Some standard content:
This is a revision of JB/T9199-1999-1989 Technical Requirements for Anti-seepage Paints. During the revision, the original standard was edited according to relevant regulations. The main technical content has not changed. This standard replaces ZBG51108-1989 from the date of implementation. This standard is proposed and managed by the National Technical Committee for Heat Treatment Standardization. The responsible drafting unit of this standard: Wuhan Institute of Material Protection. The responsible drafters of this standard: Zhang Lian, Zhang Dengyue, Zou Yue. This standard was first issued on February 27, 1989. The standard specifies the general technical requirements for anti-seepage paints. JB/T9199—1999
Replaces ZBG51108—1989
This standard applies to various anti-seepage coatings that play a local anti-seepage role on workpieces during gas and solid chemical heat treatment. This standard does not include anti-seepage coatings that play a long-term anti-seepage role and anti-seepage coatings that play an anti-seepage role in molten salt. 2 Reference standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard is published, the versions shown are valid. All standards will be revised, and parties using this standard should explore the possibility of using the latest versions of the following standards. GB/T1750--1979 Determination of coating leveling property GB3095-1982 Atmospheric environment quality standard JB/T3999--1999 Carburizing and carbonitriding of steel parts Fire tempering JB/T4215-1996 Boronizing
JB/T8418--1996 Powder metal infiltration
3 Definitions
This standard adopts the following definitions.
3.1 Anti-seepage
Measures to prevent the active atoms produced in the penetrant from penetrating into the surface of the workpiece during chemical heat treatment. 3.2 Anti-seepage surface
The surface of the workpiece that needs to be anti-seepage during chemical heat treatment. 3.3 Anti-seepage coating
Coating that is applied on the surface that needs to be anti-seepage and plays an anti-seepage role during the chemical heat treatment process, mainly composed of a penetration barrier, a binder and a loosening agent.
3.4 Anti-seepage coating
The covering layer formed by applying anti-seepage coating on the surface of the workpiece. 4 Classification
4.1 Classification of coatings and coating removal methods
4.1.1 Coatings are divided into the following types according to their anti-seepage effects: a) Anti-carburizing coatings;
b) Anti-nitriding coatings;
c) Anti-carbonitriding coatings;bzxz.net
Approved by the State Bureau of Machinery Industry on June 24, 1999 and implemented on January 1, 2000
d) Anti-boronizing coatings;
e) Anti-chromium coatings;
f) Anti-aluminum coatings.
JB/T 9199—1999
4.1.2 The removal methods of anti-seepage coating after use are divided into the following four categories: Category 1: During quenching or air cooling, the coating on any part can peel off by itself, Category 2: Water washing or self-powdering
Category 3: Mechanical removal (such as sandblasting); Category 4: Chemical removal (such as acid or alkali solution cleaning). 4.1.3 According to the thinness and viscosity of the coating at room temperature, it is divided into two categories: Type A anti-seepage coating: a tumbled body prepared with organic or inorganic binders. Type B anti-seepage coating: a clay-like coating.
4.2 Classification mark
a) A——indicates anti-corrosion coating,
b) Penetrating elements are represented by other chemical element symbols, such as: C-carbon; N-nitrogen, B-boron, Cr-chromium; c) Coating binders are represented by the following numbers: 0-inorganic binder; 1-organic binder; 2-organic plus inorganic binder; d) After chemical heat treatment, the coating is removed from the workpiece surface and represented by the category number of the removal method (see 4.1.2). 4.3 Classification and marking of coatings
The complete classification and marking that characterizes the properties of coatings are: A[1] -[ -3]
Coating removal method
Coating binder properties
What elements are prevented from penetrating
Anti-seepage coatings
Example 1: For a certain anti-carburizing coating, the binder of the coating is inorganic. After carburizing, it is removed by sandblasting. The classification and marking of this coating is: AC-0-3
Example 2: For a certain anti-nitriding coating, the coating uses an organic binder. After nitriding, the coating self-powders. The classification and marking of this coating is: AN-1-2
5 Technical requirements
5.1 Anti-seepage performance
The anti-seepage ability of the coating can be evaluated from two aspects: one is the thickness of the anti-seepage layer of the coating; the other is the hardness of the anti-seepage surface. This standard selects the latter and specifies the qualified index of the anti-seepage ability of the coating. 5.1.1 The anti-seepage surface of the coating shall have significant anti-seepage performance after chemical heat treatment, that is, the anti-seepage surface can be machined by turning, milling, planing and other machining.
5. 1. 2 The anti-seepage performance of the coating is divided into two cases according to the characteristics of the permeation layer, and is measured by the hardness resistance rate or the maximum hardness value Hmx allowed at the coating of the anti-seepage coating.
5. 1. 2. 1 For anti-carburization and anti-carbonitriding coatings, the hardness resistance rate is used to represent it, and h ≥ 80% is specified as qualified. The h value is calculated according to formula (1):
Where: y
Hardness of the core of the workpiece;
(1)
Hardness of the anti-seepage surface of the workpiece.
