Shimal Khan

Characterization of Cold Rolled Austenitic Stainless Steel by Ultrasonic Longitudinal Velocity

Ultrasonic testing has a strong application in defect detection. An efficient tool for characterizing and life assessment of material structure and components by nondestructive ultrasonic velocity was developed about thirty years ago. Cold rolling results in increase in strength and hardness. The work discussed here is to study quantitative ultrasonic longitudinal velocity for characterizing a change in microstructure due to cold rolling in austenitic stainless steel samples. Samples were cold rolled upto 80 percent in 10 percent step. It was found that the use of velocity measurements is a useful quantitative and non-destructive tool for characterizing amount of cold rolled austenitic stainless steel.

Metallurgical Characterization of Duplex Steel by Non Destructive Techniques

This paper describes the application of eddy current and ultrasonic velocity technique for the study of cold rolled duplex steel. Samples are cold rolled up to 80 percent and then tested for X-Ray diffractrometeric analysis, hardness testing, ultrasonic longitudinal velocity and for eddy-current testing. It was observed that eddy current impedance and longitudinal velocity is affected due to variation in micro-structure induced by cold working. It is suggested that eddy current and ultrasonic velocity techniques are useful tools for the characterization of duplex steel during cold working operation.

Evaluation of Phase Transformation in Manganese Steels by Eddy Current Method

An investigation was conducted to explore the applicability of eddy current nondestructive evaluation technique for the characterization of manganese steels. Specimens of two different types of manganese steels were subjected to various compression loads. The specimens were then evaluated by mechanical and eddy current testing. The hardness and eddy current values were increased due to conversion of austenite to martensite. In this study the correlation between eddy current parameters and compression load was discussed.