The Effect of Austenization Temperature in Surface Hardening Process on Steel Plate as Ballistic Plate

Abstract

Ballistic resistant plate is a plate that is able to withstand the rate of projectiles. Ballistic resistant plates or armor plates are applied to military vehicles. It requires a combination of hardness, strength and toughness. Surface hardening with heat treatment is carried out to obtain ballistic resistant properties. The article is aimed at increasing the hardness of one of the surface in commercial medium carbon steel. The variation of austenization is done at the temperatures of 700, 800 and 900 °C with induction heating and holding time for 3 seconds. The quenching media used 15 litters of oil. Several tests are conducted: The results of surface hardening are observed in microstructure, distribution of hardness is tested by micro vickers, tensile testing and impact testing. Tensile testing in accordance with ASTM E8 standards and impact testing with E 23 standards. The transformation of ferrite and perlite to marten site is obtained on the surface of the plate in the temperature of 900 °C. At that temperature, hardness increases on the surface and tenacity can be maintained. In addition, the value of hardness, tensile strength and impact energy were significantly increased. Impact energy as a material requirement for ballistic resistance had been achieved, but hardness and tensile strength still need to be increased.