Microstructure, residual stress, and mechanical property evolution of a spray-formed vanadium-modified high-speed steel processed by post-heat treatment

Abstract

A vanadium-modified high-speed steel (HSS) manufactured by spray forming (SF) process was subjected to different heat treatment processes and the resultant microstructural evolution and mechanical properties were investigated. In-situ high-temperature Vickers indentation associated with high-temperature tensile tests were utilized to evaluate the changes in hardness and residual stress with temperature for samples processed by annealing. Moreover, the effect of quenching temperature on hardness, bending strength and impact toughness was investigated. The secondary carbide precipitation behavior and its strengthening mechanisms were discussed in combination with transmission electron microscopy (TEM) characterization. A possible mechanism was proposed to elucidate the evolution of carbide precipitation behavior during different heat treatment processes. We envision the results gained from the present study would provide useful guidance for understanding the evolution of microstructure and mechanical properties of spray-formed HSSs processed by different heat treatment conditions and optimizing the alloy design and post–thermal mechanical processing of HSS.

Keywords

• High-speed steel
• Heat treatment
• Microstructure
• Mechanical properties
• Secondary carbide