METHOD FOR THERMOMAGNETIC TREATMENT OF CYLINDRICAL ARTICLES FROM AUSTENITIC AND MARTENSITIC STEELS Russian patent published in 2024 - IPC C21D9/00 C21D1/04 C21D6/02 

FIELD: machine building.

SUBSTANCE: invention relates to machine building and is intended to improve operational characteristics of articles (workpieces) made from austenitic and martensitic steels. Invention is mainly used in structures and equipment used in oil and gas industry during oil and gas production and processing. Method for thermomagnetic treatment of cylindrical articles made from austenitic and martensitic steels involves heat treatment of articles by preheating to temperature of 900–1,500 °C with subsequent isothermal holding, then the articles are cooled to temperature of 450–550 °C in air with simultaneous exposure to constant magnetic field with magnetic field strength of not less than 19.6×10⁶ A/m, after which exposure to constant magnetic field is stopped and articles are completely cooled in air, wherein isothermal exposure is carried out for a time determined by the following formula:

,

where t is exposure time, min; d is the maximum diametral size of the article, mm; V_quen is steel quenching rate, mm/min; °t is heating temperature, °C; T_heat is the rate of through heating of the article to the specified temperature, °C/min.

EFFECT: improved operational characteristics of articles (workpieces) of steels of martensite and austenitic classes.

1 cl, 2 ex, 2 tbl