Quantifying carbide particles in steel by image processing method
KAWAKAMI, Hiroshi TAMAKI, Koreaki TAKAHASHI, Kanta
川上, 博士 玉置, 維昭 高橋, 寛太
三重大学工学部 三重大学工学部 三重大学工学部 Faculty of Engineering, Mie University Faculty of Engineering, Mie University Faculty ofEngineering, Mie University
Faculty of Engineering, Mie University
Research reports of the Faculty of Engineering, Mie University
image processing shape of carbide particle SR embrittlement SEM image 2 1/4Cr-1Mo steel cleavage fracture
SR embrittlement srises in HAZ of 2 1/4Cr-1Mo steel by the long-time reheating in SR treatment. The behavior of carbide particle seems to have close relation with SR embrittlement, as they grow significantly in the time range of SR embrittlement. The number of carbide particles which observed on the fracture surface of the specimen suffered from SR embrittlement is larger than that in cross-section. The systematic investigations may be needed to discuss the role of carbide particles on SR embrittlement. In this study, the size and shape of carbide particle were measured systematically by using the image processing. The experimental system for quantifying of carbide particles is combined with scanning electron microscope (SEM) and a personal computer. The suitable method of image processing which can recognize the shape of carbide particles in the image by SEM was established in the fast place. The size of carbide particle in cross-section increased with an increasing time of SR treatment. The shapes of carbide particles in cross-section changed from sphere to elliptical with the growth of particle. But the relation between the size and shape of carbide which was observed on fracture surface was different from that in cross-section when SR embrittlement occurs significantly. The fractured carbide particles were observed on fracture surface. This result suggests that the crack propagation in carbide particles helps to occur SR embrittlement.