Analysis on the Characteristics and Origin of Surface Net-shape Cracks on Steel Sheet
ZHU Guihe
JIANG Xuejun
Abstract：In order to find out the reason of the cracks and solve the problem of surface cracks on sheet, this article analyzed the characteristics of surface net-shape cracks on SM490A, AH32 and E grade hull sheet. With the help of electronic microscope, spectrum analysis and metallographic analysis, the organization around the cracks are carefully examined. The results showed that together with the oxide of Fe, Ca, Al of cast slag, there’s some other oxide dots and Cu particles;On the surface side of the crack there’s a visible decarburization area, banded structure doesn’t show too much there, while on the other side of the crack, they are apparent;Secondary oxide particles around the crack organization are heavy. So the cracks are supposed not created during the rolling process, but are caused from casting. A more careful mould manual regulation is set up, it improves protecting slag and liquid steel quality, and hot changing system. After the change, this defect is completely erased.
Keywords：sheetnet-shape crackingscanning electron microscopesecondary oxide particleslab crack
Publication Date：2014-03-02
Online Publishing Date：2026-05-22(First online date of this platform, not the publication date of the document)
Pages：5( 22-25,28 )