Q355C带钢表面翘皮产生原因及解决措施

Causes and solutions of surface warping of Q355C strip steel

在生产Q355C热轧带钢过程中,发现带钢表面频繁出现翘皮缺陷。为此,对存在翘曲缺陷的带钢进行了金相和气体检测,对再热处理的连铸坯进行了热酸侵蚀检测和裂纹分析。本文从炼钢工序、精炼工序、连铸工序、热轧工序以及连铸坯进入加热炉的温度等方面分析了带钢产生翘皮的原因,结果表明Q355C热轧带钢翘皮的产生与钢中氮元素含量过高、入加热炉板坯温度过低有关。通过优化转炉装料制度、调整转炉底吹模式、提高转炉终点碳元素含量和温度、优化LF埋弧冶炼效果、钢包长水口吹氩保护浇注和提高连铸坯入加热炉温度等手段,使翘皮缺陷基本得到消除。

In the process of producing Q355C hot rolled strip steel,it was found that the surface of strip steel frequently appeared warping defects.To this end,the metallographic and gas inspection for the strip steel with the warping defects are carried out,and the hot acid corrosion inspection and crack analysis for the continuous casting slab of reheating treatment are carried out.This paper analyzes the causes of strip steel production warping from the aspects of steelmaking process,refining process,continuous casting process,hot rolling process and continuous casting slab temperature of coming into the heating furnace,the results show that the occurrence of Q355C hot rolled strip steel warping is related to the high nitrogen element content in the steel and the low continuous casting slab temperature of coming into the heating furnace.Through optimizing the charging system of the converter,adjusting converter bottom blowing mode,increasing carbon element content and temperature at the finishing point of converter,optimizing LF submerged arc smelting effect,argon blowing protection casting of ladle long nozzle and increasing continuous casting slab temperature into the heating furnace,the warping defects of strip steel are basically eliminated.