Determining Thermal Parameter Windows of 40Cr10Si2Mo Steel from an Enhanced Processing Map

Abstract

The properties of a hot-deformed component can be enhanced by planning its forming process within the desired thermal processing-parameter windows associated with dynamic recrystallization (DRX). In order to determine the windows of 40Cr10Si2Mo steel, hot compression tests were employed within the deformation conditions of 1173-1398 K and 0.01-10 s-1. Following this, the hot processing maps, which distinguished the parameter domains with stable plastic deformation, were established according to the stress-strain data. The DRX domains were further identified within the stable deformation domains and represented as a map illustrating the deformation mechanisms of this steel. The deformation activation energy, which describes the forming difficulty degree of material, was calculated, and its evolution map with parameters was constructed. The deformed microstructures were characterized utilizing a scanning electron microscope (SEM) to verify the deformation mechanism map. An enhanced processing map which superimposed the activation energy map over the deformation mechanism map, was developed. The resulting map facilitated the determination of optimal windows that ensure DRX mechanism and lower activation energy. The optimal windows for 40Cr10Si2Mo steel were finally obtained as: 1322-1398 K & 0.016-0.35 s-1 and 1344-1380 K & 0.035-0.126 s-1.

Keywords

• 40Cr10Si2Mo steel
• dynamic recrystallization
• deformation activation energy
• processing map