阅读说明：本技术 一种整圆环磁轭锻件的锻后热处理工艺 (Post-forging heat treatment process for full-circle magnetic yoke forging ) 是由 李潜 刘少斌 温玉磊 李福强 张帆 路荣远 于 2021-07-21 设计创作，主要内容包括：本发明提供了一种整圆环磁轭锻件的锻后热处理工艺,具体涉及磁轭配件制备方法领域,该工艺能够解决磁轭锻件不符合产品要求的问题。该热处理工艺包括如下步骤：将锻造后的整圆环磁轭锻件装炉,冷却至660±15℃,保温后,冷却至300±30℃,保温后,升温至660±15℃,保温后,升温至890～920℃,保温后,冷却至690±15℃,保温后,冷却至660±15℃,保温后,冷却至300℃后,将整圆环磁轭锻件取出在空气中冷却至常温。本发明整圆环磁轭锻件的锻后热处理工艺能够有效改善整圆环磁轭锻件的金相组织和晶粒度,确保生产出的整圆环磁轭锻件符合产品要求。(The invention provides a post-forging heat treatment process for a full-circle magnetic yoke forging, and particularly relates to the field of a preparation method of a magnetic yoke accessory. The heat treatment process comprises the following steps: and charging the forged whole-circular-ring magnetic yoke forging into a furnace, cooling to 660 +/-15 ℃, preserving heat, cooling to 300 +/-30 ℃, preserving heat, heating to 660 +/-15 ℃, preserving heat, heating to 890-920 ℃, preserving heat, cooling to 690 +/-15 ℃, preserving heat, cooling to 660 +/-15 ℃, preserving heat, cooling to 300 ℃, taking out the whole-circular-ring magnetic yoke forging, and cooling to normal temperature in the air. The after-forging heat treatment process of the full-circle magnetic yoke forging can effectively improve the metallographic structure and the grain size of the full-circle magnetic yoke forging and ensure that the produced full-circle magnetic yoke forging meets the product requirements.)

1. A post-forging heat treatment process of a full-circle magnetic yoke forging is characterized by comprising the following steps: which comprises the following steps:

(1) charging the forged whole-circular-ring magnetic yoke forging into a furnace, cooling to 660 +/-15 ℃, and carrying out primary heat preservation treatment;

(2) cooling to 300 +/-30 ℃, and carrying out secondary heat preservation treatment;

(3) heating to 660 +/-15 ℃, and carrying out heat preservation treatment for the third time;

(4) heating to 890-920 ℃, and carrying out fourth heat preservation treatment;

(5) cooling to 690 +/-15 ℃, and carrying out fifth heat preservation treatment;

(6) cooling to 660 +/-15 ℃, and carrying out sixth heat preservation treatment;

(7) and cooling to 300 ℃, taking out the whole circular ring magnetic yoke forging and cooling to normal temperature in the air.

2. The post-forging heat treatment process of the full-circle magnetic yoke forging as claimed in claim 1, characterized in that: in the step (1), the cooling rate is less than or equal to 30 ℃/h.

3. The post-forging heat treatment process of the full-circle magnetic yoke forging as claimed in claim 1, characterized in that: in the step (2), the cooling rate is less than or equal to 30 ℃/h.

4. The post-forging heat treatment process of the full-circle magnetic yoke forging as claimed in claim 1, characterized in that: in the step (3), the temperature rise rate is less than or equal to 30 ℃/h.

5. The post-forging heat treatment process of the full-circle magnetic yoke forging as claimed in claim 1, characterized in that: in the step (4), the temperature rise rate is less than or equal to 100 ℃/h.

6. The post-forging heat treatment process of the full-circle magnetic yoke forging as claimed in claim 1, characterized in that: in the step (5), the cooling rate is less than or equal to 30 ℃/h.

7. The post-forging heat treatment process of the full-circle magnetic yoke forging as claimed in claim 1, characterized in that: in the step (6), the cooling rate is less than or equal to 10 ℃/h.

8. The post-forging heat treatment process of the full-circle magnetic yoke forging as claimed in claim 1, characterized in that: in the step (7), the cooling rate is less than or equal to 30 ℃/h.

9. The post-forging heat treatment process of the full-circle magnetic yoke forging as claimed in claim 1, characterized in that: in the step (5), the step (6) and the step (7), the cooling is furnace sealing cooling.

