Simplification of heat treatment process in a tool steel by aluminium addition

Abstract

A novel concept for simplification of heat treatment process in a tool steel by the addition of aluminium has been proposed in this research. The addition of 1.08 wt-% aluminium leads to an approximately fully pearlitic state, of which the cementite lamellae are largely spheroidised. Excessive addition of 1.58 wt-% aluminium would result in the formation of a large amount of δ-ferrite. These results are mainly attributed to the synthetic effect of aluminium on the driving force of pearlite transformation and the inter-spacing distance between the proeutectoid carbides. The mechanical properties’ analyses show that aluminium has promising potential to substantially simplify the processing method for developing a relative low-cost mould steel without the concomitant mechanical properties’ reductions.

Keywords:

• Steel
• Phase transformation
• Pearlite
• Microstructure control
• Mechanical properties
• Aluminium

Acknowledgements

The authors wish to acknowledge the financial support of the Science and Technology Development Project of Jilin Province (Grant No. 20130301006GX and No. 20140204042GX).