, tensile properties and absorbed energy in Charpy V-notch test. With further increase in temperature up to 400°C, hardness, tensile strength, total elongation and impact toughness exhibited a slight downward trend. For heating carried out from 400°C to 600°C, a very significant drop in hardness and tensile strength and an increase in total elongation and absorbed energy values were observed. The abrasive wear resistance, evaluated by dry-sand rubber wheel test, increased with the heating up to 500°C. With the additional rise in temperature to 600°C, the abrasive wear resistance decreased, reaching a similar level to the reference state (steel in as-delivered condition).