JB/T 9199-1999
For example: after carburizing or carbonitriding quenching of 20CrMnTi steel, when the core hardness is 25HRC and the anti-seepage surface hardness is 27HRC or 30HRC, the h values are 92% and 80% respectively, which are qualified. When the hardness of the anti-seepage surface is higher than 30HRC, h<80%, which is unqualified. 5.1.2.2 For anti-nitriding, anti-chromizing, anti-aluminizing and anti-borizing, it is stipulated that the maximum hardness Hmx of the workpiece surface coated with anti-seepage coating is not higher than 320HV0.1 or 320HV10, that is, Hmax≤320HV0.1 or 320HV10, the coating is qualified; Hmax≥320HV0.1 or 320HV10, then the coating is unqualified.
For example: After 38CrMoAl steel is quenched and nitrided, the hardness of the core is 270HV10, and the surface hardness of the anti-nitriding treatment is 320HV10, that is, the quality of the anti-nitriding coating is qualified.
5.2 Anti-seepage coating and other related properties
5.2.1 Coating thickness
The coating thickness depends on the quality and process of the coating (including type A and type B, the same below), and should generally be (0.2~3) mm to ensure the anti-seepage effect.
5.2.2 Suspension performance of type A coating
Type A coating should be easy to stir. The suspension ratio of the stirred type A coating should be greater than 0.8 within 8 hours (tested according to 6.2). 5.2.3 Brushing performance of type A coating
Type A coating should be easy to brush, and the brushing index M should generally be 5~6.5 (tested according to 6.3). 5.2.4 Leveling of Type A coating
The leveling of coating is measured according to GB/T1750, and is measured by the time required for Type A coating to be evenly hooked, smooth and wrinkle-free on the surface of the workpiece. If there is wrinkle, it is unqualified.
5.2.5 Drying performance of coating
After coating, the coating should not crack or peel during drying. Under natural drying conditions, the coating should be dried within 8 hours until it can be put into the furnace for use; under baking conditions (80℃～90℃), the coating should be dried within 4 hours.
5.2.6 Strength of coating after drying
A steel sample with a dried coating of 10mm×5mm is freely dropped from a height of 1m onto the cement floor. Except for the impact surface facing the ground, other parts should not fall off or crack obviously. 5.2.7 Paint corrosion on metals
The paint applied on the workpiece should not cause corrosion to the substrate before and after chemical heat treatment, and the workpiece should be free of corrosion spots when inspected under a 4x magnifying glass.
5.2.8 Effective anti-seepage period of the coating
After the workpiece is coated with the paint, it should not lose its original anti-seepage ability after being left in the air for 72 hours. 5.2.9 Storage period of the paint
The paint is stored in a sealed container and should not lose its original performance within the specified storage period. 5.2.10 Environmental protection
The paint should not have a harmful effect on the environment and human body. The harmful gases generated must comply with the relevant provisions of GB3095 before they can be discharged into the atmosphere. The paint should not spontaneously ignite below 100°C. 6 Test methods
6.1 Paint sampling method
First, stir the paint evenly, and then take the paint from the center of the container. 6.2 Type A paint suspension test method
Stir the paint evenly, pour it into a 100mL glass measuring tube and let it stand for 8h, observe the suspended matter layer height, and calculate it according to formula (2): 1091
Where: U---paint suspension ratio;
H--suspended matter layer height;
H. —paint original height.
6.3 Test of Type A paint brushability
JB/T9199—1999
（2）
Use NDT-1 type rotational viscometer to test. First, measure the viscosity value ns of the paint when the viscometer rotates at a speed of 6 r/min, and then measure the viscosity value nso of the paint when it rotates at a speed of 60 r/min. The paint brushability index M is calculated according to formula (3): M=n
6.4 Test of anti-seepage performance
（3）
6.4.1 The test rod of anti-carburizing and anti-carbonitriding paint is specified to be made of 20CrMnTi steel with a size of $10mm×（50～60）mm. After quenching, measure the Rockwell hardness of the core and anti-seepage surface of the sample. 6.4.2 The test rod of anti-nitriding paint is specified to be 38CrMoAl with a size of 20mmX20mm. The test rods for anti-seepage chromium and anti-seepage boron coatings are specified to be made of 45# steel with a size of $20mm×3mm. The Vickers hardness value (HV10) or microhardness value (HV0.1) of the core and the anti-seepage surface is measured.
6.4.3 The test of the thickness and hardness of the anti-seepage layer on the anti-seepage surface shall be carried out in accordance with JB/T3999, JB/T4125, JB/T8418, etc. 7 Marking, packaging, storage and transportation
7.1 The coating packaging shall be moisture-proof, safe and reliable. The coating shall be packaged and sealed in bottles or plastic barrels. 7.2 The coating packaging shall have firm and obvious markings, including: product name, model, grade, trademark, net weight, batch number, manufacturer, date of manufacture and expiration date.
7.3 When storing and transporting the coating, it shall be protected from rain and moisture. 1092
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