Technical Field

The invention relates to the field of a preparation method of a magnetic yoke accessory, in particular to a post-forging heat treatment process of a full-circle magnetic yoke forging.

Background

The magnet yoke is a key part of the generator motor, plays an important role in the operation process of the generator motor set, and the stability of the magnet yoke structure directly influences the safe and reliable operation of the set. The magnetic yoke is also an important component of a magnetic circuit of the generator motor, and the magnetic yoke is subjected to the comprehensive action of centrifugal force, electromagnetic force and torque in the operation process, so that the generator motor has high requirements on various properties of the magnetic yoke. Particularly, the pumped storage generator motor has severe requirements on the magnet yoke due to frequent start and stop, positive and negative rotation, high rotating speed and severe working condition operation.

The existing magnet yoke is mostly formed by laminating and pressing high-strength annular thick steel plates, the annular thick steel plates are integrated by laminating and welding, the manufacturing process is complex, the interchangeability is poor, the technical requirement is high, the integral rigidity is limited, the plate utilization rate is low, the manufacturing period is long, gaps exist among the steel plates, and the problems of deformation, malocclusion and the like easily occur in the production, transportation and installation processes. The invention aims to solve the problems, the whole circular ring magnetic yoke forging piece is invented, the heat treatment technology after forging of the whole circular ring magnetic yoke forging piece is not mature, and the quality of the whole circular ring magnetic yoke forging piece cannot be ensured.

Disclosure of Invention

The invention aims to provide a post-forging heat treatment process of a full-circle magnetic yoke forging, which can ensure that the quality of the full-circle magnetic yoke forging is qualified.

In order to meet the technical purpose and the related technical purpose, the invention provides a post-forging heat treatment process of a full-circle magnetic yoke forging, which comprises the following steps:

the forging process requires a final forging temperature of greater than or equal to 800 ℃.

1. Charging the forged whole-circular-ring magnetic yoke forging into a furnace, cooling to 660 +/-15 ℃, carrying out first heat preservation treatment, wherein the calculation formula of the heat preservation time is 1.5-2.5 h/100mm, the time needing heat preservation is calculated according to the specific size of the forging, and if the size of the forging is 300mm, the heat preservation time is 4.5-7.5 hours;

2. cooling to 300 +/-30 ℃, and carrying out secondary heat preservation treatment, wherein the calculation formula of the heat preservation time is 2-3 h/100 mm;

3. heating to 660 +/-15 ℃, and carrying out third heat preservation treatment, wherein the calculation formula of the heat preservation time is 1-1.5 h/100 mm;

4. heating to 890-920 ℃, and carrying out fourth heat preservation treatment, wherein the calculation formula of the heat preservation time is 2.5-3.5 h/100 mm;

5. cooling to 690 +/-15 ℃, and carrying out fifth heat preservation treatment, wherein the calculation formula of the heat preservation time is 2.5-3.5 h/100 mm;

6. cooling to 660 +/-15 ℃, and carrying out sixth heat preservation treatment, wherein the calculation formula of the heat preservation time is 2.5-3.5 h/100 mm;

7. and cooling to 300 ℃, taking out the whole circular ring magnetic yoke forging and cooling to normal temperature in the air.

In one example of the post-forging heat treatment process of the full-circle magnetic yoke forging of the present invention, in step 1, the cooling rate is less than or equal to 30 ℃/h.

In an example of the post-forging heat treatment process of the full-circle magnetic yoke forging of the present invention, in step 2, the cooling rate is less than or equal to 30 ℃/h.

In one example of the post-forging heat treatment process of the full-circle magnetic yoke forging of the present invention, in step 3, the temperature rise rate is less than or equal to 30 ℃/h.

In an example of the post-forging heat treatment process of the full-circle magnetic yoke forging of the invention, in step 4, the temperature rise rate is less than or equal to 100 ℃/h.

In one example of the post-forging heat treatment process of the full-circle magnetic yoke forging of the present invention, in step 5, the cooling rate is less than or equal to 30 ℃/h.

In an example of the post-forging heat treatment process of the full-circle magnetic yoke forging of the present invention, in step 6, the cooling rate is 10 ℃/h or less.

In an example of the post-forging heat treatment process of the full-circle magnetic yoke forging of the present invention, in step 7, the cooling rate is 30 ℃/h or less.

In an example of the post-forging heat treatment process of the full-circle magnetic yoke forging, in the step 5, the step 6 and the step 7, the cooling is sealing furnace cooling.

