CAJ | 학술논문

为找出裂纹来源，解决钢板表面裂纹问题，对SM490A、AH32及E级船板等钢板表面的网状裂纹形貌特征进行分析，并对其周围组织进行电镜、能谱分析及金相分析，结果表明，裂纹底部除存在Fe、Ca、Al的氧化物（保护渣成分）外，还存在氧化物圆点、Cu质点；裂纹近表面一侧有明显的脱碳区，带状组织不明显，而裂纹另一侧呈现明显的带状组织形貌；裂纹周围组织中存在大量的二次氧化颗粒。认为裂纹不是在轧制过程中产生的，是铸坯中就存在。通过制定严格的结晶器使用管理规定，改善保护渣及钢水质量、热装制度等，彻底消除了该类缺陷。
위조출렬문래원，해결강판표면렬문문제，대SM490A、AH32급E급선판등강판표면적망상렬문형모특정진행분석，병대기주위조직진행전경、능보분석급금상분석，결과표명，렬문저부제존재Fe、Ca、Al적양화물（보호사성분）외，환존재양화물원점、Cu질점；렬문근표면일측유명현적탈탄구，대상조직불명현，이렬문령일측정현명현적대상조직형모；렬문주위조직중존재대량적이차양화과립。인위렬문불시재알제과정중산생적，시주배중취존재。통과제정엄격적결정기사용관리규정，개선보호사급강수질량、열장제도등，철저소제료해류결함。
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.