高强船板拉力分层原因分析及改进措施

Analysis on Causes Leading to Tensile Lamination in High Strength Steel Plates for Ship-building and Countermeasures

利用金相显微镜、扫描电镜和电子探针等手段对高强船板拉伸试验中出现的分层现象进行了分析,认为大量硫化物和氧化物夹杂、轧制后未轧合的孔洞以及C、Mn成分偏析造成的带状组织是导致拉力分层的直接原因。通过采取真空处理完毕后向钢液中喂入硅钙线、优化连铸工艺、优化加热及控轧控冷工艺等措施后,船板钢轧后探伤合格率明显提高。

The lamination phenomenon occurred in high strength steel plates tor ship-build- ing during tensile test is analyzed by such means as metallographic microscope, scanning electron microscope and electron probe microanalyzer. The results show that a large amount of sulphide and oxide inclusions, non zap-lop voids after rolled and the banded structure caused by composition segregation of C and Mn are the main causes leading to the tension lamination. After taking such measures as feeding silicon and calcium wires into molten steel after vacuum treatment, optimizing continuous casting process, optimizing the heating process and thermo-mechanical control process, the qualification rate of steel plates for ship-building during flaw detecting after finishing rolling is obviously improved.