LOW-CARBON MANGANESE STEELS PIPES HEAT TREATMENT METHOD Russian patent published in 1995 - IPC

FIELD: mainly pipes of oil products range. SUBSTANCE: low-carbon (C 0.17 0.35 mass) manganese (Mn + 0.35 1.20 mass) steels pipes heat treatment method provides for cooling after passing last stand of rolling mill in air down to the shop temperature. Heating up to temperature of 760 790 C is exercised with water cooling down to the shop air temperature and additional heating up to temperature of 670 - 700 C is exercised with following cooling in the air. The procedure takes off inner tensions, prevents spheroidization of carbides, increases pipes resistivity to sulfide corrosion cracking. EFFECT: increased pieces resistivity to sulfide corrosion cracking under tension in mediums with low concentration of natural and bacterial hydrogen sulfide. 1 tbl