Automatic inclusion classifier for quality control in the steel industry

The information required from an assessment of nonmetallic inclusions in steel is detailed. Particular reference is made to the Jernkontoret system. A need exists for an instrument which provides this information in a form and timescale which is adequate for some control to be exercised during the production stage. Possible approaches are outlined, and some advantages of the chosen system are enumerated. This system is based on an analysis of the electrons backscattered from the point of impact of a scanned electron microprobe. The principles and main functional elements of a prototype instrument, which includes all facilities from programming to printout, are described. Some of the inherent limitations of the system are discussed, and the measured instrumental performance, including reproducibility, is detailed. Preliminary results of measurements on typical steel samples are compared with those obtained by chemical analysis and optical assessment. Alternative presentations or processing of the output information is considered.