镀锡带钢表面淬水斑形成机理及治理措施

Formation Mechanism and Treatment Measures of Quenching Water Spots on Surface of Tinned Strip Steel

针对镀锡机组带钢经过软熔淬水后带钢表面形成淬水斑质量缺陷问题,结合镀锡机组软熔工艺段设备的结构与特点,对带钢表面淬水缺陷进行检测,确定了淬水斑存在两种典型缺陷。在此基础上,根据克拉贝龙方程与沸腾传热理论,对带钢进入淬水槽的状态进行分析。分析结果表明,气泡在熔融锡层破裂产生的冲击力导致锡层分布不均匀或者杂质附着是淬水斑缺陷形成的主要机理。根据淬水斑形成机理,通过增设淬水槽喷嘴设备,稳定了带钢与淬水槽的温差,有效降低了带钢表面淬水斑缺陷的改判率,提高了镀锡板的市场竞争力。

In view of the quality defect of quenched water spot formed on strip steel surface after soft melt quenching of tin plating unit,combined with the equipment structure and characteristics of the soft melting section of the tin plating unit,the surface quenched water defect of strip steel was detected,and two typical defects of quenched water spot were determined.On this basis,according to Clapeyron equation and boiling heat transfer theory,the state of strip steel entering the quenched water tank is analyzed.The results show that the non-uniform distribution of tin layer or the adhesion of impurities caused by the impact force caused by the rupture of bubbles in the molten tin layer is the main mechanism for the formation of quenched water spot defects.According to the formation mechanism of quenched water spot,the temperature difference between strip steel and quenched water tank is stabilized by adding the nozzle equipment of quenched water tank,which effectively reduces the correction rate of quenched water spot defects on strip surface and improves the market competitiveness of tin plate.