The main objective of the work is to present the entire scope of sensitization of stainless steel pertaining to environmental effect. The work starts with a continuum description of stainless steel, extends this background to the types of attack in stainless steel and then considers the major practical analysis of the topic conforming to the laboratory testing. The entire procedure of the testing has been pursued based on Standard practices for detecting susceptibility to Intergranular attack in austenitic stainless steels - ASTM A262 - 02A. All of the experiments has been done in the laboratory & workshops of Metallurgical Enginering of Bengal Engineering & Science University, Shibpur. Nos of research topics related to the corrosion investigation of S.S, have been studied thoroughly and taken the guidance of the achievers triumph.