Generally speaking, hot rolled seamless steel pipes can be used to produce oil casings, as well as welded pipe sets for welding. However, it is common to use welded pipe sets for welding in daily life. Due to the fact that there will be a weld in the oil casing produced by welding, issues such as matching the strength and toughness of the base metal with the weld, gray spots on the weld, and groove corrosion on the weld are issues that need to be addressed. When welding the oil casing produced by welding, attention should be paid to avoiding the above issues.
So what should be paid attention to when producing oil and casing pipes for welded pipe units? The welded pipe unit should pay attention to the strength and toughness when producing oil and casing pipes. The welded pipe unit can be cooled by controlled cooling after thermal tension reduction, which can greatly improve the weld problem of welded oil and casing pipes, and also enhance their strength and toughness. Factors such as the chemical composition of the welding base metal, welding temperature, and welding speed are the main factors that affect weld gray spots. To avoid weld gray spots, it is necessary to strictly control the edge quality of the strip steel and the welding process. The method of weld heat treatment and full tube heating before thermal tension reduction can be used to reduce and avoid the occurrence of weld gray spots. The control of weld groove corrosion needs to be avoided through thermal tension reduction.
