Magnetic control mechanism magnetic shell material and preparation method thereof

Abstract

The invention discloses a magnetic control mechanism magnetic shell material and a preparation method thereof, and belongs to the technical field of power distribution equipment, and the magnetic control mechanism magnetic shell material comprises the following chemical component element proportions (%): 0.5-0.55% of C; 6.0 to 8.0% of chromium (Cr); 0.20 to 0.25% of nickel (Ni); 0.60 to 0.80% of Si (silicon); less than or equal to 0.035 of phosphorus P; mn: less than or equal to 0.1; and the balance of Fe. The preparation method comprises the following steps: weighing raw materials and preparing; mixing the raw materials, and forging a blank to obtain a steel ingot; machining the steel ingot, and machining the steel ingot into the shape required by the magnetic shell according to the design size, so as to obtain a preliminarily formed magnetic shell; and performing heat treatment on the preliminarily formed magnetic shell to obtain the magnetic shell of the magnetic control mechanism. According to the magnetic shell, the saturation flux density, the residual magnetism and the alloy coercive force of a machine body are improved, the strength, the hardness and the corrosion resistance are improved, the magnetic shell material is a low-alloy carbon steel system, the alloy cost is low, and the magnetic shell can be widely popularized in the technical field of power distribution switch equipment.

Description

Technical Field

[0001] The invention belongs to the technical field of power distribution equipment, and in particular relates to a magnetic shell material of a magnetron mechanism and a preparation method thereof. Background Art

[0002] The magnet housing of the magnetron mechanism is the core component of the magnetron mechanism circuit breaker. The magnetron mechanism consists of two symmetrical magnet housings, which are attracted when powered on. After attraction, a large ferromagnetic attraction is generated due to the residual holding force. Improving the residual magnetism of the magnet housing material, controlling the coercive force to an appropriate size, and keeping the cost at a low level at the same time are of great significance to the long-term development of the magnetron mechanism circuit breaker.

[0003] However, the existing magnetic shells have the problems of high cost and low holding force, and the raw materials are difficult to obtain. The manufacturing method uses powder metallurgy technology, which is complicated to manufacture and expensive.

[0004] Therefore, there is an urgent need for a magnetic shell material and preparation method for a magnetron mechanism with low cost, high holding force and simple manufacturing method. Summary of the invention

[0005] In order to solve the deficiencies in the prior art, the present invention provides a low-cost, high-holding force, moderate coercive force magnetomechanical shell material and a preparation method thereof. The magnetomechanical shell raw material is based on pure iron, and elements such as C, Cr, and Ni are added to improve the alloy coercive force and the saturation magnetic induction intensity. Then, through heat treatment, better magnetomechanical performance is obtained, the material has large holding force and moderate coercive force, and can be widely used in the magnetomechanical operating mechanism of circuit breakers.

[0006] The present invention adopts the following technical solution.

[0007] The first aspect of the present invention discloses a magnetic shell material of a magnetron mechanism, comprising the following chemical composition elements in mass percentage: carbon C: 0.5-0.55%; chromium Cr: 6.0-8.0%; nickel Ni: 0.20-0.25%; silicon Si: 0.60-0.80%; phosphorus P: ≤0.035%; manganese Mn: ≤0.1%; and the rest is Fe.

[0008] The second aspect of the present invention discloses a method for preparing a magnetic shell of a magnetron mechanism, based on the magnetic shell material of the magnetron mechanism, comprising the following steps:

[0009] Step 1, weigh the raw materials, weigh the raw materials according to the following mass percentages, carbon C: 0.5-0.55%; chromium Cr: 6.0-8.0%%; nickel Ni: 0.20-0.25%; silicon Si: 0.60-0.80%; phosphorus P: ≤0.035%; manganese Mn: ≤0.1%; the rest is Fe;

[0010] Step 2: After mixing the raw materials, forging the blank to obtain a steel ingot;

[0011] Step 3, machining the steel ingot into the required shape of the magnetic shell according to the design size, and obtaining a preliminary formed magnetic shell;

[0012] Step 4: heat-treating the initially formed magnetic shell to obtain a magnetic shell of a magnetron mechanism.

