ISSN (Print): 2328-3491, ISSN (Online): 2328-3580, ISSN (CD-ROM): 2328-3629 American International Journal of Research in Science, Technology, Engineering & Mathematics AIJRSTEM 14-793; © 2014, AIJRSTEM All Rights Reserved Page 195 AIJRSTEM is a refereed, indexed, peer-reviewed, multidisciplinary and open access journal published by International Association of Scientific Innovation and Research (IASIR), USA (An Association Unifying the Sciences, Engineering, and Applied Research) Available online at http://www.iasir.net Effect of Various Heat Treatment Process on Tensile Strength and Elongation of Stainless Steel Amit Kumar Tanwer Department of Mechanical Engineering, Roorkee Institute of Technology, Roorkee, Roorkee-247667, Uttrakhand, INDIA. I. Introduction Heat treatment is a combination of timed heating and cooling applied to a particular metal or alloy in the solid state in such ways as to produce desired mechanical properties (ultimate tensile strength and percentage elongation). Annealing, normalizing and Quenching are the most important heat treatments often used to modify the mechanical properties of engineering materials particularly steels. Annealing is the type of heat treatment most frequently applied in order to soften iron or steel materials and refines its grains due to ferrite-pearlite microstructure; it is used where elongations and appreciable level of tensile strength are required in engineering materials [3]. In normalizing, the material is heated to the austenitic temperature range and this is followed by air cooling. This treatment is usually carried out to obtain a mainly pearlite matrix, which results into strength and hardness higher than in as received condition. It is also used to remove undesirable free carbide present in the as-received sample [1]. Steels are normally hardened and tempered to improve their mechanical properties, particularly their strength and wear resistance. In quenching, the steel or its alloy is heated to a temperature high enough to promote the formation of austenite, held at that temperature until the desired amount of carbon has been dissolved and then quench in oil or water at a suitable rate. Also, in the harden condition, the steel should have 100% martensite to attain maximum yield strength, but it is very brittle too and thus, as quenched steels are used for very few engineering applications. By tempering, the properties of quenched steel could be modified to decrease hardness and increase ductility and impact strength gradually. The resulting microstructures are bainite or carbide precipitate in a matrix of ferrite depending on the tempering temperature. Steel is an alloy of iron with definite percentage of carbon ranges from 0.15-1.5%, plain carbon steels are those containing 0.1-0.25% . There are two main reasons for the popular use of steel: It is abundant in the earth’s crust in form of Fe 2 O 3 and little energy is required to convert it to Fe. It can be made to exhibit great variety of microstructures and thus a wide range of mechanical properties. Although the number of steel specifications runs into thousands, plain carbon steel accounts for more than 90% of the total steel output. The reason for its importance is that it is a tough, ductile and cheap material with reasonable casting, working and machining properties, which is also amenable to simple heat treatments to produce a wide range of properties [3]. They are found in applications such as train railroads, beams for building support structures, reinforcing rods in concrete, ship construction, tubes for boilers in power generating plants, oil and gas pipelines, car radiators, cutting tools etc. The objective of the present study is to investigate the effect of heat treatment (annealing, normalizing and quenching) on the mechanical properties of stainless steel. Abstract: In this paper, we study about the mechanical properties like Tensile strength and elongation for stainless steel. Author find out the effect of various heat treatment e.g. annealing, quenching and normalizing etc. on material properties through testing on samples using UTM. First of all, Metal rods are machined on lathe machine as per drawing of samples. Drawing is based on samples used for testing on Universal Testing Machine (UTM). Heat treatments are done in muffle furnace on 900 0 C and holding time is 2 hrs. Than cooled as per different heat treatment. After that heat treated samples are used for testing of different material properties. Result shows which heat treatment will be better for improving material properties of stainless steel. Keywords: Stainless steel; annealing; quenching; normalizing; tensile strength; yield stress; elongation; UTM