2019 Volume 59 Issue 1 Pages 93-97
Shape defect such as bow and crossbow, is one of the major defects in hot rolled sheets. These defects arise due to non-uniform plastic strain (thermal and mechanical) due to improper rolling process. In-turn this non-uniform strain induces residual stress in the rolled material. Hence measurement of residual stress in early stage helps as a Go/No Go tool, while supplying material to customers to whom shape defects are very much problematic during its downstream process. In this paper a non-destructive testing (NDT) technique has been developed to predict the magnitude of bow/crossbow based on residual stress measurement using ultrasonic technique. The technique employs the relationship between residual stress distribution and its corresponding effect towards bow/crossbow formation. The paper also elaborates about residual stress measurement using ultrasonic measurement based on the acousto-elastic theory. It was demonstrated that there exists a distinct relationship between crossbow and residual stress for high strength hot rolled steel sheets experimentally.