Investigation of microstructures and properties of 440c martensitic stainless steel

Salleh S.H., and Omar M.Z., and Syarif J., and Ghazali, M.J., and Abdullah S., and Sajuri Z., (2009) Investigation of microstructures and properties of 440c martensitic stainless steel. International Journal of Mechanical and Materials Engineering, 4 (2). pp. 123-126. ISSN 1823-0334

Affiliations

Universiti Kebangsaan Malaysia, Faculty of Engineering and Built Environment, Dept. of Mechanical and Materials Engineering
Universiti Kebangsaan Malaysia, Faculty of Engineering and Built Environment, Dept. of Mechanical and Materials Engineering
Universiti Kebangsaan Malaysia, Faculty of Engineering and Built Environment, Dept. of Mechanical and Materials Engineering
Universiti Kebangsaan Malaysia, Faculty of Engineering and Built Environment, Dept. of Mechanical and Materials Engineering
Universiti Kebangsaan Malaysia, Faculty of Engineering and Built Environment, Dept. of Mechanical and Materials Engineering
Universiti Kebangsaan Malaysia, Faculty of Engineering and Built Environment, Dept. of Mechanical and Materials Engineering

Abstract

440C steel is a high-carbon martensitic stainless steel with excellent mechanical properties. This paper describes the effect of heat treatments on microstructures and mechanical properties of 440C steel. Solution treatment was carried out at 1150oC and 60 minutes holding, followed by tempering process at 660oC with various holding time. In the as-quenched sample, SEM and EDX revealed existence of M7C3 carbides within the martensitic structures. While after tempering, M23C6 carbides were identified along with M7C3 carbides. Hardness tests found out that tempering at 30 minutes resulted in maximum hardness value of 49HRC. However, the hardness of the as-quenched sample was 43HRC. Tensile tests at this tempering time showed YS of 368MPa and UTS of 1044MPa. As comparison, the as-quenched sample showed YS of 124MPa and UTS of 517MPa. It is believed that secondary hardening phenomenon occurred while tempering and influenced the value of hardness and tensile strength of the 440C steel.

Item Type:

Journal

Keywords:

Tempering, Microstructures, Hardness, Secondary hardening.

Subjects:

T Technology, Engineering

ID Code:

10285