Comparision of Direct Quenching and Reheat Quenching Process on Microstructure and Mechanical Properties of a High Strength Steel

Abstract

The effects of direct quenching and tempering (DQ-T) process and conventional reheat quenching and tempering (RQ-T) processes on the microstructure and mechanical properties of a high strength low alloy steel were investigated. In the as-quenched DQ steel, prior austenite grains are elongated parallel to the rolling direction, whereas the as-quenched RQ steel mainly consists of equiaxed grains; The DQ process was found to enhance the hardenability of steel effectively. The tensile strength and yield strength of DQ specimen, were higher than that of RQ specimen. In contrast, low temperature toughness of DQ-T specimen was generally inferior to that of RQ-T specimen.

Temperature-dependent properties of high-strength steel for evaluating the fire resistance of structures

“…It has been shown that quenching process can effectively improve the strength of the steel (Hui et al, 2002). The hardness and strength gradually increase with the increases of quenching temperature, but when the quenching temperature exceeds 1000°C, the changes in hardness and strength are not significant (Duan et al, 2012). The mechanical properties of steel after fire exposure are closely influenced by the microstructure of the material (Azhari et al, 2017; Azhari et al, 2018).…”