精密合金冷轧带材分层原因分析及冶炼工艺改进

Study on the Causes of the Lamination and the Improvement of Smelting Processing of Precise Alloy

针对1J79、4J6A冷轧钢带中存在的分层缺陷,采用扫描电镜、大样电解和定量金相等方法对铸锭和锻坯缺陷部位及分层的冷带坯和冷带试样进行分析检测。研究表明,铸锭、锻坯及冷带坯和冷带分层部位都存在大量以Al2O3为主的复合夹杂,尺寸很大,是造成分层的主导因素。通过采用延长钢包镇静时间,对返回料冶炼过程进行钙处理,真空冶炼后过滤浇注等措施,提高了钢质洁净度,使1J79冷带坯探伤废品率均值由原来的19.77%降至8.64%。

The lamination has been found in 1J79 and 4J6A cold-rolled steel strip.In this paper the aim is to find causes and to solve the problem by analysis and experimental research.The samples which cut from defect area of cast ingot,forge ingot,cold belts ingot and cold belts have been examined by scanning electron microscopy,bulk sample electrolysis and quantitative analysis.The main inclusion type is Al2O3 complex inclusion and the size of this type of inclusion is larger than others.It can be believed that the key factor of the lamination.So many technique measures have been taken including prolonging the killing time,changing the slag system and filtering casting and so on.The cleanliness of the material has been improved clearly and the probability of occurrence of lamination can be reduced.The defective index of 1J79 cold-rolled steel strip is reduced from 19.77% to 8.64%.