Influence of casting parameters on void volume and centre segregation in continuously cast 100Cr6 blooms

AbstractContinuously cast ball and roller bearing steel 100Cr6 exhibits comparatively strong segregation which poses a quality handicap. In the present work which was carried out in the time between 1992 and 1996 the void formation which is related to the centre segregation and the centre segregation were measured on 2 m long segments of 240 × 200 mm2 blooms cast at the steel plant of Georgsmarienhutte GmbH. It was found that the segregation of carbon expressed with the ratio of C max/C o increases with casting speed and superheat. Many experiments were carried out to elucidate the effect of electromagnetic stirring along the lower part of the metallurgical length (F-EMS). But, unfortunately, a decrease in segregation could not be achieved by F-EMS. The only method to decrease the centre segregation in continuously cast blooms of 100Cr6 seems to be casting at low speeds with low superheat.