Effect of austenitizing temperatures on the microstructure and mechanical properties of AISI 9254 steel

Murathan Ö. F., Davut K., KILIÇLI V.

MATERIALS TESTING, vol.63, no.1, pp.48-54, 2021 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 63 Issue: 1
  • Publication Date: 2021
  • Doi Number: 10.1515/mt-2020-0007
  • Journal Name: MATERIALS TESTING
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.48-54
  • Keywords: High silicon steel, austenitizing temperatures, carbide-free bainite, bainite, martensite
  • Ankara University Affiliated: No

Abstract

In this study, the effect of austenitizing temperatures and low-temperature isothermal heat treatment (below martensite start temperature) on the microstructure and mechanical properties of AISI 9254 high silicon spring steel has been investigated. Experimental studies show that ultra-fine carbide-free bainite, tempered martensite and carbon enriched retained austenite could be observed in isothermally heat-treated samples where the as-received sample consisted of fine pearlite. A high tensile strength of similar to 2060 MPa, a total elongation of similar to 8 %, and absorbed energy of 105 J were achieved in a commercial high-Si steel by austempering below the Ms temperature. A good combination of strength and ductility has been obtained in prolonged austempering below the martensite start temperature (225 degrees C) from an austenitizing temperature of 870 degrees C.