Some standard content:
ICS25.200
J36
JB
Mechanical Industry Standard of the People's Republic of China
JB/T4393-1999
Polyvinyl alcohol synthetic quenching agent||tt ||Polyvinylalcoholof quenchingmedis1999-06-24 Released
National Machinery Industry Bureau
Released
Implemented on 2000-01-01
JB/T4393—1999
Foreword
This standard is a revision of JB4393-87 "Technical Conditions for Polyvinyl Alcohol Synthesis Rate Fire Agent". During the revision, editorial changes were made to the original standard in accordance with relevant regulations, and the main technical content remained unchanged. This standard replaces JB4393--87 from the date of implementation. Appendix A of this standard is a reminder appendix.
This standard is proposed and coordinated by the National Heat Treatment Standardization Technical Committee. The organization responsible for drafting this standard: Beijing Mechanical and Electrical Research Institute. The responsible drafters of this standard: Yang Shufan and Malan. This standard was first published on May 22, 1987. Scope
Machine Industry Standard of the People's Republic of China
Polyvinyl alcohol synthetic quenching agent
Polyvinyl alcohol of quenching media This standard specifies the technical conditions for polyvinyl alcohol synthesis rate quenching agent, JB/ T43931999
replaces JB439387
This standard is applicable to the organic water-soluble flame retardant medium used for fire cooling of steel parts - a synthetic flame retardant agent with polyvinyl alcohol as the main component.
Quoted standards
The provisions contained in the following standards constitute provisions of this standard by being quoted in this standard. At the time of publication, the editions indicated were valid. All standards are subject to revision and parties using this standard should explore the possibility of using the latest version of the standard listed below. JB/T4392-1999 Method for determination of properties of water-soluble itching medium of organic matter 3 Preparation of raw materials
The main raw material used to prepare the synthetic itching agent is 17-18 polyvinyl alcohol (white solid powder). Its molecular structural formula is: -CHCH,
OH
Basic composition
The basic composition of the synthesis rate fire agent is shown in Table 1.
Name
Name
Polyvinyl alcohol
Anti-rust agent
Preservative
Defoaming agent
Water| |tt||Note: The product supply status is concentrated liquid.
State Machinery Industry Bureau 1999-06-24 approved form 1
CH,—CH.
oco
CH,
including||tt| |%
10
0.2
≥0.02
remainder
most
amount
2000-01-01 Implementation
5 Technical indicators
JB/T43931999
5.1 Appearance: colorless to light yellow, evenly dissolved liquid (translucent). 5.2 Solid content: 10%~12%
5.3 Conditional viscosity: 20~50s (based on Tu-1 viscometer). 5.4, ??density: 1.015~1.035g/cm2. 5.5 pH value: 6-8.
5.6 refractive index) 1.3470~1.3520.
5.7. Conductivity\;0.2~0.3S/m.
6 Sampling Methods
After the raw materials are dissolved and evenly prepared, sampling can be done at room temperature. When taking samples during storage, you can slowly insert a clean and dry glass tube with an inner diameter of 10~15mm and open at both ends into the middle of the container, then block the upper end of the glass tube, and move the liquid in the tube to a clean In the sample bottle, repeat this operation until the amount required for the measurement is obtained. : For each batch of polyvinyl alcohol synthetic itching agent, take 3 samples for analysis and testing, and use the average of the 3 samples as the analysis and test results.
Measurement items and methods
Measurement items and methods are in accordance with the relevant regulations of JB/4392. 8Packaging and storage
8.! The inner packaging should be in a plastic bag, and the mouth of the bag must be sealed tightly. The outer packaging should be in an iron drum or a cardboard drum (it can also be packed directly in a plastic drum). It should be intact and intact. The manufacturer, batch number, and production date should be marked, and a quality certificate should be attached. 8.2 During storage and transportation, protective measures against sun, heat, moisture, and freezing should be taken. Store in a dry and cool place. The storage temperature should be room temperature but not exceed 35°C.
