Mechanical properties and microstructures of steel panels for laminated composites in armoured vehicles

Abstract

This paper present the study about the mechanical properties of two high strength low alloy steels for replacing the current rolled homogeneous armour (RHA) for ballistic application. High strength low alloy steel has been widely adapted as a ballistic plate in light armoured vehicle. However, the current used RHA plate is very heavy thus restricted the manoeuvrability of the armoured vehicle. The aim of this study is to find materials suitable to be used for production of composite protection panel which is lighter yet has similar mechanical properties to RHA. The tensile strength and hardness of AISI 4340 and AR500 steels were evaluated and compared to that of RHA and the results were analysed based on its chemical compositions and microstructural observation. Values of these properties are primarily reflected by its microstructures and chemical compositions. Therefore, microscopic observation of microstructural arrangement and phases are essential in understanding the hardness and stress-strain behaviour of these metals. Results indicate similar tensile properties were observed in RHA and AR500 but different properties obtained for AISI 4340. Tensile strength of RHA and AR500 were 1750 MPa and 1740 MPa respectively followed by AISI 4340 at 1020 MPa. AISI 4340 steel exhibited the highest elongation at 20.6% compared to RHA and AR500 at 13.3 and 12.5%, respectively. Higher degree of carbon content in fine martensitic structure of RHA and AR500 led to high hardness. Imperfections in RHA and AR500 were also removed by hot rolling process as indicated by white banding that cause higher in tensile strength. Retained austenite and coarse microstructure of AISI 4340 steel contributed to higher ductility compared to AR500 and RHA. Therefore the tensile properties of RHA and AR500 were found similar due to its microstructure behaviour. This similarity allows AR500 to be utilised as alternatives to RHA in armour plate application.

Dry sliding wear behaviour of ultrasonically-processed AA6061/SiCp nanocomposites

“…The properties of the MMC depends on the type of matrix material, type of reinforcement, reinforcement particle size and fabrication process [1][2][3]. The micron size reinforced metal matrix composites can achieve good strength; however, the ductility of the material reduces.…”

Investigation of micro-structure and mechanical properties of three steel alloys

“…This paper investigated the microstructural behaviour and mechanical properties of three high strength low alloy sheets of steel used for armoured vehicle and found that the tensile strength of RHA had the highest value compared to other two AR500 and AISI 4340 sheets of steel [38]. The toughness of steel material depends on its chemical composition and microstructure [39]. The investigation of microstructure and mechanical properties of stainless steels having 0.004 wt %C to 0.034 wt %C was conducted and the martensitic texture was found to be influenced by carbon content [40].…”

Material and technological investigation of machined surfaces of the OCHN3MFA steel

“…The achieved results of the research published in the authors' articles [1][2][3] as well as the knowledge obtained from industrial practice show the need to evaluate the surface conditions of these parts as the result of a particular technological process depending on specific operating conditions of the surface in operation. It is precisely this view of surface assessment that is often referred to as surface integrity.…”