LAUSR

This study employed a digital evaluation approach for determining the nodule size of a no heat-treatment pearlite structure, as well as the grain size of the ferrite phase via an image morphology process methodology. The grain size of steel has great influence on the mechanical properties of manufactured materials, making it a necessary metallographic inspection item for materials. The properties affected by grain size include hardness, failure life, ultimate stress, electric characteristics, and heat expansion rate. In general, grain size inspection has two approaches: manual comparison and digital computation. In manual comparison, the comparison of standard graphics or the observation of an eyepiece inserted on a microscope can be progressed. For digital computation, planimetric and intercept procedures are applied according to international standards. This study thus applied an image processing algorithm to identify the observed image after undergoing seven times of erosion and dilation operations.