ONLINE-CONTROLLED SEAMLESS STEEL TUBE COOLING PROCESS AND SEAMLESS STEEL TUBE MANUFACTURING METHOD WITH EFFECTIVE GRAIN REFINEMENT

摘要

A seamless steel tube with high strength and toughness, comprising the following chemical elements by mass: 0.1-0.25% of C, 0.1-0.5% of Si, 0.01-0.1% of Al, 0.6-2% of Mn, the balance of Fe and other unavoidable impurities, wherein C+Mn/6‰¥0.35. Also provided is a method for preparing a seamless steel tube.