The surface of work rolls and back up rolls is worn out during hot rolling of heavy plates and strip steel because of micro structural changes and induced crack propagation. After the operation of the rolls in the mills, the surface will be regenerated by the following grinding process in the roll shops. This provides sufficient surface conditions for the next set in service. The roll shops of ThyssenKrupp Stahl will be gradually equipped with modern eddy current and ultrasonic techniques. The procedure for the implementation of these NDE techniques into the roll shop of a heavy plate mill will be described exemplarily. In the first step after bringing the installations into operational use, the former practice skills should be considered within the calibration of the systems. For this, the workmanship is documented by a statistical analysis of the signals obtained by these two non-destructive testing devices. Accordingly, the sensitivity of the operating systems is determined by comparing signals obtained from artificial notches with signals obtained from roll damages. These results are confirmed by taking micrographic examinations of the roll surface. After accurate confirmation of the relationship between the obtained signals and the condition of the rolls, the systems are fully set in service and integrated into the operation of the roll shop. This methodical approach contributes to a considerable benefit during the operation of the rolls since their service life is prolonged significantly.
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