The formation mechanism for transverse surface crack of continuous casting slabs is analyzed and delved from three aspects- No3 brittle zone

oscillation mark and segregation. It is obtained that the brittlement of steel at No3 brittle zone is not enough to explain the formation of transverse surface crack

the segregation and the factors leading to stress concentration such as oscillation marks and inclusions are also taken into account. On this studied basis the measures to prevent the transverse surface crack of slab are discussed and simply summarized including controlling casting slab straightening temperature

precipitates at grain boundary

cooling rate at secondary cooling zone and C% in low carbon steel; improving oscillation amplitude and taper of mold

and mold powder； decreasing S and P content in steel

increasing Mn/S

decreasing cooling speed at mold meniscus and improving mold surface roughness factor.