材料期刊网

本文针对CSP生产过程中SS400钢板产生的表面纵向裂纹进行研究与分析。结果表明：钢板表面纵向裂纹大部分分布在钢板宽度方向的两个1/4区域内，裂纹的长度一般在0.5-2m，深度为0.1-0.2mm,宽度均小于1mm。其裂纹沟内均含有由Na、Mg、Al、Si、Cl、K、Ca等元素组成的复合夹杂物相，而在裂纹的内部有氧化铁夹杂物。进一步分析后认为，该种表面缺陷产生于连铸结晶器内，在随后二冷区的强冷和加热炉的加热过程中，裂纹得到了进一步的扩展。通过对结晶器传热的控制和二冷水的调整, 板坯的纵裂得到了控制。

Surface longitudinal crack were studied and analized for SS400 steel sheet which occurred during CSP manufacture in this paper.The results demonstrated that most of the longitudinal cracks were distributed of 1/4 areas along the width direction of the steel sheet as parallel beam or reticulate form.The length and the depth of the cracks were 0.5-2mm and 0.1-0.2mm and the width was less than 1mm.Complex inclusions which composed of Na、Mg、Al、Si、Cl、K、Ca ets were found along the trench of the cracks, while only ferric oxide was found inside the cracks.Further analysis showed that such surface cracks originally formed in the successive mouldand further enlarged by the following secondary cooling and furnace heating. By controlling of the mould heat transfer and adjusting of secondary water cooling, longitudinal crack of steel sheet was controlled.