Abstract: The examination and analysis on thickness, structure and composition of surface residual oxide scale of Φ14mm and Φ16mm coii of spring steel (/%：0.58C, 1.66Si, 0.78Mn, 0.006P, 0.004S) have been carried out by using optical microscope and scanning electron microscope. Results show that with eutectoid reaction of Si in spring steel and FeO to form fayalite (2FeO·SiO₂) produced pinning effect on oxide scale and higher cooling speed of coil after rolling and thicker decarburization layer of coil lead to difficultly remove the oxide scale by picking process. With decreasing heating furnace soaking temperature to 1050℃;from original 1150℃ , heating time no more than 2h, controlling residual oxygen content in furnace ≤2% , decreasing finishing rolling temperature from original 920℃ to 870℃ and end rolling temperature from 880°C to 840°C to avoid occurring full decarburization layer to lighten and avoid to form fayalite ( 2FeO·SiO₂) , descaling water pressure ≥14MPa and decreasing average cooling speed from 1.9°C/s to 1.6°C/s to make partial FeO transformation, expanding and cracking, the picking effect markedly improves. Results show that after process improvement the picking defect ratio of oxide scale decreases from original 2.91%~3.58% to 0.69%~1.65%.

摘要： 利用光学显微镜和扫描电子显微镜对Φ14mm和Φ16mm弹簧钢盘条（/%:0.58C,1.66Si,0.78Mn,0.006P,0.004S）表面残留氧化铁皮的厚度、结构及成分进行测量和分析。结果表明,弹簧钢中Si与FeO发生共析反应,生成铁橄榄石（2FeO·SiO₂）对氧化铁皮的钉扎效应以及较高的冷却速度、较厚脱碳层,会造成酸浸后氧化铁皮难以去除。通过将加热炉均热温度由原1150℃降至1050℃,加热时间不大于2h,控制炉内残氧量≤2%,精轧温度从920℃降至870℃,终轧温度从880℃降至840℃,避免出现全脱碳,减轻和避免生成铁橄榄石（2FeO·SiO₂）,除鳞水压≥14MPa,并平均冷却速度从1.9℃/s降至1.6℃/s,使部分FeO发生转变,产生体积膨胀和氧化铁皮开裂,改善酸洗效果。结果表明工艺改进后氧化铁皮酸洗缺陷率由原2.91%~3.58%降至0.69%~1.65%。

关键词: 弹簧钢盘条, 氧化铁皮酸洗残留, 光学显微镜, 扫描电镜, 铁橄榄石, 脱碳层