摘要：Armour steel is a high strength and hardness steel used to protect damage by an object, individual or vehicle from the direct pressure of projectile. This steel used for military and commercials equipment in Indonesia and produced out of hot rolled plate steel made by PT. Krakatau Steel (Persero) Cilegon, Banten, Indonesia. By using quench (with water sprayed) and temper heat treatment produced Quenched & Tempered Steels. The aim of the study to obtain optimum quenching and tempering parameter in hardness and impact energy of HRP Steel. Method of this study by optimizing austenite temperature; austenite holding time; temper temperatures; hardness and impact energy. The result of this study is austenite temperatures 900°C (held 45 minutes) and temper temperatures 125°C (held 45 minutes). Prediction of both hardness and impact energy is 569.96 HVN (536.00 BHN) and 30.50 J respectively.
