Ionic nitriding process for parking brake ejector rod of railway vehicle
阅读说明：本技术 一种轨道车辆停放制动顶杆的离子氮化工艺 (Ionic nitriding process for parking brake ejector rod of railway vehicle ) 是由 廉婧婧 于 2020-01-02 设计创作，主要内容包括：本发明涉及一种轨道车辆停放制动顶杆的离子氮化工艺,包括制动顶杆以及对制动顶杆进行离子氮化、锻后退火、粗车后调质以及精车前去应力时效处理,制动顶杆一端具有内螺纹孔,另一端具有密封槽,离子氮化工艺步骤如下：在制动顶杆有内螺纹孔的一端套上第一防护套,制动顶杆有密封槽的另一端套上第二防护套,将套有防护套的制动顶杆放入氮化炉中摆放好进行氮化,待氮化炉自然冷却到室温取出；本发明的目的是克服现有技术存在的缺陷,提供一种尽可能控制离子氮化处理给零件尺寸带来变形的影响,达到氮化处理后制动顶杆各尺寸变形量基本均匀一致,没有离散性以及确保在氮化后不再需要进行机加工的一种轨道车辆停放制动顶杆的离子氮化工艺。(The invention relates to an ion nitriding process of a parking brake ejector rod of a railway vehicle, which comprises the following steps of carrying out ion nitriding on the brake ejector rod, annealing after forging, tempering after rough turning and stress relief aging treatment before finish turning on the brake ejector rod, wherein one end of the brake ejector rod is provided with an internal thread hole, and the other end of the brake ejector rod is provided with a sealing groove, and the ion nitriding process comprises the following steps: sleeving a first protective sleeve on one end of the brake ejector rod with the internal thread hole, sleeving a second protective sleeve on the other end of the brake ejector rod with the sealing groove, putting the brake ejector rod sleeved with the protective sleeve into a nitriding furnace, nitriding, and taking out the nitriding furnace after the nitriding furnace is naturally cooled to room temperature; the invention aims to overcome the defects in the prior art, and provides the ion nitriding process for the rail vehicle parking brake ejector rod, which can control the influence of ion nitriding treatment on the deformation of the part size as much as possible, achieve the purposes that the deformation of each size of the brake ejector rod after nitriding treatment is basically uniform and consistent, has no discreteness, and ensures that machining is not needed any more after nitriding.)
1. An ion nitriding process of a parking brake ejector rod of a railway vehicle comprises the steps of carrying out ion nitriding, annealing after forging, tempering after rough turning and stress relief aging treatment before finishing on the brake ejector rod; the hardness of the brake ejector rod (1) is HRC 33-35; the method is characterized in that: one end of the brake ejector rod (1) is provided with an internal thread hole (3), and the other end of the brake ejector rod is provided with a sealing groove (2); one end of the brake ejector rod (1) provided with the internal thread hole (3) is sleeved with a first protective sleeve (4); one end of the brake ejector rod (1) provided with the sealing groove (2) is sleeved with a second protective sleeve (5); the ion nitriding process comprises the following steps:
a. before nitriding treatment, performing blunting treatment on a hole sharp corner on the brake ejector rod (1);
b. a first protective sleeve (4) is sleeved at one end of the brake ejector rod (1) with the internal thread hole (3), and a second protective sleeve (5) is sleeved at the other end of the brake ejector rod (1) with the sealing groove (2);
c. putting the brake ejector rod (1) sleeved with the first protective sleeve (4) and the second protective sleeve (5) into a nitriding furnace;
d. in the ion nitriding temperature rise stage, when the temperature of the brake ejector rod (1) rises to 300 ℃, keeping the temperature for 3 hours, then raising the temperature to 540 +/-10 ℃, and keeping the temperature for 24-30 hours to perform ion nitriding treatment;
e. after nitriding is finished, naturally cooling the nitriding furnace to room temperature;
f: and taking out the nitrided brake ejector rod (1), and carrying out data detection on the brake ejector rod (1).
2. The process of claim 1, wherein the ion nitriding process comprises the following steps: the sealing groove (2) is of a circumferential sealing groove structure.
3. The process of claim 1, wherein the ion nitriding process comprises the following steps: the first protective sleeve (4) and the second protective sleeve (5) are both made of high-temperature-resistant metal materials.
4. The process of claim 1 or 3, wherein the ionic nitriding of the parking brake ejector pin of the railway vehicle is as follows: the first protective sleeve (4) and the second protective sleeve (5) are in transition fit with the two ends of the brake ejector rod (1).
5. The process of claim 1, wherein the ion nitriding process comprises the following steps: in the step c, the brake ejector rods (1) are arranged into 4 layers, and 60 pieces are arranged in each layer.
6. The process of claim 1, wherein the ion nitriding process comprises the following steps: and in the step e, the nitriding furnace is naturally cooled to room temperature for not less than 24 hours.
