Enhancement of the mechanical properties of EN52CrMoV4 spring steel by deep cryogenic treatmentVerbesserung der mechanischen Eigenschaften von EN52CrMoV4 Federstahl durch Tieftemperaturbehandlung


ÖZDEN R. C., Anik M.

MATERIALWISSENSCHAFT UND WERKSTOFFTECHNIK, vol.51, no.4, pp.422-431, 2020 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 51 Issue: 4
  • Publication Date: 2020
  • Doi Number: 10.1002/mawe.201900122
  • Journal Name: MATERIALWISSENSCHAFT UND WERKSTOFFTECHNIK
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aerospace Database, Applied Science & Technology Source, Communication Abstracts, Compendex, INSPEC, Metadex, Civil Engineering Abstracts
  • Page Numbers: pp.422-431
  • Keywords: Spring steel, cryogenic treatment, residual stress, microstructure, mechanical properties, BEHAVIOR, MICROSTRUCTURE, AUSTENITE, STRENGTH, REFINEMENT
  • Eskisehir Osmangazi University Affiliated: Yes

Abstract

The effect of the deep cryogenic treatment on the micro-structure and mechanical properties (tensile strength, toughness, residual stress and fatigue strength) of the medium carbon spring steel, which is subjected to different heat treatment steps, is investigated. Deep cryogenic treatment causes spring steel to keep compressive residual stress more efficiently due to an increase in the density of the crystalline defects, retardation in the stress relief after the phase transformations and nano-cluster carbide formations. If deep cryogenic treatment is applied before the tempering then the homogeneously distributed fine carbides form after the tempering and the grains remain relatively fine. The microstructure with homogeneously distributed fine carbides and fine grains cause spring steels to have simultaneously enhanced tensile strength, ductility and fatigue strength. If deep cryogenic treatment is applied after the conventional heat treatment (quenching+tempering), however, the coarse carbides form in the micro-structure and the improvement in the mechanical properties of the spring steel is limited.