The Effect of Si Content on Microstructures and Mechanical Properties of Normalized Pressure Vessel Steel A517 Grade Q

Abstract

This research aims to investigate the effect Si on microstructures and mechanical properties of normalized pressure vessel steel A517 Grade Q. The Si contents were varied from 0.5, 0.9, 1.2, and 1.6. The normalizing process was carried out at 920 °C in 10 minutes. The microstructures were characterized by optical light microscope and Scanning Electron Microscope (SEM), and The mechanical tests were conducted by hardness, tensile, wear, and impact testing machine. The microstructures and mechanical properties were investigated. The results of the microstructures test show that the phases of the material are bainite and ferrite. The increase of Si content will refine and distribute the bainite phase in the ferrite matrix. The mechanical tests show that the Si content will affect the mechanical properties such as hardness, tensile strength, ductility, wear resistance, and toughness. The Increase of Si content from 0.5 up to 1.2 will increase the hardness, tensile strength, and wear resistance, and will decrease the elongation and toughness of the normalized pressure vessel steel A517 grade Q. The mechanical properties seem constant from 1.2 up to 1.6 of Si.