The after-forging heat treatment process of the full-circle magnetic yoke forging can effectively improve the metallographic structure and the grain size of the full-circle magnetic yoke forging and ensure that the produced full-circle magnetic yoke forging meets the product requirements.

Drawings

FIG. 1 is a graph of a post-forging heat treatment process for a full-circle yoke forging of the present invention;

FIG. 2 is a microstructure of sample a and sample b of a full ring yoke forging prepared in example 1 of the present invention;

FIG. 3 is a grain size inspection chart of sample a and sample b of a full-circle yoke forging produced in example 1 of the present invention;

FIG. 4 is a CCT curve of a full-circle magnetic yoke forging.

Detailed Description

The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention. It is to be noted that the features in the following embodiments and examples may be combined with each other without conflict. It is also to be understood that the terminology used in the examples is for the purpose of describing particular embodiments only, and is not intended to limit the scope of the present invention. Test methods in which specific conditions are not specified in the following examples are generally carried out under conventional conditions or under conditions recommended by the respective manufacturers.

When numerical ranges are given in the examples, it is understood that both endpoints of each of the numerical ranges and any value therebetween can be selected unless the invention otherwise indicated. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs and the description of the present invention, and any methods, apparatuses, and materials similar or equivalent to those in the embodiments of the present invention may be used to practice the present invention.

The component detection result of the whole circular ring magnetic yoke forging piece is as follows: 0.178% of C, 0.27% of Si, 0.83% of Mn0.006% of P, 0.004% of S, 0.71% of Cr0.29% of Mo0.29% of Ni, 1.53% of V, 0.015% of Cu0.1% of Nb0.015% of Ti, 0.008% of Ceq0.632% of Fe, and the balance of Fe. Wherein Ceq is C + Mn/6+ (Cr + Mo + V)/5+ (Ni + Cu)/15.

Referring to fig. 4, fig. 4 is a CCT curve diagram of a full-circle magnetic yoke forging. The CCT curve is a supercooled austenite continuous cooling transformation curve, reflects the transformation rule of supercooled austenite under the continuous cooling condition, is a basis for analyzing the structure and performance of a transformation product, and is also an important reference material for establishing a heat treatment process.

As can be seen from FIG. 4, the transformation range of the material B (bainite) is wide, while the transformation ranges of the material F (ferrite) and the material P (pearlite) are shifted to the right and narrow, and the effective transformation range is only 30-70 ℃. According to the data, the invention provides a post-forging heat treatment process of the full-circle magnetic yoke forging.

Referring to fig. 1, fig. 1 shows a post-forging heat treatment process for a full-circle magnetic yoke forging according to the present invention.

A post-forging heat treatment process for a full-circle magnetic yoke forging comprises the following steps:

the forging process requires a final forging temperature of greater than or equal to 800 ℃.

1. Charging the forged whole-circular-ring magnetic yoke forging into a furnace, cooling to 660 +/-15 ℃, carrying out first heat preservation treatment, wherein the calculation formula of the heat preservation time is 1.5-2.5 h/100mm, the time needing heat preservation is calculated according to the specific size of the forging, and if the size of the forging is 300mm, the heat preservation time is 4.5-7.5 hours;

2. cooling to 300 +/-30 ℃, and carrying out secondary heat preservation treatment, wherein the calculation formula of the heat preservation time is 2-3 h/100 mm;

3. heating to 660 +/-15 ℃, and carrying out third heat preservation treatment, wherein the calculation formula of the heat preservation time is 1-1.5 h/100 mm;

4. heating to 890-920 ℃, and carrying out fourth heat preservation treatment, wherein the calculation formula of the heat preservation time is 2.5-3.5 h/100 mm;

5. cooling to 690 +/-15 ℃, and carrying out fifth heat preservation treatment, wherein the calculation formula of the heat preservation time is 2.5-3.5 h/100 mm;

6. cooling to 660 +/-15 ℃, and carrying out sixth heat preservation treatment, wherein the calculation formula of the heat preservation time is 2.5-3.5 h/100 mm;

7. and cooling to 300 ℃, taking out the whole circular ring magnetic yoke forging and cooling to normal temperature in the air.

In one example of the post-forging heat treatment process of the full-circle magnetic yoke forging of the present invention, in step 1, the cooling rate is less than or equal to 30 ℃/h.

