On-line Inspection Techniques for Surface Detects of Hot Slabs

Abstract

The steel industry has recently started the directly-linked steelmaking-rolling process in order to save energy. One of the techniques supporting this process is the hot slab surface flaw detection. Various methods have been developed to satisfy this need. So far, the optical method, eddy current one, and induction-heating one have been commercialized and are contributing to quality assurance of the continuously cast slabs in steel industry.
This paper presents the characteristic features of each method and also the detail of the induction-heating surface-flaw inspection system developed by Nippon Steel Corporation.