Investigation of the Effects of Static Deformation Aging Treatment on the Tensile Strength of a Plain Carbon Powder Metal Steel

Abstract

In this study, the effect of annealing temperatures on the deformation aging of 0.4% C steels produced by Powder Metallurgy (PM) method was investigated. For this purpose, 0.4% by weight natural graphite powder and 0.3% by weight zinc stearate are added to pure iron powder. Micro tensile test samples were produced by shaping the obtained powder mixtures at room temperature and at a pressure of 700 MPa in a single-axis mold. Then it was left to sintering for 30 minutes under an atmosphere of pure argon gas at 1180 ºC. 4% pre-deformation was applied to the medium carbon powder metal steels produced after sintering. Then, aging treatment of 30 minutes was carried out at 200, 300 and 400ºC temperatures, respectively. After aging deformation, powder metal steels; microstructure, hardness, broken surface and tensile properties were investigated. As a result of static deformation, the highest yield strength and hardness value were seen in the samples where static deformation aging at 200 ºC was applied.

Keywords

• deformation aging
• powder metallurgy steel
• fracture surface