Segmented stepped reciprocating variable-temperature heat treatment method for metal or alloy material

Abstract

The invention relates to a metal or alloy material segmented stepped reciprocating variable-temperature heat treatment method, which is divided into a heating stage and a cooling stage, the heating stage comprises more than three heating processes with different temperatures, the temperature is increased to the highest temperature in a temperature gradient manner, and one cooling process is arranged between the two heating processes. A cooling stage is started after the highest-temperature heat preservation treatment, the cooling stage comprises more than three different-temperature cooling processes, the temperature gradient is reduced to the room temperature, and one heating process exists between the two cooling processes. Compared with a traditional heat treatment method, the segmented stepped reciprocating variable-temperature heat treatment method has the advantages that more heat treatment process parameters can be adopted, the control types of the process parameters are more diversified, the force for adjusting the microstructure of the metal and alloy material is larger, the microstructure adjustment is more uniform and consistent, and the refinement degree is higher; and a new technical thought is provided for the heat treatment of the alloy material.

Description

Technical Field

[0001] The invention belongs to the technical field of alloy or nonferrous metal processing, and in particular relates to a segmented step-by-step reciprocating temperature-changing heat treatment method for metal or alloy materials. Background Art

[0002] Heat treatment is a process of heating, keeping warm, and cooling materials to control their material properties by changing the surface or internal structure of the material.

[0003] Heat treatment of metals and alloys is an important process in mechanical and material manufacturing. It generally does not change the shape and overall chemical composition of the workpiece, but changes the internal microstructure of the workpiece material or the chemical composition of the workpiece surface to improve the physical and chemical properties of the workpiece. Since alloys have multiple elemental components, the heat treatment process of alloy materials is more complicated than that of single metals. After heat treatment, the alloy will form a more uniform organizational structure, so that the alloy material exhibits specific or better physical and chemical properties.

[0004] There are many heat treatment methods for metals and alloys, and each heat treatment method involves the control of heat treatment process parameters. At present, the step heat treatment method is one of the commonly used heat treatment methods, which mainly includes one-way step-type heating heat treatment and one-way step-type cooling heat treatment. However, the current heat treatment methods for metal or alloy materials have certain limitations. First, the number and types of heat treatment process parameters are limited. Second, the ability to adjust the microscopic particle structure of metal and alloy materials is relatively extensive. Ultimately, the improvement of the physical and chemical properties of the material after heat treatment, such as mechanical properties, electromagnetic properties, and electrochemical properties, is limited. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a segmented step-by-step reciprocating temperature-changing heat treatment method for metal or alloy materials in view of the deficiencies in the prior art. The method includes a heating stage and a cooling stage. Both the heating stage and the cooling stage include three processes of heating, heat preservation and cooling. A greater number of heat treatment process parameters can be adopted, and the types of process parameter control are more diverse. The metal and alloy materials are repeatedly treated through the three processes of heating, heat preservation and cooling in the heating stage and the cooling stage. The microstructure of the material is more uniform, consistent and fine, and the physical and chemical properties of the material, such as mechanical properties, electrochemistry, and electromagnetics, are better.

[0006] The present invention provides a segmented step-by-step reciprocating variable temperature heat treatment method for metal or alloy materials, which is divided into a heating stage and a cooling stage. The heating stage includes more than three heating processes at different temperatures, the temperature gradient rises to the highest temperature, and there is a cooling process between two heating processes. After the highest temperature insulation treatment, the cooling stage begins. The cooling stage includes more than three cooling processes at different temperatures, the temperature gradient drops to room temperature, and there is a heating process between two cooling processes.

[0007] According to the above scheme, the specific steps of the metal or alloy material step-by-step reciprocating temperature change heat treatment method are as follows:

[0008] S1, heating stage: the metal or alloy material is placed in a heat treatment furnace and heated in an inert atmosphere. The heating program is as follows: the temperature is raised to the first insulation temperature T1 at a heating rate of a1, and the insulation time is t1, and then the temperature is lowered to the second insulation temperature T2 at a cooling rate of a2, and the insulation time is t2, and then the temperature is raised to the third insulation temperature T3 at a heating rate of a3, and the insulation time is t3, and then the temperature is lowered, the insulation, the heating, and the insulation steps are sequentially performed until the nth heating reaches the highest temperature Tn (Tn = T max ), the holding time is tn;

[0009] S2, cooling stage, the cooling procedure is as follows: cool down to the first insulation temperature R1 at the cooling rate of b1, keep it at this temperature for d1, then heat up to the second insulation temperature R2 at the heating rate of b2, keep it at this temperature for d2, then cool down to the third insulation temperature R3 at the cooling rate of b3, keep it at this temperature for d3, then follow the heating, keeping, cooling, keeping steps in sequence until the mth cooling down to the room temperature Rm (Rm = T room ), the holding time is dm (dm=0).

[0010] According to the above scheme, in step S1, n≥3, and n is an odd number.

