Stainless steel corrosion - A Case Study

Different parameters of localised corrosion of stainless steel have been studied with particular reference to failure of a stainless steel valve which was used in a pharmaceutical plant for handling the mixture of solvent and water. Results indicated that the attack was due to presence of a scale on the valve surface and due to abnormal inclusions in the metal. Stainless steel of 18:8 type freed from mill-scale and abnormal inclusions and higher grade steel e.g., A1S1 316L, were found to be resistant to such attack and were, therefore, considered as a better material of construction for the case referred to. (Shri K.P. Mukherjee and Dr. A.K. Lahiri, Scientists; and Dr. T. Banerjee, Scientist Emeritus, National Metallurgical Laboratory, Jamshedpur)