8.3 Under the conditions specified in 8.2, the storage period is half a year (calculated from the date of shipment). If the storage time exceeds the shelf life, the product can still be used if its appearance and technical indicators meet the regulations. 1) is a reference index.
JB/T4393—1999
Appendix A
(Appendix of prompts)
Instructions for use of polyvinyl alcohol synthetic flame retardant
Because the product is concentrated Liquid cannot be used directly in production. What is used in production is a dilute solution. Based on the test and application of dilute solutions, the following points are summarized for users’ reference in order to rationally use dilute solutions (hereinafter referred to as fire liquids). Applicable scope of A1 polyethyl alcohol synthetic quenching agent. This quenching agent is mainly suitable for spray cooling or immersion cooling of the surface of steel workpieces. It can also be used for air furnace heating and overall thermal cooling; it is not suitable for salt furnace heating. Quenching and cooling (due to the large amount of inorganic salts brought into the hot workpiece, it will cause the decomposition and gelation of polyvinyl alcohol)
This quenching agent is mainly suitable for quenching medium carbon steel and low alloy steel. cool down. The applicable steel type can be determined based on the geometry, size and technical requirements of the workpiece, as well as the cooling performance of the fire liquid at different concentrations and temperatures, or by conducting experiments.
According to some current production data, mechanical parts made of the following steel grades can be fire-cooled with synthetic fire liquid (see Table A1). Table A1 Applicable scope of synthetic quenching fluid
Example
Species
45: 40 Cr; 45 Cr
50Mn
20 CrMo
40CrMnMo
42 CrMo; 35 CrMo
40MnB;45MnB
3 Cr2w8: Cr12
9 Crsi; 9 Cr3
42CrNi
40CrMnMo ; 40CrMo | ：gear; output
shaft
bearing raceway: camshaft
pin sleeve
shaft
crankshaft; rear half shaft
Fork flange shaft
Rolling
Screw
Drill joint
Drilling tools
Pipe parts
A2 polyethylene Preparation and heat treatment method of dilute solution of alcohol synthetic fire agent
High frequency barrier fire
Medium Ping fire
Latent carbon post-fire
Carbon-nitriding post-fire| |tt||The surface of the fire stuffing is zinc fire
Cihuo
Mid-palate rate fire
Itchy fire
Fire
Conditioning
Pinghuo liquid concentration
%
0.20.4
0.2-0.3
0.3-0.5
0.10.5
0.25~0.4
This high-rate fire agent is supplied as a concentrated liquid containing 10% to 12% polyvinyl alcohol. When used, water should be added to dilute it into aqueous solutions of different concentrations, 3
JB/T4393-1999
for the rate fire cooling of various workpieces. The method of preparing high-efficiency fire liquid is shown in the formula (A1): NWbzxZ.net
M
In the formula: M
The weight of the synthetic fire retardant concentrate, kg
N |
Control of A3 quenching liquid concentration
p
(AI)
Since the red-hot workpiece is constantly in contact with the quenching liquid, the content of polyvinyl alcohol in the liquid It also changes. Generally, as the use time increases, the concentration of the quenching liquid gradually decreases, and the cooling performance also changes (see Figure A1). In order to ensure the quality of heat-treated workpieces, the concentration of polyvinyl alcohol in the quenching liquid must be stabilized within an appropriate range. Since the quenching liquid usually contains a small amount of polyvinyl alcohol, generally 0.It is in the range of 1%~0.5%, so it is difficult to accurately control its concentration by measuring specific gravity, refractive index and conductivity. Currently, the most commonly used measurement method in Gencuo on-site production is the baking and weighing method, according to JB/T4392 In Chapter 4 of 1999, the total amount of peripheral matter contained in the quenching liquid was measured.
Solid content x (%) is calculated according to formula (A2): w,-w
||Container weight, more:
Sample and container weight after drying, g;
W.
W,-
Sample and container weight before drying, g.
