Patent ID: 8761444

Claim:
An apparatus for determining the kind of a steel material, comprising: an image pickup device for imaging a spark, which is produced when the steel material is ground, continuously a plurality of times; a detection device for detecting an alloy spark zone, which corresponds to an alloy spark produced by the grinding of an alloying component contained in the steel material, from each of picked-up images imaged by the image pickup device; a calculation device for calculating the total number of alloy spark zones by summing up the number of alloy spark zones of each picked-up image detected by the detection device for all of the picked-up images; and a judgment device for determining that the steel material consists of a low-alloy steel if the total number is not smaller than a first threshold value, and determining that the steel material consists of a carbon steel if the total number is smaller than the first threshold value, wherein the detection device performs: first processing in which a spark candidate pixel group consisting of pixels which are continuous with each other along a pixel line and have a density not lower than a second threshold value is detected for one pixel line constituting each of the picked-up images; second processing in which a highest density of pixels constituting the spark candidate pixel group is detected, and the pixels constituting each of a plurality of spark candidate pixel groups are binarized by a third threshold value which is lower than the highest density and larger than the second threshold value, whereby the pixels constituting a spark pixel group are detected from the pixels constituting each of the plurality of spark candidate pixel groups; third processing in which a binarized image representing the spark pixel group is prepared by executing the first processing and the second processing for all of the pixel lines constituting each of the picked-up images, and the spark pixel group continuous on the binarized image is recognized as a spark zone corresponding to a spark produced when the steel material is ground; and fourth processing in which the alloy spark zone is detected from the spark zone recognized by the third processing.