冷轧含磷IF高强钢带表面氧化色缺陷控制

Control of surface oxide defect cold-rolled phosphorus-bearing IF high strength steel strip

采用EPMA、EDS对CSP工艺生产440 MPa冷轧含磷IF高强钢带表面氧化色进行了研究,分析氧化色形成原理,讨论了罩式炉退火气氛、合金元素对氧化色形成的影响。结果表明,降低钢中Mn、Ti并含量添加微量的Nb、Si,退火初期采用120 m^3/h氮气吹扫,并在550~180℃进行冷却时增加氢气吹扫,冷轧板形采用微边浪模式均可抑制氧化色的产生,同时降低生产成本3.7%。

The surface oxide defect of 440 MPa cold-rolled IF high strength steel containing P by CSP process was studied by using EPMA and EDS. The generation mechanism of oxidation,the effects of BAF annealing atmosphere and alloying element on the formation of oxidation were discussed. The results show that some control measures can prevent the generation of oxide defect greatly and reduce the production cost3. 7%. These control measures include reducing the content of Mn,Ti,adding Nb,Si trace,using 120 m^3/h N_2 purge during the early stage of annealing and increasing the H_2 purge in the 550-180 ℃ cooling stage,and micro wave pattern is used for cold rolled strip shape.