[0011] According to the above scheme, in step S1, the heating rate is 1-10°C / min, and the cooling rate is 0.1-1°C / min.

[0012] According to the above scheme, in step S1, Tn>Tn-2>…>T1, T2p<T2p-1 and T2n<T2p+1, and p is an integer between 1 and (n-1) / 2 (including the endpoints).

[0013] According to the above scheme, the insulation time in step S1 is 10 to 60 minutes.

[0014] According to the above scheme, the T max It is the heating temperature specified in JB / T 7712-1995 standard.

[0015] According to the above scheme, in step S2, m≥3, and m is an odd number.

[0016] According to the above scheme, in step S2, the heating rate is 1-10°C / min, and the cooling rate is 0.1-3°C / min.

[0017] According to the above scheme, in step S2, Rm<Rm-2<…<R1<Tn, R2q>R2q-1 and R2q>R2q+1, and q is an integer between 1 and (m-1) / 2 (including the endpoints).

[0018] According to the above scheme, the insulation time in step S2 is 0 to 60 minutes.

[0019] The present invention also includes metal or alloy materials obtained by the above-mentioned segmented step-by-step reciprocating variable temperature heat treatment method. The segmented step-by-step reciprocating variable temperature heat treatment process used by a specific alloy material can explore specific process conditions according to actual needs, and can obtain alloy materials with better hardness or elastic modulus, more finely control the magnetic permeability and electrical conductivity of magnetic alloy materials, or obtain alloy materials with better corrosion resistance.

[0020] The beneficial effects of the present invention are as follows: 1. Compared with the traditional heat treatment method, the segmented step-by-step reciprocating temperature-changing heat treatment method of the present invention can adopt more heat treatment process parameters, more diverse process parameter control types, greater power to adjust the microstructure of metal and alloy materials, more uniform and consistent microstructure adjustment, higher degree of refinement, and provides a new technical idea for the heat treatment of alloy materials. 2. The alloy material obtained by the heat treatment method of the present invention has a special microstructure and physical and chemical properties, can obtain the material potential of specific performance, and has better physical and chemical properties such as mechanical properties, electrochemistry, and electromagnetics, which broadens the application range of alloy materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of a stepwise reciprocating variable temperature heat treatment process according to Example 1 of the present invention;

[0022] Figure 2 This is the XRD pattern of the iron-based alloy sample used in Example 1 before heat treatment;

[0023] Figure 3 This is the XRD diagram of the iron-based alloy sample after heat treatment in Example 1. DETAILED DESCRIPTION

[0024] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail using embodiments and in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0025] Example 1

[0026] A stepwise reciprocating temperature-changing heat treatment method for an iron-based alloy material, the specific steps are as follows:

[0027] 1. Heating process: Place the iron-based alloy (Fe90Cu0.5Si5.5B4 alloy) in a tubular furnace, use a vacuum pump to extract the air in the tubular furnace, close the vacuum pump and the corresponding valves, introduce high-purity argon as a heat treatment protective gas, make the air pressure in the quartz tube consistent with the atmospheric pressure, then close the gas valve, repeat the gas washing 3 times, so that the iron-based alloy is in an argon atmosphere, set the air pressure in the tubular furnace to <0.1MPa, and the heating program is as follows:

[0028] S1, heating up to the first annealing temperature T1 at a heating rate of 1°C / min, T1 = 150°C, and keeping temperature t1, t1 = 30min;

[0029] S2, cooling down to the second insulation temperature T2 at a cooling rate of 0.5°C / min, T2 = 120°C, insulation t2, t2 = 30min;

[0030] S3, heating up to the third stage insulation temperature T3 at a heating rate of 5°C / min, T3 = 200°C, insulation time t3, t3 = 30min;

[0031] S4, cooling down to the fourth stage insulation temperature T4 at a cooling rate of 0.3°C / min, T4 = 100°C, insulation time t4, t4 = 30min;

[0032] S5, heating up to the fifth stage insulation temperature T5 at a heating rate of 5°C / min, T5 = 500°C, insulation for t5, t5 = 30min;

[0033] S6, cooling at a cooling rate of 1°C / min to the sixth holding temperature T6, T6 = 300°C, holding for t6, t6 = 30min;

[0034] S7, heating up to the seventh holding temperature T7 at a heating rate of 5°C / min, T7 = 600°C, holding for t7, t7 = 30min;

[0035] 2. Cooling process: adopt step-by-step reciprocating cooling process. After the heat treatment at the highest temperature of 600℃, the temperature is cooled by step-by-step reciprocating cooling. The specific cooling procedure is as follows:

[0036] J1, cool down to the first insulation temperature T1, T1 = 400°C, at a cooling rate of 1.5°C / min, and keep warm for t1, t1 = 20min;

[0037] J2, heating up to the second insulation temperature T2 at a heating rate of 3°C / min, T2 = 450°C, insulation t2, t2 = 20min;

[0038] J3, cooling down with the furnace (cooling rate is about 0.3℃ / min) to the third insulation temperature T3, T3 = 200℃, insulation t3, t3 = 20min;

[0039] J4, heating up to the fourth stage insulation temperature T4 at a heating rate of 3.5°C / min, T4 = 300°C, insulation for t2, t2 = 20min;

[0040] J5, cool down to the fifth insulation temperature T5 at a cooling rate of 1.5°C / min, T5 = 100°C, insulation temperature t5, t5 = 20min;

[0041] J6, heating up to the sixth holding temperature T6 at a heating rate of 3.5°C / min, T6 = 150°C, holding temperature t6, t6 = 20min;

[0042] J7. Cool naturally to room temperature in the furnace.

