METHOD OF PRODUCING ARTICLES FROM LOW-CARBON MARTENSITIC STEEL BLANKS (VERSIONS) Russian patent published in 2024 - IPC C21D8/10 C21D1/25 C21D1/78 C22C38/58 C22C38/48 C22C38/46 C22C38/44 

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy, namely to production of steel pipes of various technological purposes and other products of various industries from low-carbon martensitic steel blanks. Low-carbon martensitic steel is used containing the following in wt.%: 0.12-0.27 carbon, 1.5-3.0 chromium, 1.5-3.0 manganese, 0.8-1.5 nickel, 0.2-0.5 molybdenum, 0.04-0.2 vanadium, 0.04-0.15 niobium, in which the total content of chromium, manganese, nickel, molybdenum, vanadium, niobium does not exceed 5.7. Steel billet is subjected to double quenching and tempering. First quenching is carried out in the temperature range of 900-1,000 °C, then the first tempering is carried out at temperature of 400-700 °C, and then a second quenching is carried out in the temperature range of 750-850 °C. Then, if necessary, a second tempering is carried out at temperature of 180-680 °C.

EFFECT: wider range of values of physical and mechanical properties, as well as wider range of variation of operating parameters for use of pipes in various difficult operating conditions.

2 cl, 3 tbl