中厚板表面微裂纹成因及影响因素研究

对重钢连铸板坯轧制中厚板出现的表面微裂纹进行取样,经低倍检验发现,微裂纹有3种类型;与之对应的连铸板坯酸洗后发现,微裂纹也有3种类型,采用镀层结晶器铜板前以网状裂纹为主,尔后以横裂纹为主;对裂纹量最多的网状裂纹进行高倍和能谱检验,发现网状裂纹主要是铜裂纹.分析产生裂纹炉次的对应工艺,找出其主要影响因素是结晶器铜板、结晶器保护渣、二次冷却制度、钢中的w(N)等,针对性地采取预防措施,使中厚板表面微裂纹大幅度减少.

Formation and Factors of Surface Micro Cracks of Plate

The plate samples with surface micro cracks rolled from continuously cast slab were investigated by microscopic examination, and it was found that there were three types of surface micro cracks, then on the corresponding pickled slabs. There were mainly reticular cracks on slabs cast with original mould, but mainly transverse cracks on slabs east with plated mould. According to macroscopic examination and energy spectrum analysis for reticular cracks, the cracks were caused by copper. By analyzing the relevant technology, the main influential factors about surface micro cracks of are as follows., the mould copper plate, continuous casting mould fluxes and secondary cool ing system, nitrogen in the steel, etc. By taking effective prevention measures, the amount of surface micro cracks on plate is decreased.