1.For the ω (Als ≤ 0.01% straight seam welded pipe, the use of two deoxidizer on the VD treatment of steel in the total oxygen impact is small, can be ω (T.O control in the 20 × 10-6 below; Si-Al-Ba deoxidation After the process can be a lower total oxygen content, the process of deoxidation effect is stronger than Si-Ca deoxidation effect.
2.When the Si-Ca and Si-Al-Ba two kinds of deoxidizer are used in the high-frequency straight seam welded pipe, the number and size of the inclusions in the smelting process are quite different. The number of inclusions in Si-Al-Ba Less than Si-Ca after deoxidation, and smaller size.
3.The inclusions in the forging material differ greatly from those in the aluminum inclusions. When the Si-Al-Ba deoxidation is used, the inclusions in the forging material are dominated by massive and chain alumina, and the high-frequency straight seam welded pipe uses Si-Ca deoxidation The contents of aluminum inclusions in Si-Ca alloy deoxidized forged materials are less than that of Si-Al-Ba alloy.
4.The length of the pipe is usually 4 to 10 meters, according to the length or double length of the factory. Steel pipe surface quality should be smooth, do not allow folding, cracks, stratification, welding and other defects exist. The surface of the pipe is allowed to have minor defects such as scratches, scratches, weld misalignment, burns and scarring that do not exceed the negative wall thickness. Allows weld thickening at the wall and the presence of internal welds.
