管线钢起皮原因探讨

Discussion on the Crusting Causes of Pipeline Steel

通过金相观察、扫描电镜和EDS分析,对国内某钢厂生产的L245MB(B)管线钢出现的起皮缺陷进行了研究,发现连铸坯出现表面微裂纹且裂纹附近存在O、Si、Al、Ca和Cu元素的富集,确定铸坯中存在的氧化物夹杂及铜含量的超标引起的铸坯表面微裂纹是导致热轧卷板表面起皮的主要原因,钢的清洁度和连铸工艺是起皮的重要原因。分析了非金属氧化物、铜等低熔点金属及连铸工艺对铸坯表面微裂纹的影响机理,并由此提出了相应的防止措施。

By the observation and analysis of microstructures,SEM（scanning electron microscope） and EDS（energy dispersive X-ray spectrometry）,the hot rolled plate peeling defects of pipeline steel are studied.It shows that the microcrack is found on the surface of continuous casting slab,and the elements of O,Si,Al,Ca and Cu are enriched around the crack.The main reason for hot rolled plate surface peeling is the slab surface microcrack which is caused by oxide inclusions and copper content overproof.The steel cleanliness and continuous casting process can also be considered as important reasons.Finally,the influence mechanism of nonmetal oxide,the low melting point metal such as Cu and continuous casting process on the slab surface microcrack is discussed,and the preventive measures are presented correspondingly.