Acceleration of spheroidisation in a medium carbon steel processed by equal channel angular pressing

Abstract

A medium carbon alloy steel was processed using equal channel angular pressing (ECAP) with a view to accelerating the softening process during subsequent annealing. The steel was pressed at 600◦C for up to four passes. The original well-aligned lamellar cementite became bent and discontinuous with increasing number of passes. Complete spheroidisation was achieved after annealing at 720◦C for only 30 minutes, resulting in the same hardness as that obtained after 72 hours without ECAP. This can potentially lead to significant cost reduction and environmental benefit for the industry.