Steels for rail-making involve standard requirements concerning oxide cleanness. Castability problems do not generally occur. Due to the extremely high demands on cleanness, roller-bearing steel 100Cr6 is cast using narrow SENs, which are extremely susceptible to clogging. Problems caused by clogging occur despite the tact that these heats are deoxidized using C, Si and Mn, with no addition of Al. Castability improved significantly after conversion to low-Al ferrosilicon for deoxidation and rinsing of ladles with carbon-deoxidized preceding heats. Casting temperature with a superheat of 30 deg C and a reduction in Al content to less than 20 ppm made it possible to increase sequence length to three heats.
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