Deep Cryogenic Treatment Improves Wear Resistance of En 31 Steel

Abstract

Cryogenic treatment is an inexpensive supplementary process to conventional heat treatment, which improves the tribological properties of steels. A study has been made on the effect of cryogenic treatment on En 31 steels done at different stages of heat treatment. It is observed that through cryogenic treatment the wear can be decreased by a maximum of 75% depending on the service conditions. Scanning electron microscopy (SEM) study was also conducted to identify the possible mechanism which augments the improvement in wear resistance (WR) in cryogenically treated En 31 steels. Based on the study it is also confirmed that the cryogenic treatment should be done before tempering immediately after quench hardening to obtain maximum benefits.

Keywords:

• Austenite to martensite transformation
• Bearing steel
• Carbide precipitation
• Cold treatment
• Deep cryogenic treatment
• En 31 steel
• Hardness
• Heat treatment
• Liquid nitrogen
• Material processing
• Mechanical properties
• Microstructural studies
• Subzero treatment
• Tribology
• Wear resistance

ACKNOWLEDGMENT

The authors acknowledge the financial support from the All India Council for Technical Education (AICTE), New Delhi for conducting this research work. The authors also gratefully acknowledge M/s.Chennai Metco Private Limited for extending their metallurgical facilities for the successful completion of the work.