PIPE FOR GAS- AND PRODUCT PIPELINES AND A METHOD OF ITS PRODUCTION Russian patent published in 2005 - IPC

FIELD: metallurgy and mechanical engineering.

SUBSTANCE: the invention is pertaining to the field of metallurgy, in particular, to production of welded pipes for oil, gas- and product pipelines and other analogous designs (containers, pressurized cylinders) working in the difficult geologic, environmental conditions and in presents of aggressive corrosive mediums. The pipe for oil, gas- and product pipelines is made out of a steel smelt using the high-purity or pure charge materials bearing carbon, manganese, silicon, chromium, nickel, vanadium, niobium, titanium, aluminum, calcium, sulfur, phosphorus, nitrogen, copper, antimony, stannous, arsenic and iron and also molybdenum at the following ratio of components (in mass %): carbon - 0.02-0.11, manganese -0.10-1.80, silicon - 0.06-0.60, chromium - 0.005-0.30, nickel - 0.005-1.0, vanadium - 0.01-0.12, niobium - 0.02-0.10, titanium - 0.01-0.04, aluminum - 0.01-0.05, calcium - 0.0005-0.008, sulfur - 0.0005-0.008, phosphorus -0.001-0.012, nitrogen - 0.001-0.012, copper - 0.005-0.25, antimony 0,0001-0,005, stannous 0,0001-0,007, arsenic 0,0001-0,008, molybdenum - 0.001-0.5, iron - the rest. At that thus the total contents of nickel and manganese depends on a concentration of molybdenum and phosphorus in mass % in the following ratio: (Ni + Mn/1 + Mo)P <0.03. The method of production of the indicated pipe includes smelting of steel with the indicated composition, its treatment in a ladle, casting, hot rolling, molding and welding. The hot rolling is conducted by a reversing rolling mill or continuous rolling mills with the following controlled accelerated chilling.

EFFECT: the invention ensures increased efficiency of production of pipes for oil, gas- and product pipelines working in the difficult geologic, environmental conditions in presents of aggressive corrosive mediums.

2 cl, 2 tbl