Investigation of Microstructure and Mechanical Properties of Heat Treatment, Carbon Ratio and Alloying Elements in AISI 1008, 1040 and 4140 Steels

Most of the metal materials used in the industry are made of steel. Among the main reasons for the common use of steel materials are abundance, economical shaping and a wide range of mechanical properties. The basic alloy element of the steels is carbon (C) and shows different properties depending on its composition. In addition, alloying elements significantly affect a number of mechanical properties such as tensile strength, yield strength, impact strength, ductility and machinability by making a difference in the microstructure of the steel. In this study, the effect of carbon ratio between AISI 1008 and 1040 steel and some alloying elements between AISI 1040 and 4140 steels were investigated experimentally. During the analysis process, three different types of steel; specimens were prepared without any heat treatment of the stock steels for tensile testing, microhardness test and microstructural imaging of the light metal microscope. Samples were also prepared in order to see the effect of heat treatment in the tensile test. Load-controlled tensile test, microVickers hardness test and microstructure imaging were performed for the prepared samples. As a result; both the carbon ratio and the effect of the alloying elements increase the yield and tensile strength, and the % elongation and % section shrinkage values decrease. Carbon ratio is more effective in tensile strength and % shrinkage, while alloying elements are more effective in yield strength and % elongation