METHOD OF PRODUCING MAGNETIC CONDUCTOR WORKPIECE FOR ELECTROMAGNETIC RELAY, METHOD OF PRODUCING MAGNETIC CONDUCTOR FROM SAID WORKPIECE Russian patent published in 2025 - IPC H01F1/22 B22F3/12 

FIELD: powder metallurgy.

SUBSTANCE: invention relates to powder metallurgy, namely to a method of producing magnetic conductors of electromagnetic relays, in particular, relays of railway automatics and telemechanics of NMSh, REL and N. Objective of the proposed technical solution is to develop a technology for manufacturing a magnetic conductor for electromagnetic relays of railway automatics and telemechanics with high operational properties. Mixture is prepared by adding into powder of iron containing not more than 0.03 wt.% carbon and not more than 0.15 wt.% oxygen and phosphorus in the form of a solution of orthophosphoric acid H₃PO₃ or ferrophosphorus powder to ensure the phosphorus content in the mixture in amount of 0.5-1.5 wt.%, pressing is carried out in hard-alloy moulds at one-side load of 700 MPa at load of 6-8 t/cm², sintering of workpieces is carried out at temperature of 1,160-1,200 °C in a furnace in an endothermic gas environment. According to the invention, after sintering, the workpiece is subjected to thermal annealing in vacuum of 10^-1-10^-2 Pa, at temperature 1,260-1,320 °C at a heating rate of 500-600 °C/h, holding for 2.5-4.0 hours, then cooling to temperature of 850-910 °C, at speed of 500-700 °C/h, then cooling, at rate of 40-60 °C/h, up to temperature of 300-370 °C, and final cooling together with furnace to ambient temperature, after mechanical treatment, thermal annealing of the magnetic core is carried out in vacuum of 10^-1-10^-2 Pa, at temperature of 900-1,000 °C, at a heating rate of 500-600 °C/h, holding for 2.5-4.0 hours, then cooling, at rate of 40-60 °C/h, up to temperature of 300-370 °C, and final cooling together with the furnace to ambient temperature.

EFFECT: increased magnetic permeability, reduced coercive force and saturation induction of powder magnetically soft material.

8 cl, 3 dwg, 1 tbl, 3 ex