Development of Automated Spark Testing Technique by Image Processing to Measure Carbon Content in Steel Materials

Abstract

The spark testing is a method to determine the classification of the steel materials from the characteristics of sparks emitted by the grinding wheel. This spark testing is used because it is quick, easy and inexpensive. And it especially could determine carbon content in an instant. However, the mastering of this spark testing is very difficult, unstable and there is individual difference to identify the steel materials. So, strict management of the steel materials was expected by realization of automated spark testing technique which has no individual difference and high stability to confirm process. The automated spark testing technique which we developed for determining the carbon content was consisted of automatic grinder, high speed camera of per second 200 images and high speed image processing computer. Result showed that the carbon content measurement accuracy is about ±0.05% in carbon steel. This would mean that this automated spark testing technique is very precise, and has potential for practical use. Therefore, strict management of the steel materials could be realized by this automated spark testing technique.