[0013] Preferably, step 2 specifically includes:

[0014] Step 2.1, mixing all the weighed raw materials, completely melting them and then casting them into steel ingots;

[0015] Step 2.2, heat the steel ingot to the set temperature, put the heated steel ingot into the forging die, forge the blank, and cool it at room temperature after forming.

[0016] Preferably, in step 2.2, the set temperature is 850°C, and the heating rate is less than or equal to 50°C / min.

[0017] Preferably, in step 2.2, the blank is forged by placing the steel ingot into a forging die and repeatedly forging it.

[0018] Preferably, step 4 specifically includes:

[0019] Step 4.1, high temperature quenching the preliminarily formed magnetic shell at a set temperature;

[0020] Step 4.2: subjecting the quenched preliminary formed magnetic shell to vacuum high temperature tempering heat treatment to obtain the magnetic shell of the magnetron mechanism.

[0021] Preferably, the set quenching temperature is 960±20°C.

[0022] Preferably, the tempering temperature is 400±20°C.

[0023] Preferably, the quenching time is 2 to 3 hours, and the tempering time is 4 to 5 hours.

[0024] Preferably, the magnetic properties of the magnetic shell of the magnetron mechanism are: at room temperature, B 2000 1.20T~1.30T, B 5000 1.60T~1.7T, Br 5000 1.3T~1.4T, coercive force Hc 5000 It is 1200~1300A / m.

[0025] Compared with the prior art, the beneficial effects of the present invention include at least:

[0026] The magnetic shell material of the present invention is a low alloy carbon steel system, the alloy cost is low, and after heat treatment, it has a higher Curie temperature and higher remanence. The method increases the holding force of the magnetic shell and controls the coercive force to a suitable size, so that when the magnetic shell is used as a circuit breaker operating mechanism, it has both high holding force (greater than 3600N) and strong ability to resist external electromagnetic interference, and can be widely promoted in the field of power distribution switch equipment technology;

[0027] The forged magnetic shell of the present invention contains a supersaturated martensite structure after high-temperature quenching. After vacuum tempering, dispersed carbides are precipitated on the martensite matrix, the saturated magnetic induction intensity of the body is improved, the remanent magnetism Br is improved, and the coercive force of the alloy is improved. After aging heat treatment, the martensite structure is more stable, the grain boundary structure and intracrystalline structure of the alloy are improved, and the strength, hardness and corrosion resistance are improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is the appearance diagram of the upper and lower magnetic shells;

[0029] In the figure: 1, upper magnetic shell; 2, lower magnetic shell. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical scheme and advantages of the present invention clearer, the technical scheme of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. The embodiments described in this application are only embodiments of a part of the present invention, rather than all embodiments. Based on the spirit of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the protection scope of the present invention.

[0031] Embodiment 1 of the present invention provides a magnetic shell material for a magnetron mechanism, wherein the main chemical composition element ratios (%) of the material are: carbon C: 0.5-0.55; chromium Cr: 6.0-8.0%; nickel Ni: 0.20-0.25; silicon Si: 0.60-0.80; phosphorus P: ≤0.035; manganese Mn: ≤0.1; and the rest is Fe. The functions of the alloy elements of the magnetic shell and the alloy design basis are as follows:

[0032] C: 0.5-0.55%, forms alloy carbides with Cr element, which can improve coercive force and remanence; Cr: 6.00-8.00%, forms alloy carbides with C element, which can improve coercive force, saturation magnetization and remanence; Ni: 0.20-0.25%, promotes magnetic properties and increases saturation magnetization; Fe is the matrix of the magnetic shell material of the magnetron mechanism; Silicon Si: 0.60-0.80%; Manganese Mn: ≤0.1%; Phosphorus P is an impurity element, the lower its content, the better.

[0033] The magnetic shell raw material of the present invention is based on pure iron, and the above elements are added to improve the alloy coercive force and saturation magnetic induction intensity.

[0034] Embodiment 2 of the present invention provides a method for preparing the magnetic shell of the low-cost magnetron mechanism, the method comprising the following steps:

[0035] Step 1: Prepare raw materials;

[0036] The raw materials are weighed according to the following mass percentages: carbon C: 0.5-0.55; chromium Cr: 6.0-8.0%; nickel Ni: 0.20-0.25; silicon Si: 0.60-0.80; phosphorus P: ≤0.035; manganese Mn: ≤0.1; and the rest is Fe.

