RO125538B1 - Process for preparing a soft magnetic alloy of the fe-co-v type with improved magnetic properties and magnetic alloy prepared thereby - Google Patents

Description

The invention relates to an alloy of the Fe - Co - (V) system and to a process for obtaining it, for the achievement of necessary benchmarks in the electrotechnical industry, for measuring equipment, electromagnetic circuits, magnetic amplifiers, etc.

Alloys are known from the Fe-Co and Fe-Co- (V) alloys with V percentages from 0.5 to 10%, made by classical flow, vacuum induction, hot and cold plastic deformation. , thermal treatment of stress relief and / or by metallurgy of powders, such as that of document JP 2002068514 (A), which has a magnetic alloy of Fe-Co with 10 ... 70% Co and at most 10% of at least one of the components: B, C, Al, Si, Ti, V, Cr, Mn, Ni, Cu, Zr, Nb, Mo, which has improved magnetic properties, allowing a high magnetic flux density.

Also, document JPH 07166239 (A) shows a process for obtaining Fe-Co-V alloy wires with 47 ... 53% Co and 1 ... 3% V by melting in protective atmosphere, plastic deformation at Warm, reheat the obtained wire at 850 ... 900 ° C in an inert gas atmosphere and water cooling, and JPS document 61130419 (A) shows an alloy type Fe-Co-V with 48 ... 52% Co and 1 ... 3% V, and a process for obtaining it by casting, heating at 700 ... 900 ° C, maintaining 0.5 ... 1 h and slow cooling, with maximum 100 ° C / hour.

Also known is JPH 01255645 (A), which has a Fe-Co-V type alloy with 40 ... 60% Co, up to 5% V, up to 3% Si, up to 3% Al and below 0.1% C, which may also contain one or more of the elements: Cr, Ni, Mn, Ti, Mo, Nb, W, Zr, and a process for obtaining it by means of heat treatment of solution to a minimum 950 ° C of the alloy obtained by melting with slow cooling and annealing to a minimum of 700 ° C.

The technical problem that the invention solves is to establish the parameters of some process phases for economical realization of an Fe-Co-V type alloy with improved magnetic characteristics.

The Fe-Co alloy - (V) according to the invention solves this technical problem by having 20+ 52% Co, 1.5 + 2% V, 0.5 + 1% Cr, Mn <0.5, Si < 0.7% and the rest Fe.

The process of obtaining the alloy, according to the invention, consists of elaboration in an induction oven at 1650 ± 20 ° C, under Ar protection, casting in metal shells at 1600 ± 50 ° C, homogenization in a flame oven at 1350 ± 20 ° C, hot plastic deformation by forging in the temperature range 1300 ± 50 ° C + 900 ± 50 ° C, with a total reduction rate of 82%, air cooling, final thermal treatment of stress relief at 850 ± 10 ° C , in an atmosphere of H ₂ .

The invention has the following advantages:

- the process produces a compact Fe-Co - (V) alloy, which leads to the increase of the magnetic characteristics;

- The Fe-Co- (V) alloy obtained has a homogeneous structure with large echiaxial crystals, generating improved magnetic properties.

The invention is further illustrated by an embodiment of the invention, in connection with FIG. 1 ... 3, which represents:

FIG. 1, technological flow for the realization of the soft magnetic materials from the Fe - Co system

- (V);

FIG. 2, table with values of the magnetic characteristics and the curve B _s ;

FIG. 3, microstructure of Fe-50% Co -2% V sample, in forged and heat treated state; (crystals of solid solution% attack: ferric chloride, magnification: x 800).

According to the invention, the claimed Fe-Co - (V) alloy comprises 20+ 52% Co, 1.5 + 2% V, 0.5 + 1% Cr, Mn <0.5, Si <0.7% and in addition Fe, and a homogeneous structure with large echiaxial crystals, which is favorable for the magnetic properties due to the small number of grain boundaries (fig. 3). The magnetic characteristics mentioned are the following:

- saturation induction: 23,000 Gs; - magnetic permeability: 8,000 at coercive field Hc = 1.5 Oe (fig. 2); - saturation field: Hs = 258 Oe.

RO 125538 Β1

The soft magnetic alloy from the Fe - Co (V) system is made, according to the process of claim 1, on the technological flow of fig. 1, by a mixture of the components of the Fe - Co - (V) alloy with 20- 52% Co, 1.5 - 2% V and the microalloying in the proportions specific to the alloy according to the 3 invention with Cr, Mn, Si, elements having a role of structural and advanced deoxidation modifiers of the metal bath obtained at a temperature of 1650 ± 20 ° C. 5

The casting of the alloy is made in metallic shells with a round section, with a ratio h / d> 5, at 1600 ± 50 ° C, followed by homogenization treatment at 1350 ± 20 ° C, one-way forging, 7 with a total reduction. greater than 82%, in the temperature range 1350 ±

20 ° C - 900 ± 50 ° C and air cooling. A final stress treatment at 850 ± 10 ° C is applied. 9

Claims (7)

1 Claims 3 1. Process for obtaining a soft Fe-Co-V type magnetic alloy with improved magnetic characteristics, mixed with a maximum of 52% Co melted in a protective atmosphere of 5 Ar, with hot plastic deformation at over 900 ° C after casting, characterized in that the melt mixture contains 1.5 ... 2% V, 0.5 ... 1% Cr, maximum 0.5% Mn and maximum 0.7% Si, 7 and it is melted in the induction furnace, the solid molded molding being hot plastic deformed with a reduction degree of more than 75% at 1300-5-900 ° C. 9 2. Fe-Co-V soft magnetic alloy with improved magnetic characteristics, with 20 -5- 52% Co and 1.5 -5-2%, characterized in that it contains 0.5-5-1% Cr, Mn <0.5 and 11 Si <0.7%, for obtaining a homogeneous structure with controlled grain size, which allows to obtain a high saturation induction, of 23,000 Gs, of a magnetic permeability of 13 8,000 in coercive field H _c = 1.5 Oe and of a saturation field H _s = 258 Oe.