Effects of Mould Oscillation Conditions on Oscillation Marks of Stainless Steel Casts

Abstract

Oscillation marks formed on the surfaces of continuously cast stainless steel slabs are one of the factors that hinder the use of unconditioned slabs. Therefore, the effects of mould oscillation conditions on oscillation marks have been investigated using a Continuous Caster Mould Simulator.
Following results have been obtained through the experiments.
1) A crescent-shaped extended surface is formed in the valley of an oscillation mark on a SUS 304 solidified shell and an unusual solidified structure is generated in the upper part of this extended surface. The unusual solidified structure is found to be a layer of Ni-segregation.
2) When the negative strip ratio is positive, the shorter the heal time ((θ_h), the shallower the oscillation mark depth.
3) Oscillation marks are formed even at θ_h-0 and when the negative strip ratio is negative, the shorter the stroke, the shallower the oscillation mark depth.