Study on hot tearing tendency during continuous casting of steel by overall hot tearing susceptibility (OHTS)

Abstract

In this work, a new criterion for estimating hot tear susceptibility called overall hot tearing susceptibility (OHTS) is proposed to determine hot tearing tendency in the mould region during continuous casting. The OHTS criterion takes into account the cooling rate, brittle temperature range, strain rate and thickness of the brittle region. For estimating these parameters, a solidification model along with a microsegregation model, was developed. Using OHTS, the effects of carbon content, casting speed, pouring temperature and mould level on the hot tearing tendency of steel bloom were evaluated; and it was concluded that, raising the cooling rate and reducing the thickness of the brittle region increase the tendency of hot tearing. Raising the brittle temperature range tends to decrease the critical strain, so an increase in OHTS occurs; and to decrease the strain rate causing an increase in critical strain and as a result the OHTS is reduced.