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).