Cause analysis of flaw detection unqualified of 4130X continuous casting open cast furnace steel pipe
ZHANG Xinwen1, SHI Jiakai2, ZHANG Chunxiang1, CHEN Kai1, XUAN Kangle1
1. Special Steel Company, Jiangsu Yonggang Group Co., Ltd., Suzhou 215628, China; 2. Product R & D Center, Jiangsu Yonggang Group Co., Ltd., Suzhou 215628, China
Abstract：It pointed out that the reason for flaw detection unqualified of 4130X steel pipe was the nonmetallic inclusions caused by secondary oxidation of open cast furnace. Take ø500 mm continuous casting blank as the object, several samples were taken from different positions of the casting blank. It was found that the oxygen content, nitrogen content, Al loss and nonmetallic inclusions in the steel in the open casting part were higher than those in other parts, which implied that the secondary oxidation in the open casting part was more serious. In addition, the nearlier to open casting part the quantity and distribution density of inclusions with length more than 5 μm. It is indicated that the effect of secondary oxidation on inclusions more then 5 μm is obviously when open casting.
2023, Vol. 41 
