The Effect of the Sintering Temperature and Addition of Niobium and Vanadium on the Microstructure and Mechanical Properties of Microalloyed PM Steels

Abstract

In this work, the effect of the sintering temperature on the microstructure and mechanical properties of Nb-V added powder metallurgy (PM) steels was investigated. The microstructure and mechanical properties of the Nb-V added PM microalloyed steel were examined by optical microscopy, scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), optical emission spectrometer (OES), tensile and hardness tests. Results indicated that the optimal sintering temperature was 1350 °C and the addition of 0.1%, 0.15% or 0.2% of Nb-V increases the yield strength (YS), ultimate tensile strength (UTS) and hardness of the PM sintered steels. 0.2 wt % Nb-V added PM steel showed the highest values in yield strength (YS), ultimate tensile strength (UTS) and the highest hardness. Elongation also tends to improve with adding Nb-V content. In addition, Nb-V limited grain growth during austenitization.

Keywords

• powder metallurgy
• Nb-V microalloyed steels
• microstructure
• mechanical properties
• tensile test
• hardness