8
800
700
600
500
400
300
200|| tt||100
15
20
(Test probe: @20mm silver ball)
25
30
Time|| tt||Figure A1 Cooling curves of polyvinyl alcohol aqueous solutions with different concentrations at 40°C 34
(A2)
Due to the oil, rust, etc. that are carried into the liquid along with the workpiece during the cooling process of Pinghuo Sundries, so when sampling, the water should be collected under the condition that the Pinghuo liquid is still. If necessary, filter the sample with filter paper before testing and then conduct the drying test. During continuous production and use, samples should be taken and measured at least once a week. According to the measurement results, the concentration of itchy fire liquid can be adjusted in time to maintain the stability of the ingredients.
Control of A4 quenching liquid temperature
JB/T4393—1999
According to the test and production conditions, it is shown that the temperature change of the quenching liquid has obvious changes in its cooling performance (see Figure A2 ): As the liquid temperature increases, the cooling rate slows down; when the liquid temperature is higher than 50°C, the cooling rate decreases significantly, and incomplete fire rate and low hardness often occur. Therefore, under normal circumstances, the liquid temperature should be controlled above room temperature, but should not exceed 45°C. In order to control the temperature of the quenching liquid, a cooler, a heater and a circulation device should be installed in the fire tank. A serpentine tube can also be placed in the fire tank for heating or cooling. Try to avoid heating the fruit with an electric heater or a red-hot iron block on the surface to prevent excessive burning and decomposition of the polyvinyl alcohol in the tank.
8
800
700
600
500
400
300
200|| tt||100
15
time s
20
(test probe: medium 20mm forged ball)
30
35| | tt | When the compound encounters inorganic salts such as salt and alkali, it will produce a gel phenomenon, which will change the cooling performance. Therefore, you should try to avoid bringing in salts and alkali during use. If the workpiece is cleaned with waves, the pH value will gradually increase. Therefore, the rate fire liquid should be managed by measuring the pH value to prevent the failure of the rate fire liquid gel. Use precision test paper in the pH range of 5 to 9 for measurement. The most suitable range is pH 6.5 to 7.5.
Defoaming, anti-corrosion and anti-rust of A6 fire liquid
During the use of A6.1, due to the spraying, circulation, stirring, etc. of the fire liquid, it is easy to produce a large amount of foam, causing itching fire Uneven cooling affects the firing quality of the workpiece. Therefore, in production, attention should be paid to using a circulating pump with appropriate technical specifications. The head should not be too high, preferably no more than 30m. When using propeller stirring, the rotation speed should be controlled below 450r/min. If you need to further eliminate foam, you can add a small amount of defoaming agent and drop it directly into the fire tank. The amount of defoaming agent used, such as Taikoo oil or SPG-10, should be less than 0.01%, which generally does not affect the cooling effect of the fire. Although A6.2 rate fire liquid has certain anti-corrosion capabilities, it is easy to multiply when exposed to bacteria at room temperature of around 28°C, and will gradually produce an odor, turn black in color, and become ineffective. In order to prevent the breeding of bacteria in the liquid in the tank and pipes, the fire liquid should be stirred or circulated once a day to extend the service life of the fire liquid. If you want to further improve the anti-corrosion effect because the temperature is too high, you can add a small amount of preservative (should be less than 0.2% sodium benzoate) into the tank. A6.3 quenching fluid contains a certain amount of anti-rust agent, which has good anti-rust performance. However, in the high temperature and high humidity season in southern my country, sometimes T parts will rust after being ignited. Control can be taken during the quenching operation. The final cooling temperature of the workpiece is adjusted to make the remaining moisture on the surface of the workpiece evaporate as quickly as possible. Usually the final quenching cooling temperature should be controlled at about 150~250℃, and the requirements can be appropriately controlled without affecting the fire technical conditions of the workpiece. For workpieces with complex shapes and small sizes, when the final quenching cooling temperature is difficult to control, a small amount of anti-rust agent (such as 0.05% sodium nitrite) can be added to the fire tank, which can significantly improve the anti-rust effect. A7 Quenching fluid replacement cycle and discharge
A7.1 Since the organic fire medium will inevitably age and deteriorate during use, it needs to be replaced within a certain period of time. However, under the condition that the rate, temperature and PH value of the fire liquid are strictly controlled and equipped with sedimentation and filtration devices, and the floating fire liquid is kept clean and without separation, the use time is generally 1 to 3 months. Each heat treatment production site It can be replaced according to its production situation. A7.2 When replacing the New Ze fire fluid, the pollution issue caused by the discharge of the old fluid must be considered. According to the Beijing Environmental Protection Monitoring Center, the biological oxygen consumption of the newly prepared 0.3% polyvinyl alcohol quenching solution is 68.4mg/L, which is lower than the national sewage discharge standard (100mg/L). If it is used, it may cause fire. When the concentration is high, it can be appropriately diluted with water and discharged after its biological oxygen consumption is lower than 100mg/L.Cooling curves of 1% polyvinyl alcohol aqueous solution at different temperatures A5 Preventing gelation and failure of quenching liquid
