Development of an Armor Steel for Ballistic Protection

Abstract In this study, a newly developed Boron alloyed armor steel is presented and its mechanical properties as well as its ballistic applications are given. Further, a description of ballistic terms is included to understand the development of armor steel for the use in civil and defence applications. The main subject of the study is the microstructural design of these steels. For this purpose a Boron alloyed experimental steel has been produced by quenching and tempering. The microstructures obtained after such heat treatments have been examined by light microscopy (LM) and scanning electron micoscopy (SEM). The application of precipitation hardening is highlighted by the effect of alloying elements and the resulting matrix hardening potential. As a result, a suggestion is given for the alloy design of the new armor steel with Boron additions. The effect of microstructure and mechanical properties (strength, hardness, toughness, etc.) of this experimental armor steel have been evaluated by methods similar to homogeneous rolled armor steels (MIL-A-12560) targeted at a good ballistic performance. Also the effect of heat treatment on the mechanical properties of armor steel is shown. The impact toughness values at different test temperatures are comparatively given in addition to the relationship between ballistic performance and hardness for armor steels. Attempts have been undertaken to explain the cause of deformation and failure occurred in the steel plates due to projectile penetration with light and scanning electron microscopical studies.