节镍型奥氏体不锈钢轧板表面脱皮缺陷的分析

Analysis of surface peeling defects on rolled plates of a nickel saving austenitic stainless steel

节镍型奥氏体不锈钢轧板常见的表面脱皮缺陷对产品质量有着极大的影响,并且一直是困扰企业生产经营的难题。由于其影响因素众多,迄今为止并没有得到根本的解决。采用金相显微镜、扫描电镜、荧光光谱仪对脱皮缺陷处的宏观形貌、微观组织及元素成分分析脱皮缺陷的形成原因。结果表明,表面脱皮缺陷为Fe、Mn、Cr的金属氧化物嵌入轧板基体造成的。不锈钢轧板脱皮缺陷一般来源于前工序轧板的隐性缺陷,这些缺陷在后工序生产过程中钢坯因加热不均或冷却不均可能出现微裂纹及高温氧化,从而表现为脱皮缺陷,形貌上包括条状型、舌头型脱皮或剥落型脱皮。通过改进连铸冷却工艺、减少废不锈钢兑入量、适当降低连铸拉速及改进热轧加热炉工艺,可有效降低表面的脱皮缺陷比例。

The frequently observed surface peeling defects on the Frolled plate of a kind of nickel-aving austenitic stainless steel have an extremely influence on product quality,and it has always been a difficult problem in the production and operation of enterprises.Because of its numerous influencing factors,it has not been fundamentally solved so far.The metallographic microscope,scanning electron microscope and fluorescence spectrometer were observed and analyzed the formation causes of peeling defects on the macroscopic morphology,microstructure and element composition of peeling defects.The results show that the surface peeling defects are result from Fe,Mn and Cr metal oxides embedded in the substrate of the rolled sheet The peeling defects of stainless steel rolling plate are generally derived from the hidden defects of the previous process of rolling plate rolling.These defects in the later process of production process may cause micro-cracks and high temperature oxidation of the billet due to uneven heating or cooling uneven,which are manifested as peeling defects,including strip peeling,tongue peeling or peeling peeling in morphology.By improving the continuous casting cooling process,reducing the amount of waste stainless steel,appropriately reducing the pulling speed of continuous casting and improving the hot rolling heating furnace process,the proportion of peeling defects on the surface can be effectively reduced.