Surface segregation is often found to occur on oscillation marks of continuously cast austenitic stainless steel slab surface. The actual state of surface segregation and the effect of oscillation conditions on them have been investigated in order to make clear the formation mechanism of surface segregation.
1) Surface segregation occurs only in the valley of osillation marks and two typical forms, over-flow type and mini-bleed type, are observed.
2) Surface segregation is composed of bands of enriched solutes, (Ni), (Mn), (Si), (P), etc.
3) The shorter the negative strip time (t_N) is, the smaller the freqency of occurence and depth of surface segregation become.
4) It is considered that the formation mechanism of surface segregation can be explained by over-flow and bleeding-out of solute enriched molten steel into oscillation marks of slab surface.