高强度船板表面花斑缺陷的形成机制及改进措施

基于金相分析和气泡试验，分析了高强度船板表面花斑缺陷的形貌特征和微观组织，研究了化学成分、轧制工艺对花斑缺陷的影响。结果表明：花斑缺陷的形成原因主要是二次氧化铁皮在轧制过程中被压入钢板基体，导致钢板表面形成厚度差异较大的氧化铁皮，钢板抛丸后形成凹凸不平的斑状缺陷。通过降低钢中硅含量、优化高压水除鳞方式、低成本改进高压水除鳞系统，有效控制了高强度船板表面花斑缺陷。

Formation mechanism and improvement measures of granophyric defect on the surface of high strength ship plate

The morphology characteristics and microstructure of the granophyric defects on the surface of high strength ship plate were analyzed based on metallography analysis and bubble test.The effects of alloy composition,rolling process on this defect were investigated.The results showed that the secondary iron oxide was pressed into the steel plate surface in the rolling process,which led to the formation of iron oxide with large different thickness on the plate surface,after shot blasting the uneven granophyric defects formed on the plate surface.The granophyric defects were controlled by lowering Si content,optimizing high-pressure water descaling method and improving the high-pressure water system with low cost.