Abstract: The ingredients,characteristics and forming accounts of typical defects - scale-shaped outer-overlap,entraped slag outer-overlap and dregs pit of steel 36Mn2V N80 oil pipe were analyzed. The occured rate of N80 oil pipe typical defects decreased to less than 2% from 5%~6% and tube product yield increased to 86.65% from 82.20% by controlling  end[C]≥0.05%,LF[Al]0.02%,slagging  amount  during  tapping  and  constant  liquid  steel  level  in  tundish(≥  600  mm).

Key words: N80 , Oil , Tube, Steel , 36Mn2V, Defect, Inclusion, Control , Measure

摘要： 分析36Mn2V钢N80级油管的典型缺陷———鱼鳞外折、夹渣性大外折和渣坑的组成、特征和形成原因,通过控制钢水终点[C]≥0.05%,LF钢水[Al]为0.02%,有效进行钙处理,控制下渣量,稳定中间包钢水液面≥600 mm,使N80油管典型缺陷出现率由5%~6%下降到2%以下,成材率由82.20%提高至86.65%。

关键词: N80油管, 36Mn2V钢 , 缺陷 , 夹杂物, 控制措施