管坯用钢P280GH分层缺陷鉴定及分析

Identification and analysis of delamination defects in steel P280GH for pipe

针对P280GH无缝钢管管坯穿管后出现分层缺陷,利用直读光谱仪、光学显微镜、扫描电镜、能谱仪进行分析,确定缺陷类型,同时查证生产过程,确定缺陷形成原因。结果表明:P280GH钢管中存在的分层缺陷,是因为成材率高,钢锭冒口切除不干净,滞留在钢锭冒口端的Al2O3非金属夹杂物在管坯轧制过程中,沿着轧制方向分布在钢管,形成分层。

In response to the delamination defect of P280GH seamless steel pipe blank after threading,direct reading spectrometer,optical microscope,scanning electron microscope,and energy spectrometer were used to ana-lyze and determine the type of defect.At the same time,the production process was verified to determine the cause of defect formation.The results indicate that the delamination defect in P280GH steel pipe is due to the high yield rate and inadequate removal of the steel ingot riser.The Al2O3 non-metallic inclusions trapped at the riser end of the steel ingot are distributed along the rolling direction during the pipe blank rolling process,forming delamination in the steel pipe.