Hardness and impact energy absorbed produced by Q&T steel and DQ&T teel

Abstract

Abstract Hot rolled plate steel is heat treatable steel made in Indonesia for commercially developed to Quenched and Tempered Steel. This steels made by PT. Krakatau Steel (Persero) Cilegon, Banten, Indonesia. The aim of this study to improve the hardness and energy impact through heat treatment of double quench + temper. The method used is heating up to 900°C (maintained for 30 minutes and cooled by water) for fives specimen hot rolled plate steel and produce the quenched 900 steel (Q900 Steel). Four Q900 steel specimens were heated at 750°C, 800°C, 850°C, and 900°C (maintained for 30 minutes) each. Then five specimens (include Q900 Steel) are tempered at 150°C (maintained for 30 minutes) and produced Q900 & T Steel, Q900+750 & T Steel, Q900+800 & T Steel, Q900+850 & T Steel, Q900+900 & T Steel. Results of the study were changes in microstructure, hardness and impact energy. Hardness and impact energy absorbed of Q900+750&T Steel higher than Q900 &T Steel.