In an example of the post-forging heat treatment process of the full-circle magnetic yoke forging of the present invention, in step 2, the cooling rate is less than or equal to 30 ℃/h.

In one example of the post-forging heat treatment process of the full-circle magnetic yoke forging of the present invention, in step 3, the temperature rise rate is less than or equal to 30 ℃/h.

In an example of the post-forging heat treatment process of the full-circle magnetic yoke forging of the invention, in step 4, the temperature rise rate is less than or equal to 100 ℃/h.

In one example of the post-forging heat treatment process of the full-circle magnetic yoke forging of the present invention, in step 5, the cooling rate is less than or equal to 30 ℃/h.

In an example of the post-forging heat treatment process of the full-circle magnetic yoke forging of the present invention, in step 6, the cooling rate is 10 ℃/h or less.

In an example of the post-forging heat treatment process of the full-circle magnetic yoke forging of the present invention, in step 7, the cooling rate is 30 ℃/h or less.

In an example of the post-forging heat treatment process of the full-circle magnetic yoke forging, in the step 5, the step 6 and the step 7, the cooling is sealing furnace cooling.

According to the steps, the whole circular ring magnetic yoke forging is subjected to post-forging heat treatment, the structure can be changed to stay for a long time in the change area of the material F and the material P, the occupation ratio of the material F and the material P in the whole circular ring magnetic yoke forging is improved, the occupation ratio of the material B is reduced, and the thick material B is changed into the thin material B. In the later-stage tempering process, the influence of coarse grain size and even mixed crystal on the performance of the whole circular ring magnetic yoke forging piece caused by coarse material B through tissue inheritance can be effectively avoided. Therefore, the metallographic structure and the grain size of the whole circular ring magnetic yoke forging can be improved, the mechanical property of the whole circular ring magnetic yoke forging is improved, and the produced whole circular ring magnetic yoke forging can meet the product requirement.

Example 1

Forging a 300mm full-circle magnetic yoke forging, wherein the final forging temperature is more than or equal to 800 ℃, and carrying out heat treatment after forging according to the following steps:

1. and charging the whole circular ring magnetic yoke forging into a furnace, cooling to 645 ℃ at a cooling speed of 30 ℃/h, and carrying out primary heat preservation treatment for 4.5 hours.

2. Cooling to 270 ℃ at a cooling speed of 30 ℃/h, and carrying out second heat preservation treatment for 6 hours.

3. Heating to 645 ℃ at the heating rate of 30 ℃/h, and carrying out heat preservation treatment for the third time, wherein the heat preservation time is 3 hours.

4. Heating to 890 ℃ at the heating rate of 100 ℃/h, and carrying out heat preservation treatment for the fourth time, wherein the heat preservation time is 7.5 hours.

5. Sealing the furnace at a cooling speed of 30 ℃/h and cooling to 675 ℃, and carrying out fifth heat preservation treatment, wherein the heat preservation time is 7.5 hours.

6. Sealing the furnace at a cooling speed of 10 ℃/h and cooling to 645 ℃, and carrying out the sixth heat preservation treatment, wherein the heat preservation time is 7.5 hours.

7. And cooling to 300 ℃, taking out the whole circular ring magnetic yoke forging, and cooling to normal temperature in air.

Example 2

Forging a 300mm full-circle magnetic yoke forging, wherein the final forging temperature is more than or equal to 800 ℃, and carrying out heat treatment after forging according to the following steps:

1. and (3) charging the whole circular ring magnetic yoke forging into a furnace, cooling to 675 ℃ at a cooling speed of 25 ℃/h, and carrying out primary heat preservation treatment for 7.5 hours.

2. Cooling to 330 ℃ at a cooling speed of 25 ℃/h, and carrying out secondary heat preservation treatment for 9 hours.

3. Heating to 675 ℃ at the heating rate of 25 ℃/h, and carrying out heat preservation treatment for the third time, wherein the heat preservation time is 4.5 hours.

4. Heating to 920 ℃ at the heating rate of 90 ℃/h, and carrying out heat preservation treatment for the fourth time, wherein the heat preservation time is 10.5 hours.

5. Sealing the furnace at the cooling speed of 25 ℃/h and cooling to 705 ℃, and carrying out fifth heat preservation treatment, wherein the heat preservation time is 10.5 hours.

6. And sealing the furnace at the cooling speed of 8 ℃/h and cooling to 675 ℃, and carrying out sixth heat preservation treatment for 10.5 hours.