7. The process of claim 1, wherein the ion nitriding process comprises the following steps: in the step f, the data detection is to detect the length, the diameter and other classifications of the brake ejector rod (1).
Technical Field
The invention relates to the technical field of metal heat treatment, in particular to an ion nitriding process for a parking brake ejector rod of a railway vehicle.
Background
The parking brake ejector rod is a key part for basic braking of high-speed rails and urban rail vehicles, and is characterized by small part size, complex processing technology, high precision requirement and difficulty in controlling a geometric dimension detection method and process. The common nitriding processes in metal heat treatment include gas nitriding, liquid nitriding and ion nitriding. The existing brake ejector rod is nitrided generally by adopting a gas nitriding treatment process, and because the two ends of the brake ejector rod are of hole groove structures, the difference between the wall thickness of the brake ejector rod and other parts is large due to the special structures at the two ends, the skin effect is very easy to occur at the hole groove parts at the two ends in the nitriding treatment process, the phenomenon of local overheating stress concentration is generated, the size of the brake ejector rod in the length direction is increased due to stress release, and therefore the size of the brake ejector rod is irregular, the discreteness is large, and the deformation is difficult to control.
The patent with application number CN201710077858.1 discloses in the process of processing metal parts, in order to prevent the condition that the size of a non-nitrided surface is deformed and the size of high precision is out of tolerance due to long-time high-temperature treatment, different margins are left on the non-nitrided part and the nitrided part of the part before the part is nitrided, copper plating protection is carried out on the non-nitrided part, after the nitriding is finished, the copper layer of the non-nitrided part is firstly ground off and processed to the final size, and then the nitrided part is ground to the final size. This scheme technology is complicated, carries out the copper facing at non-nitrogenize face, then polishes the copper facing, not only increases the technology degree of difficulty, increases manufacturing cost moreover, causes the waste of metal copper resource, and the dust of the production of polishing also can cause air pollution to the workshop, still protects the nitrogenize face in addition when carrying out non-nitrogenize face and polish, treats that non-nitrogenize face finishes polishing and just can polish the processing to the nitrogenize face, and production processes is longer, and is of a specified duration, and production efficiency is low.
Therefore, it is necessary to design an ion nitriding process for the brake ejector rod of the rail vehicle parking, which can control the influence of ion nitriding treatment on the deformation of the part size as much as possible on the premise of realizing the control of the machining size process, ensure that the deformation of each size of the brake ejector rod after nitriding treatment is basically uniform and consistent, has no discreteness and ensures that machining is not needed any more after nitriding treatment.
Disclosure of Invention
The invention aims to overcome the defects in the prior art, and provides an ion nitriding process for a railway vehicle parking brake ejector rod, which aims to control the influence of ion nitriding treatment on the deformation of the size of a part as much as possible on the premise of realizing the control of a machining size process, achieve the purposes that the deformation of each size of the brake ejector rod after nitriding treatment is basically uniform and consistent, has no discreteness and ensures that machining is not needed any more after nitriding.
The technical scheme for realizing the purpose of the invention is as follows: before the ionic nitriding, the brake ejector rod is subjected to annealing after forging, tempering after rough turning and stress relief aging treatment before finish turning; the hardness of the brake ejector rod is HRC 33-35; one end of the brake ejector rod is provided with an internal thread hole, and the other end of the brake ejector rod is provided with a sealing groove; a first protective sleeve is sleeved at one end of the brake ejector rod, which is provided with an internal thread hole; a second protective sleeve is sleeved at one end of the brake ejector rod, which is provided with a sealing groove; the ion nitriding process comprises the following steps:
a. before nitriding treatment, performing blunting treatment on the sharp corner with the hole on the brake ejector rod;
b. a first protecting sleeve is sleeved at one end of the braking ejector rod with the internal thread hole, and a second protecting sleeve is sleeved at the other end of the braking ejector rod with the sealing groove;
c. putting the brake ejector rod sleeved with the first protective sleeve and the second protective sleeve into a nitriding furnace;
d. in the ion nitriding temperature rise stage, when the temperature of the brake ejector rod rises to 300 ℃, after heat preservation is carried out for 3 hours, the temperature is raised to 540 ℃ plus or minus 10 ℃, and the temperature is kept for 24-30 hours for ion nitriding treatment;
e. after nitriding is finished, naturally cooling the nitriding furnace to room temperature;
f: and taking out the nitrided brake ejector rod, and detecting the data of the brake ejector rod.
The seal groove is of a circumferential seal groove structure.
The first protective sleeve and the second protective sleeve are made of high-temperature-resistant metal materials.
The first protective sleeve and the second protective sleeve are in transition fit with the two ends of the brake ejector rod.
In the step c, the brake ejector rods are arranged into 4 layers, and 60 pieces are arranged in each layer.
And in the step e, the nitriding furnace is naturally cooled to room temperature for not less than 24 hours.
In the step f, the data detection is to detect the length, the diameter and other classifications of the brake ejector rod.
