EVALUATION OF OVERLAY ON STAINLESS STEEL BY NDE METHODS
R. Subbaratnam, A. Baskaran and M. Palaniappan Quality Assurance Division, Technical Coordination & Quality Assurance Group Indira Gandhi Centre for Atomic Research (IGCAR), Kalpakkam 603 102, Tamil Nadu, India
The hardfacing or an overlay is recommended to enhance certain properties such as resistance to wear, corrosion or galling etc. depending on the service requirements. In the construction of fast reactors, many applications of stellite overlay on stainless steel are employed, either on inside or on outside surfaces of the components, to get the required hot hardness and to increase the metal wear resistance at high temperature services. This overlay requires high NDE sensitivity requirements as it is used in the inaccessible and high temperature environment. In the absence of international code/specification to meet the specific application requirements, a separate procedure which will meet the required sensitivity level, has to be established. The paper describes the usage of ultrasonic examination to establish the minimum debonding that can be detected and the procedures adopted to achieve the required sensitivity levels in defect evaluation.
Publication Source: Trends in NDE Science & Technology; Proceedings of the 14th World Conference on Non-Destructive Testing, New Delhi, 8-13 December 1996.Vol. 2, pages 401 - 404 Publisher:Ashgate Publishing Company
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