MICROSTRUCTURAL CHARACTERIZATON AND EFFECTS ON MECHANICAL PROPERTIES OF BORON ADDED ARMOR STEELS

Abstract

The performance of steels depends on the properties associated with their microstructures, that is type, volume fraction, form factor, size and the area distribution of the various phases involved. Because all the phases in steels are crystalline, steel microstructures are made up of various crystals, sometimes as many as three or four different types which are physically blended by solidification, solid-state phase changes, hot deformation, cold deformation and heat treatment. Each type of microstructure is developed to characteristic property ranges by specific processing routes that control the microstruc tural changes. Thus processing technologies are used to tailor the final microstructure. In this study boron added armor steel has been rolled to form sheet product. Austenitization treatment, rapidly quenching and then tempering at various temperatures and times have been performed on the materials respectively. After all of these operations, the phases of the alloy system formed during equilibrium state have been examined and also their amounts are calculated with Thermocalc. Microstructures formed after different heat treatments have been examined by optical microscopy. The effect of formed microstructures on mechanical properties are comparatively given by strength, toughness and elongation values.