The precipitation behavior of second phase in high titanium microalloyed steels and its effect on microstructure and properties of steel

Abstract

The thermodynamic precipitation behavior of the second-phase particles in Nb-containing high titanium microalloyed steel has been studied by calculation in this article. It is revealed that FCC_A1#2 is isomorphic with FCC_A1#3 and the contents of Ti and Nb elements are much higher than that of FCC_A1#3. The influence of different quenching temperatures on microstructure and mechanical properties of steel was also studied. The results indicate that the quenching temperature should be controlled below 1,100°C and the soaking time should not exceed 60 min to avoid abnormal grain growth. The thermodynamic calculation and experimental results have certain theoretical guiding significance for the practical industrial application of high titanium–niobium steel.

Keywords

• precipitation behavior
• microalloyed steels
• impact toughness