Effects of Steel Grade, Austenite Structure and Cooling Conditions on the Deformation of Square Section Bloom of Steel Cast Continuously and Stress Generation in the Bloom by Immersion Cooling

Abstract

In recent years, the treatment of inverse-transformation has been adopted in the HCR (Hot Charge Rolling) process of CC (Continuous Casting)-Blooming for steel production to prevent surface cracking on blooming. However, the quenching of bloom in this treatment occasionally causes some troubles, such as distortion of bloom and quenching crack. On the behavior of deformation of bloom and the generation of stress in cross section of bloom, the effects of cooling conditions of immersion cooling (quenching), steel grade and size of austenite grain were analyzed in order to prevent these troubles by the model of metallo-thermo-mechanics in this study. The results obtained from this analysis are as follows: The behavior of deformation of bloom and the distribution of stress in cross section of bloom by quenching is affected by steel grade and size of austenite grain caused by the difference in the distribution of amount of both diffusion and no diffusion transformation accompanying expansion and heat generation by latent heat in cross section of bloom.