EXPERIMENTAL STUDY ON DEFORMATION AND DENSIFICATION PROPERTIES OF SINTERED ATOMET 4601+TIC ALLOY STEELS UNDER COLD UPSETTING

Abstract

The present investigation is focussed on to develop and study the densification and deformation of cold forged prealloyed ATOMET 4601 and admixed with 2% TiC high strength alloy steels. Elemental TiC powder was homogeneously mixed with ATOMET prealloyed powder through Powder Metallurgy (P/M) route. The physical properties of P/M alloy steel powders were measured as per the ASTM Standards. The cylindrical sintered preforms of size Ø25x12 mm were used for the present work. In order to study the plastic deformation and densification characteristics of the alloy steels preforms, the specimens were subjected to cold upset with an incremental load. The axial load was increased upto the appearance of fine cracks on the lateral surface of the deformed alloy steel preforms. Physical measurements have been taken on deformed and undeformed specimens to calculate stress and strain values. The density of specimens was evaluated by the Archimedes’ principle for the as sintered and the specimen after each deformation. The influencing parameters such as true axial stress, true height strain, true lateral strain, density and hardness were correlated each other for the deformation and densification studies of the alloy steels. Microstructures of alloy steels taken by optical microscope were also corroborated with deformation properties. It is found from the plots that addition of TiC to prealloyed powder deteriorates the plastic deformation and densification properties of ATOMET 4601 alloy steel. The titanium carbides embedded between the ferrite gains drastically affect the plastic flow of TiC added alloy steel.