R&D of Gr6 Low Yield Ratio Seamless Steel Pipe for Low Temperature-service Piping

Presented here in the article is the manufacturing method for the Gr6 low yield ratio seamless steel tube for low temperature-service piping，involving such main aspects as the chemical composition design，and the manufacturing process flows of melting， rolling and heat treatment. The workpiece deformation is fulfilled in low temperature section of the individual item zone by means of properly adjusting the chemical composition of the tube， and controlling the final-rolling temperature. Relevant test results show that the seamless steel tube for low temperature-service piping as produced with the above mentioned method is in possession of yield ratio≤0.72，and the mechanical properties and low temperature impact toughness as completely meeting the requirements under specification ASTM A 333/A 333M—2013.