200系不锈钢热轧板边裂分析及控制

Analysis on Causes Leading to Edge Cracks of 200 Series Stainless Hot Rolled Steel Sheets and Control of Cracks

针对鞍钢联众(广州)不锈钢有限公司在生产200系不锈钢过程中,20LH和20L11两个品种经常出现边裂缺陷的问题,分析了边裂产生的原因。结果认为,铸坯加热制度不合理导致热塑性较差是热轧板边裂缺陷的主要原因。通过采取优化加热制度措施,即铸坯出炉温度从1 220℃降至(1 210±5)℃,铸坯在炉加热时间由260 min降至200-240 min,20LH和20L11不锈钢热轧板边裂比例稳定降至3%以下,铸坯质量得到改善。

In allusion to the problem that edge cracking occurred constantly in producing the200 series stainless steels such as these two steel grades of 20 LH and 20 L11 by Angang Lianzhong(Guangzhou)Stainless Steel Co.,Ltd.,the causes leading to the edge cracks were analyzed.The analytical results demonstrated that the main cause leading to edge cracks of hot rolled steel sheets was the bad thermoplasticity due to the unreasonable slab-heating system for casting blanks.After such measures for optimizing the heating system as reducing the temperature of casting blanks discharged out of a heating furnace to(1210±5)℃from 1220℃,and the time of heating casting blanks in furnace to the range of 200 minutes and 240 minutes from 260 minutes were taken,the ratio of edge cracks of stainless hot rolled steel sheets was stably reduced to less than 3%and therefore the quality of slabs was improved.