7. And cooling to 300 ℃, taking out the whole circular ring magnetic yoke forging, and cooling to normal temperature in air.

Example 3

Forging a 300mm full-circle magnetic yoke forging, wherein the final forging temperature is more than or equal to 800 ℃, and carrying out heat treatment after forging according to the following steps:

1. and (3) charging the whole circular ring magnetic yoke forging into a furnace, cooling to 660 ℃ at a cooling speed of 20 ℃/h, and carrying out primary heat preservation treatment for 7 hours.

2. Cooling to 300 ℃ at a cooling speed of 30 ℃/h, and carrying out secondary heat preservation treatment for 8 hours.

3. Heating to 660 ℃ at the heating rate of 30 ℃/h, and carrying out heat preservation treatment for the third time, wherein the heat preservation time is 4 hours.

4. Heating to 900 ℃ at the heating rate of 80 ℃/h, and carrying out heat preservation treatment for the fourth time, wherein the heat preservation time is 10 hours.

5. Sealing the furnace at a cooling speed of 20 ℃/h for cooling to 690 ℃, and carrying out fifth heat preservation treatment for 9 hours.

6. Sealing the furnace at a cooling speed of 5 ℃/h and cooling to 660 ℃, and carrying out sixth heat preservation treatment for 8 hours.

7. And cooling to 300 ℃, taking out the whole circular ring magnetic yoke forging, and cooling to normal temperature in air.

Example 4

Forging a 300mm full-circle magnetic yoke forging, wherein the final forging temperature is more than or equal to 800 ℃, and carrying out heat treatment after forging according to the following steps:

1. and (3) charging the whole circular ring magnetic yoke forging into a furnace, cooling to 675 ℃ at a cooling speed of 30 ℃/h, and carrying out primary heat preservation treatment for 4.5 hours.

2. Cooling to 270 ℃ at a cooling speed of 20 ℃/h, and carrying out secondary heat preservation treatment for 9 hours.

3. Heating to 660 ℃ at the heating rate of 20 ℃/h, and carrying out heat preservation treatment for the third time, wherein the heat preservation time is 3 hours.

4. Heating to 920 ℃ at the heating rate of 100 ℃/h, and carrying out heat preservation treatment for the fourth time, wherein the heat preservation time is 10.5 hours.

5. And sealing the furnace at a cooling speed of 20 ℃/h and cooling to 675 ℃, and carrying out fifth heat preservation treatment, wherein the heat preservation time is 7.5 hours.

6. Sealing the furnace at a cooling speed of 10 ℃/h and cooling to 660 ℃, and carrying out heat preservation treatment for the sixth time, wherein the heat preservation time is 10.5 hours.

7. And cooling to 300 ℃, taking out the whole circular ring magnetic yoke forging, and cooling to normal temperature in air.

The whole-ring magnetic yoke forging pieces prepared in the embodiments 1 to 4 were sampled at 1/2 thicknesses 90mm from the edge of the inner hole, two groups of samples symmetric about the central axis, namely, sample a and sample b, were taken, and the obtained sample a and sample b were prepared into test samples for metallographic structure examination and grain size examination. Next, the test results of the sample of the full-ring yoke forging prepared in example 1 are analyzed.

Referring to fig. 2, fig. 2 is a microstructure of a forged full-circle yoke forging of the present invention, which is subjected to heat treatment after forging, as shown in sample a and sample b. Metallographic microscope is used for carrying out metallographic analysis tests on samples a and B, the magnification times are 100 times, as can be seen from figure 2, the metallographic structure of the sample a is made of a material P, a material F and a fine material B, and the metallographic structure of the sample B is made of a material P, a material F and a fine material B. Therefore, the metallographic structure of the full-circle magnetic yoke forging prepared in embodiment 1 is made of the material P, the material F and the fine material B, and the metallographic structure is favorable for the next quenching and tempering treatment, so that the product requirement can be met.

Referring to fig. 3, fig. 3 is a grain size inspection chart of a sample a and a sample b of the forged full-circle yoke forging of the present invention after heat treatment. The metallographic microscope is used for carrying out grain size inspection on the samples of the sample a and the sample b, the magnification times are both 100 times, and as can be seen from fig. 3, the grain size of the sample a is 5-grade, and the grain size of the sample b is 5-grade, so that the grain size of the full-circle magnetic yoke forging prepared in the embodiment 1 is 5-grade, and the requirement of the product can be met.

The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.