IRON-BASED ALLOY AND A METHOD OF PRODUCTION THEREOF Russian patent published in 2004 - IPC

FIELD: ferrous metallurgy.

SUBSTANCE: invention relates to hard-magnet alloys for constant magnets, which are employed in motor car and aircraft construction, instrument-making industry, electric engineering, etc. more specifically, invention provides iron-based hard-magnet alloy containing, wt %: carbon plus nitrogen up to 0.05, cobalt 7.0-8.0, chromium 27.0-29.0, ferrite-forming alloying additives: silicon 0.5-0.8, vanadium 0.2-0.5, and titanium 0.3-0.5. Alloy is first subjected to homogenization, then heated to 700-720^оС, cooled in magnetic field and then without magnetic field. Cooling in magnetic field is effected within temperature range 640-620^оС at the cooling rate no higher than 0.1^оС/min and subsequent tempering proceeds at 500^оС during 20-24 h. After thermomagnetic treatment, alloy has residual induction B= 1.28-1.30 Tl, coercive force H = 42-44 kA/m, and maximum energetic product (BH)_max = 36-38 kJ/m³.

EFFECT: retained high level of magnetic properties at lower cobalt content.