[0037] Step 2, blank forging;

[0038] Step 2 specifically includes:

[0039] Step 2.1, mixing all the weighed raw materials, completely melting them and then casting them into steel ingots;

[0040] Step 2.2, heating the steel ingot to a set temperature, placing the heated steel ingot into a forging die, forging the blank, and cooling at room temperature after forming;

[0041] In a preferred but non-limiting embodiment of the present invention, the set temperature is 850°C, and the heating rate is less than or equal to 50°C / min;

[0042] Further preferably, the blank forging is to place the steel ingot into a forging die and forge it repeatedly to make the material dense and uniform in density.

[0043] It is worth noting that there is currently no requirement for the forging ratio. The processing technology has a forging ratio of approximately 2. Before forging, the steel ingot will have uneven density during molding. After forging, the sparsely dense areas will be closer to the density of other areas.

[0044] Step 3, machining the cooled steel ingot into the desired shape of the magnetic shell according to the design size, and obtaining a preliminary formed magnetic shell;

[0045] Step 4: heat-treating the initially formed magnetic shell to obtain a magnetic shell of a magnetron mechanism.

[0046] Step 4 specifically includes:

[0047] Step 4.1, high temperature quenching the preliminarily formed magnetic shell, the quenching temperature is 960±20℃, and maintained for 2 to 3 hours;

[0048] Step 4.2: subject the initially formed magnetic shell to vacuum high temperature tempering heat treatment at a tempering temperature of 400±20°C for 4 to 5 hours.

[0049] The magnetic shell contains a supersaturated martensite structure after high-temperature quenching. After vacuum tempering, dispersed carbides are precipitated on the martensite matrix, and the saturated magnetic induction intensity of the body is increased, and the remanence Br is increased.

[0050] Magnetic properties of the low-cost magnetron magnetic shell prepared by the above process: Magnetic induction intensity B at room temperature when the magnetic field intensity is 200A / m 2000 The magnetic induction intensity B is 1.20T~1.30T at room temperature and the magnetic field intensity is 500A / m 5000 The magnetic field strength of this material is 1.60T~1.7T. When the magnetic field strength is 500A / m, the material is infinitely close to the saturation magnetic induction strength Bs. When the magnetic field strength increases from 4000A / m to 5000A / m, the magnetic induction strength changes very little. 5000 1.3T~1.4T, coercive force Hc 5000 1200~1300A / m. Figure 1 As shown, the magnetomechanism composed of two symmetrical upper magnetic shells 1 and lower magnetic shells 2 is electrically connected to each other. After being connected, due to the residual holding force, the ferromagnetic attraction force is greater than 3600N.

[0051] The magnetic shell raw material of the present invention is based on pure iron, and elements such as C, Cr, and Ni are added to improve the alloy coercive force and saturation magnetic induction intensity. After heat treatment, better magnetic control performance is obtained, and the material has greater holding force and moderate coercive force, which can increase the holding force by more than 20% and reduce the cost by 30%. The material can be widely used in the magnetic control operating mechanism of circuit breakers.

[0052] Comparative Example 1

[0053] When the tempering temperature is changed to 350°C, the other mass percentages remain unchanged and the holding force is 2800N.

[0054] Comparative Example 2

[0055] Keep the tempering temperature unchanged, when the percentage of raw materials is: carbon C: 0.42 ~ 0.50; chromium Cr: ≤ 0.25;

[0056] Manganese Mn: 0.50~0.80; Nickel Ni: ≤0.25; Phosphorus P: ≤0.035; Sulfur S: ≤0.035; Silicon Si: 0.17~0.37, the rest is iron Fe, and its holding force is 2600N.

[0057] Comparative Example 3

[0058] Keep the tempering temperature unchanged, when the raw material percentage is: carbon C: ≤0.025%; silicon Si: ≤0.20%;

[0059] Manganese Mn: ≤0.30%; Phosphorus P: ≤0.020%; Sulfur S: ≤0.020%; Aluminum Al: 0.15~0.50%; Chromium Cr: ≤0.10%; Nickel Ni: ≤0.20%; Copper Cu: ≤0.20%; The rest is iron Fe, and its holding force is 2300N.

[0060] It can be seen that the comparative examples all failed to reach the holding force of 3600N that could be achieved by the percentage of raw materials and the manufacturing method used in the present invention.