After the technical scheme is adopted, the invention has the following positive effects:
(1) according to the invention, the first protective sleeve is sleeved on one end of the brake ejector rod with the internal thread hole, and the second protective sleeve is sleeved on the other end of the brake ejector rod with the sealing groove, so that the uncontrollable deformation caused by the skin effect caused by the thin wall of the two ends and the special structure of the hole groove in the nitriding process of the two ends of the brake ejector rod is improved. The protective sleeve has the function of protecting the non-nitrided part from being nitrided and deformed while ensuring that the nitrided part is fully nitrided. After the implementation of the scheme, the deformation of the size of each part of the brake ejector rod is basically uniform and consistent, the deformation is small, and large discreteness does not occur, and particularly, the state and the size of the internal thread hole and the sealing groove of the brake ejector rod before nitriding treatment are basically maintained.
(2) The protective sleeve used by the invention is made of high-temperature-resistant metal materials, and the protective sleeve and the brake ejector rod are in transition fit, so that abrasion between the protective sleeve and the brake ejector rod in the sleeving process can be avoided, in addition, the protective sleeve can be repeatedly recycled, the operation is simple, convenient and fast, the working procedure duration is shortened, the working procedure steps are simplified, and the production rate and the qualification rate of products are effectively improved.
(3) According to the invention, the sharp corner of the hole on the brake ejector rod is subjected to blunting treatment before nitriding treatment, so that the situation that the sharp corner has skin effect during nitriding to form a melting point which generates a breaking notch during subsequent polishing treatment can be effectively prevented, and the occurrence of reject ratio is reduced.
Drawings
In order that the present disclosure may be more readily and clearly understood, reference is now made to the following detailed description of the present disclosure taken in conjunction with the accompanying drawings, in which
FIG. 1 is a schematic structural view of a brake carrier rod according to the present invention;
FIG. 2 is a cross-sectional view of the brake ram of the present invention;
FIG. 3 is a cross-sectional view of the brake pin being nitrided according to the present invention;
FIG. 4 is a labeled view of the brake carrier rod of the present invention;
FIG. 5 is a table of spot check data after nitriding the brake carrier rod.
The reference numbers in the drawings are as follows: 1 is a brake ejector rod, 2 is a sealing groove, 3 is an internal thread hole, 4 is a first protective sleeve, 5 is a second protective sleeve, A is a non-nitriding area, B is a non-nitriding area, and C is a non-nitriding area.
Detailed Description
(example 1)
The invention relates to an ion nitriding process of a railway vehicle parking brake ejector rod, which comprises the following steps:
a. before nitriding treatment, performing blunting treatment on the sharp corner of the hole on the
b. a first protecting sleeve 4 is sleeved on one end of the
c. putting the
d. in the ion nitriding temperature rise stage, when the temperature of the
e. after the nitridation is finished, naturally cooling the nitriding furnace to room temperature, wherein the time for naturally cooling the nitriding furnace to the room temperature is not less than 24 hours;
f: and taking out the nitrided
(example 2)
Referring to fig. 1 to 3, the brake device of the invention comprises a
(example 3)
Referring to fig. 3, the first protective sleeve 4 and the second protective sleeve 5 are both made of high temperature resistant metal materials, the first protective sleeve 4 and the second protective sleeve 5 are in transition fit with two ends of the
(example 4)
Referring to fig. 4 and 5, fig. 5 is the spot inspection data of the local dimension marked in fig. 4 after nitridation, and the following is the analysis of the nitridation process result:
content of inspection
Error range
Sample 1
Whether it is qualified or not
0.5
0.5(±0.1)
Caliper rule
0.51
0.52
Qualified
2.7
2.7/+0.1/0
Caliper rule
2.75
2.75
Qualified
5
5(±0.1)
Caliper rule
5.02
5.01
Qualified
19
19(±0.2)
Depth gauge
19.15
19.18
Qualified
22
22/+0.2/0
Depth gauge
22.13
22.12
Qualified
104
104/-0.2/-0.3
Depth gauge
103.77
103.76
Qualified
131
131(±0.5)
Caliper rule
131.07
131.09
Qualified
Φ30
Φ30(±0.5)
Caliper rule
30.00
29.98
Qualified
Φ19.5
Φ19.5/+0.05/+0.02
Micrometer
19.53
19.535
Qualified
Φ24
Φ24/+0.2/+0.1
Micrometer
24.17
24.18
Qualified
Φ63.5
Φ63.5(±0.3)
Caliper rule
63.50
63.50
Qualified
M20*1
M20*1
Screw plug gauge
√
√
Qualified
Through classified detection of 60 pieces of 4 layers, relevant data of two samples are extracted from the samples, and according to detection data analysis, the ion nitriding influences the size of the
The working principle of the invention is as follows: before nitriding, firstly forging the
The above-mentioned embodiments are intended to illustrate the objects, technical solutions and advantages of the present invention in further detail, and it should be understood that the above-mentioned embodiments are only exemplary embodiments of the present invention, and are not intended to limit the present invention, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
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