EFFECT OF DEEP CRYOGENIC TREATMENT ON SURFACE INTEGRITY AND DIMENSIONAL STABILITY OF D2 TOOL STEEL

Tushar M. Sonar, Sachin V. Lomte

Abstract: Deep cryogenic treatment is an add-on process to conventional heat treatment in which material is treated at cryogenic temperature. The mechanical properties of the tool steel are significantly improved by Deep Cryogenic treatment. Surface integrity and dimensional stability is having greater impact on the functional performance of the tool during service conditions. The objective of this work is to investigate the effect of deep cryogenic treatment on the surface integrity and dimensional stability of the D2 tool steel. The metallographic samples and Navy C Rings of D2 Tool steel were treated at cryogenic temperature of - 1930C after hardening and tempering. Results have shown improvement in surface roughness. The improved surface roughness is attributed to the release of tensile residual stresses and more precipitation and uniform distribution of fine secondary carbides. DCT have higher shape distortion than CHT. The distortions in DCT can be attributed to the section sensitivity of D2 Tool steel.

Keywords: Surface integrity, distortion, precipitation of secondary carbides, section sensitivity

DOI: https://doi.org/10.15623/ijret.2015.0408013