[0043] like Figure 1 Shown is a schematic diagram of the segmented step-by-step reciprocating variable temperature heat treatment process of this embodiment.

[0044] Figure 2 This is the XRD diagram of the iron-based alloy sample used in this embodiment before heat treatment. It can be seen that its microstructure is amorphous. Figure 3 : is the XRD diagram of the iron-based alloy sample after heat treatment. By comparison, it can be seen that the heat treatment method of this embodiment changes the microstructure of the iron-based alloy and the grains inside the material grow.

[0045] The saturation magnetic induction intensity of the iron-based alloy material in this embodiment reaches 1.7T after heat treatment, and it has high magnetic permeability, low coercive force and low hysteresis loss, which is conducive to the efficient transmission of magnetic field energy and can be applied to medium and low frequency electrical equipment.

Claims

1. A metal or alloy material segmented step-by-step reciprocating temperature-changing heat treatment method, characterized in that: It is divided into a heating stage and a cooling stage. The heating stage includes more than three heating processes at different temperatures. The temperature gradient rises to the highest temperature, and there is a cooling process between two heating processes. After the highest temperature insulation treatment, it enters the cooling stage. The cooling stage includes more than three cooling processes at different temperatures. The temperature gradient drops to room temperature, and there is a heating process between two cooling processes.

2. The metal or alloy material segmented stepwise reciprocating temperature-changing heat treatment method according to claim 1, characterized in that: The specific steps of the metal or alloy material step-by-step reciprocating temperature-changing heat treatment method are as follows: S1, heating stage: the metal or alloy material is placed in a heat treatment furnace and heated in an inert atmosphere. The heating program is as follows: the temperature is raised to the first insulation temperature T1 at a heating rate of a1, and the insulation time is t1, and then the temperature is lowered to the second insulation temperature T2 at a cooling rate of a2, and the insulation time is t2, and then the temperature is raised to the third insulation temperature T3 at a heating rate of a3, and the insulation time is t3, and then the temperature is lowered, the insulation, the heating, and the insulation steps are sequentially performed until the nth heating reaches the highest temperature Tn, Tn = T max , the holding time is tn; S2, cooling stage, the cooling procedure is as follows: cool down to the first insulation temperature R1 at the cooling rate of b1, the insulation time is d1, then heat up to the second insulation temperature R2 at the heating rate of b2, the insulation time is d2, then cool down to the third insulation temperature R3 at the cooling rate of b3, insulation time d3, then follow the heating, insulation, cooling, insulation steps in sequence until the mth cooling to room temperature Rm, Rm = T room , the insulation time is dm, dm=0.

3. The metal or alloy material segmented stepwise reciprocating temperature-changing heat treatment method according to claim 2, characterized in that: In step S1, n≥3, and n is an odd number.

4. The metal or alloy material segmented stepwise reciprocating temperature-changing heat treatment method according to claim 2, characterized in that: In step S1, the heating rate is 1-10°C / min, and the cooling rate is 0.1-1°C / min.

5. The metal or alloy material segmented stepwise reciprocating temperature-changing heat treatment method according to claim 2, characterized in that: In step S1, Tn>Tn-2>…>T1, T2p<T2p-1 and T2n<T2p+1, and p is an integer between 1 and (n-1) / 2.

6. The metal or alloy material segmented stepwise reciprocating temperature-changing heat treatment method according to claim 2, characterized in that: The holding time in step S1 is 10 to 60 minutes; max It is the heating temperature specified in JB / T 7712-1995 standard.

7. The metal or alloy material segmented step-by-step reciprocating temperature-changing heat treatment method according to claim 2, characterized in that: In step S2, m≥3, and m is an odd number.

8. The metal or alloy material segmented stepwise reciprocating temperature-changing heat treatment method according to claim 2, characterized in that: In step S2, the heating rate is 1-10°C / min, and the cooling rate is 0.1-3°C / min.

9. The metal or alloy material segmented stepwise reciprocating temperature-changing heat treatment method according to claim 2, characterized in that: In step S2, Rm<Rm-2<…<R1<Tn, R2q>R2q-1 and R2q>R2q+1, q is an integer between 1 and (m-1) / 2; and the insulation time in step S2 is 0 to 60 minutes.

10. The metal or alloy material obtained by the metal or alloy material segmented stepwise reciprocating temperature change heat treatment method according to any one of claims 1 to 9.

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