Quality Control for Peritectic Steel Slab

摘要

In order to improve the internal and surface quality of peritectic steel slab, several factors were studied, such as the sulphur content in the liquid steel and the property of casting powder. Low sulphur content is helpful to reduce central segregation and internal crack, and to avoid seam crack formed on the slab surface caused by the segregation at grain boundary. During solidification of liquid steel, the volume shrinkage and short longitudinal crack occur due to peritectic reaction from S -ferrite to the tighter arranged gamma-austenite structure. It can be overcome by using proper casting powder with higher basicity, melting and crystallizing temperatures and low viscosity and controlling an accurate casting speed.