Polyvinyl alcohol in quenching liquid is an organic compound. When it encounters inorganic salts such as salt and alkali, it will produce gelation, which will change the cooling performance. Therefore, salt and alkali should be avoided as much as possible during use. For example, when the workpiece is cleaned, the pH value will gradually increase. Therefore, managing the quenching liquid by measuring the pH value can prevent the gelation of the quenching liquid from failing. The most suitable range is pH6.5-7.5 for determination using precision test paper in the pH range of 5-9.
A6 Defoaming, corrosion prevention and rust prevention of quenching liquid
A6.1 During use, a large amount of foam is easily generated due to the spraying, circulation and stirring of the quenching liquid, which causes uneven cooling of the quenching liquid and affects the quenching quality of the workpiece. Therefore, in production, attention should be paid to the use of circulating pumps with appropriate technical specifications, and the head should not be too high, preferably not more than 30m. When using propeller stirring, the speed should be controlled below 450r/min. If further foam elimination is required, a small amount of defoamer can be added and dripped directly into the cooling tank. The amount of defoamer used, such as Taiko oil or SPG-10, should be less than 0.01%, which generally does not affect the cooling effect of the cooling tank. A6.2 Although the cooling liquid has a certain anti-corrosion ability, it is easy to reproduce when it encounters bacteria under static conditions at room temperature of about 28°C, and it will gradually produce odor, turn black in color, and become ineffective. In order to prevent the reproduction of bacteria in the liquid in the tank and pipeline, the cooling liquid should be stirred or circulated once a day to extend the service life of the cooling liquid. If the temperature is too high and you want to further improve the anti-corrosion effect, you can add a small amount of preservative (should be less than 0.2% sodium benzoate) to the tank. A6.3 The quenching liquid contains a certain amount of rust inhibitor, which has good rust prevention performance. However, in the hot and humid season in southern my country, sometimes the parts rust after quenching. During the quenching operation, the method of controlling the final cooling temperature of the workpiece can be adopted to make the residual moisture on the surface of the workpiece evaporate as soon as possible. Usually, the final cooling temperature of quenching should be controlled at about 150~250℃, and the requirements can be properly controlled without affecting the technical conditions of the workpiece. For workpieces with complex shapes and small sizes, when the final cooling temperature of quenching is difficult to control, a small amount of rust inhibitor (such as 0.05% sodium nitrite) can be added to the quenching tank, which can significantly improve the rust prevention effect. A7 Replacement cycle and discharge of quenching liquid
A7.1 Since the organic quenching medium will inevitably age and deteriorate during use, it needs to be replaced within a certain period of time. However, under strict control of the quenching liquid, temperature and pH value and equipped with sedimentation and filtration devices, and under the condition of keeping the quenching liquid clean and free of deterioration, the service life is generally 1 to 3 months, and each heat treatment production site can replace it according to its specific production situation. A7.2 When replacing the new quenching liquid, the pollution problem of the discharge of the old liquid must be considered. According to the determination of the Beijing Environmental Protection Monitoring Center, the biological oxygen demand of the newly prepared 0.3% polyvinyl alcohol quenching liquid is 68.4 mg/L, which is lower than the national sewage discharge standard (100 mg/L). If it is used or the concentration of the quenching liquid is high, it can be appropriately diluted with water, and its biological oxygen demand is lower than 100 mg/L before discharge.Cooling curve A5 of 1% polyvinyl alcohol aqueous solution at different temperatures to prevent gelation and failure of the quenching liquid
Rate the polyvinyl alcohol organic compounds in the fire liquid when encountering inorganic salts such as salts and alkali A gel phenomenon will occur, which will change the cooling performance. Therefore, salt and alkali should be avoided during use. If the workpiece is cleaned with waves, the pH value will gradually increase. Therefore, the rate fire liquid should be managed by measuring the pH value to prevent the failure of the rate fire liquid gel. Use precision test paper in the pH range of 5 to 9 for measurement. The most suitable range is pH 6.5 to 7.5.