[0061] Compared with the prior art, the beneficial effects of the present invention include at least:

[0062] The magnetic shell material of the present invention is a low alloy carbon steel system, the alloy cost is low, and after heat treatment, it has a higher Curie temperature and higher remanence. The method increases the holding force of the magnetic shell and controls the coercive force to a suitable size, so that when the magnetic shell is used as a circuit breaker operating mechanism, it has both high holding force (greater than 3600N) and strong ability to resist external electromagnetic interference, and can be widely promoted in the field of power distribution switch equipment technology;

[0063] The forged magnetic shell of the present invention contains a supersaturated martensite structure after high-temperature quenching. After vacuum tempering, dispersed carbides are precipitated on the martensite matrix, the saturated magnetic induction intensity of the body is improved, the residual magnetism Br is improved, and the coercive force of the alloy is improved. After aging heat treatment, the martensite structure is more stable, the grain boundary structure and intracrystalline structure of the alloy are improved, and the strength, hardness and corrosion resistance are improved.

[0064] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents, and any modifications or equivalent replacements that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A magnetic shell material for a magnetron mechanism, characterized in that: The chemical composition elements include the following mass percentages: carbon C: 0.5-0.55%; chromium Cr: 6.0-8.0%%; Nickel Ni: 0.20~0.25%; Silicon Si: 0.60~0.80%; Phosphorus P: ≤0.035%; Manganese Mn: ≤0.1%; The rest is Fe.

2. A method for preparing a magnetic shell of a magnetron mechanism, used for preparing a magnetic shell material of a magnetron mechanism according to claim 1, characterized in that: The following steps are involved: Step 1, weigh the raw materials, weigh the raw materials according to the following mass percentages, carbon C: 0.5-0.55%; chromium Cr: 6.0-8.0%%; Nickel Ni: 0.20~0.25%; Silicon Si: 0.60~0.80%; Phosphorus P: ≤0.035%; Manganese Mn: ≤0.1%; The rest is Fe; Step 2: After mixing the raw materials, forging the blank to obtain a steel ingot; Step 3, machining the steel ingot into the required shape of the magnetic shell according to the design size, and obtaining a preliminary formed magnetic shell; Step 4: heat-treating the initially formed magnetic shell to obtain a magnetic shell of a magnetron mechanism.

3. The method for preparing a magnetic shell of a magnetron mechanism according to claim 2, characterized in that: Step 2 specifically includes: Step 2.1, mixing all the weighed raw materials, completely melting them and then casting them into steel ingots; Step 2.2, heat the steel ingot to the set temperature, put the heated steel ingot into the forging die, forge the blank, and cool it at room temperature after forming.

4. The method for preparing a magnetic shell of a magnetron mechanism according to claim 3, characterized in that: In step 2.2, the set temperature is 850°C, and the heating rate is less than or equal to 50°C / min.

5. The method for preparing a magnetic shell of a magnetron mechanism according to claim 3, characterized in that: In step 2.2, the blank is forged by placing the steel ingot into a forging die and repeatedly forging it.

6. The method for preparing a magnetic shell of a magnetron mechanism according to claim 2, characterized in that: Step 4 specifically includes: Step 4.1, high temperature quenching the preliminarily formed magnetic shell at a set temperature; Step 4.2: subjecting the quenched preliminary formed magnetic shell to vacuum high temperature tempering heat treatment to obtain the magnetic shell of the magnetron mechanism.

7. The method for preparing a magnetic shell of a magnetron mechanism according to claim 6, characterized in that: The set quenching temperature is 960±20°C.

8. The method for preparing a magnetic shell of a magnetron mechanism according to claim 6, characterized in that: The tempering temperature is 400±20°C.

9. The method for preparing a magnetic shell of a magnetron mechanism according to claim 6, characterized in that: The quenching time is 2 to 3 hours, and the tempering time is 4 to 5 hours.

10. The method for preparing a magnetic shell of a magnetron mechanism according to claim 2, characterized in that: Magnetic properties of the magnetic shell of the magnetron mechanism: at room temperature, B 2000 1.20T~1.30T, B 5000 1.60T~1.7T, Br 5000 1.3T~1.4T, coercive force Hc 5000 It is 1200~1300A / m.

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