The mechanical properties of austempered 1.75Ni-1.5Cu-0.5Mo alloyed PM steels


GÜRAL A., Altuntaş O., Sarıçiçek N.

Canadian Metallurgical Quarterly, 2023 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Publication Date: 2023
  • Doi Number: 10.1080/00084433.2023.2245203
  • Journal Name: Canadian Metallurgical Quarterly
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Aerospace Database, Chemical Abstracts Core, Communication Abstracts, Compendex, INSPEC, Metadex, Civil Engineering Abstracts
  • Keywords: austempering, isothermal annealing, microstructure, PM steels, tensile properties, toughness
  • Gazi University Affiliated: Yes

Abstract

The effects of isothermal annealing on the microstructure and mechanical properties of ferrous based Ni-Cu-Mo-C diffusion alloy powder metallurgy (PM) components were investigated. For this purpose, the powder mixtures were pressed and sintered at 1150 °C. After full austenitisation at 825°C, they were kept isothermally in a neutral salt bath at 450°C for 15–120 min. Microhardness (HV 0.01), tensile and impact toughness tests of the samples were carried out at room temperature. The hardness value decreased with increasing austempering time. As a result of the austempering of 120 min, the tensile strength increased by 12.2% and became 460 MPa compared to the heat treatment period of 15 min, and the impact toughness was determined to be 14.3 j.cm−2 with an increase of 21%. Under the conditions in this experimental study, optimum strength and ductility values were obtained with austempering time applied in the range of 90–120 min.