Defoaming, anti-corrosion and anti-rust of A6 fire liquid
During the use of A6.1, due to the spraying, circulation, stirring, etc. of the fire liquid, it is easy to produce a large amount of foam, causing itching fire Uneven cooling affects the firing quality of the workpiece. Therefore, in production, attention should be paid to using a circulating pump with appropriate technical specifications. The head should not be too high, preferably no more than 30m. When using propeller stirring, the rotation speed should be controlled below 450r/min. If you need to further eliminate foam, you can add a small amount of defoaming agent and drop it directly into the fire tank. The amount of defoaming agent used, such as Taikoo oil or SPG-10, should be less than 0.01%, which generally does not affect the cooling effect of the fire. Although A6.2 rate fire liquid has certain anti-corrosion capabilities, it is easy to multiply when exposed to bacteria at room temperature of around 28°C, and will gradually produce an odor, turn black in color, and become ineffective. In order to prevent the breeding of bacteria in the liquid in the tank and pipes, the fire liquid should be stirred or circulated once a day to extend the service life of the fire liquid. If you want to further improve the anti-corrosion effect because the temperature is too high, you can add a small amount of preservative (should be less than 0.2% sodium benzoate) into the tank. A6.3 quenching fluid contains a certain amount of anti-rust agent, which has good anti-rust performance. However, in the high temperature and high humidity season in southern my country, sometimes T parts will rust after being ignited. Control can be taken during the quenching operation. The final cooling temperature of the workpiece is adjusted to make the remaining moisture on the surface of the workpiece evaporate as quickly as possible. Usually the final quenching cooling temperature should be controlled at about 150~250℃, and the requirements can be appropriately controlled without affecting the fire technical conditions of the workpiece. For workpieces with complex shapes and small sizes, when the final quenching cooling temperature is difficult to control, a small amount of anti-rust agent (such as 0.05% sodium nitrite) can be added to the fire tank, which can significantly improve the anti-rust effect. A7 Quenching fluid replacement cycle and discharge
A7.1 Since the organic fire medium will inevitably age and deteriorate during use, it needs to be replaced within a certain period of time. However, under the condition that the rate, temperature and PH value of the fire liquid are strictly controlled and equipped with sedimentation and filtration devices, and the floating fire liquid is kept clean and without separation, the use time is generally 1 to 3 months. Each heat treatment production site It can be replaced according to its production situation. A7.2 When replacing the New Ze fire fluid, the pollution issue caused by the discharge of the old fluid must be considered. According to the Beijing Environmental Protection Monitoring Center, the biological oxygen consumption of the newly prepared 0.3% polyvinyl alcohol quenching solution is 68.4mg/L, which is lower than the national sewage discharge standard (100mg/L). If it is used, it may cause fire. When the concentration is high, it can be appropriately diluted with water and discharged after its biological oxygen consumption is lower than 100mg/L.
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