JB/T 6075-1992 Metallographic inspection method for titanium nitride coating
Some standard content:
Mechanical Industry Standard of the People's Republic of China
JB/T6074-92
Preparation, Cleaning and Evaluation of Corrosion Samples
Published on May 5, 1992
Implementation of the Ministry of Machinery and Electronics Industry of the People's Republic of China on July 1, 1993
Published
Mechanical Industry Standard of the People's Republic of China
Preparation, Cleaning and Evaluation of Corrosion Samples
1 Subject Content and Scope of Application
JB/T6074-92
This standard specifies the preparation of metal samples for corrosion tests, the removal of corrosion products and the evaluation methods of corrosion losses. This standard is applicable to various corrosion tests under laboratory conditions, and can also be applied to the preparation, cleaning and evaluation of various corrosion test samples under natural environmental conditions.
2 Samples
2.1 Sampling
2.1.1 Samples can be taken directly from the product or from the same batch of raw materials used to manufacture the product. 2.1.2 This standard does not include the sampling of the whole product. 2.2 Shape and size of the test specimen
2.2.1 The shape and size of the test specimen shall be determined by the test purpose, material properties and container used. The test specimen with a large ratio of surface area to mass and a small ratio of edge area to total area shall be used as much as possible. 2.2.2 The total surface area of \u200b\u200beach test specimen shall not be less than 10cm2. Two shapes of test specimens are recommended, and their specifications are as follows: Plate test specimen: 1\u00d7b\u00d7h, cm: 5.00\u00d72.50\u00d7(0.20~0.30) 3.00\u00d71.50\u00d7(0.15~0.30)
Circular test specimen: medium\u00d7h, cm: 3.80\u00d7(0.20~0.30) 3.00\u00d7(0.20~0.30)
2.2.3
2.2.4
The shape and specifications of the test specimens in the same batch shall be the same. For each test, at least three parallel specimens shall be taken. 2.3 Surface Condition Adjustment of Specimens
2.3.1
2.3.2
The surface of the specimen used for the corrosion test shall simulate the surface condition of the product as much as possible. Surface Condition Adjustment Steps of Specimens
Grind with metallographic sandpaper or diamond paste to remove burrs on the edge and surface of the specimen. Degrease the specimen in acetone, alcohol or hot alkaline cleaning agent. When there is an oxide film or rust on the surface of the specimen, it is generally cleaned by the chemical method in 3.2. After thoroughly cleaning the specimen with water, place it in anhydrous alcohol. d.
Dry.
2.4 Metallurgical Condition Adjustment of Specimens
The metallurgical condition of the specimen shall not be changed during the preparation of the specimen. If there is any change, it shall be corrected by subsequent heat treatment, machining or other methods.
2.5 Measurement and weighing of samples
The measurement and weighing of samples must be carried out after cleaning and drying. The size is accurate to 0.01cm* and the mass is accurate to 0.001g. 3 Method for removing corrosion products after sample testing 3.1 Electrolytic cleaning method
3.1.1 After wiping off the loose corrosion products on the surface of the sample, immerse the sample in the electrolyte for electrolysis. Approved by the Ministry of Machinery and Electronics Industry on May 5, 1992 and implemented on July 1, 1993
3.1.2 Electrolyte formulation and process
Sulfuric acid (H2SO
Organic corrosion inhibitor"Www.bzxZ.net
Distilled water
Temperature
Time
Cathode
Current density
Density 1.84)
28mL
JB/T6074\u201492
1000mL
75\u2103||t t||3min
Graphite or lead\
Sample
20A/dm
Note: 1) 0.5g/L di-o-toluene thiourea or hexamethylenetetramine can be used as corrosion inhibitor. 2) When lead is used as anode, lead may be precipitated on the sample, causing mass loss error. If the sample is resistant to nitric acid, the lead in the sample can be removed by briefly immersing the sample in 1:1 nitric acid. Although lead deposition may cause mass loss error, it is still used as anode material because its corrosion products are easy to remove. . 3.2 Chemical cleaning method
Use the solution formula and process in Table 1 according to different materials. Table 1
Metal materials
Stainless steel
Aluminum and aluminum alloys
Copper, nickel and their alloys
Tin and tin alloys
Magnesium and magnesium alloys
Zinc and zinc alloys
Cleaning method
Solution composition
\u246020% sodium hydroxide, 200g/L zinc powder
Stain 1
\u2463Hydrochloric acid (HCl density 1.19) 1000mL, antimony oxide (Sb:0s) 20g, tin fluoride (SnC1:) 50g\u2462 sulfuric acid (H,SO.density 1.84) 100mL, organic corrosion inhibitor 1.5mL, steamed filling water 1000mL
alternately impregnate 9
\u2460 nitric acid (HNO density 1.42) 100mL, steamed filling water 1000mL
\u2461 ammonium citrate 150g, distilled water 1000mL
impregnate \u2460 chromic anhydride (CrOs) 20g, phosphoric acid (H,PO, density 1.69) 50mL, distilled water 1000mL
\u2461Nitric acid (HNO, density 1.42)
Hydrochloric acid (HC1 density 1.19) 500mL, distilled water soak
1000mL
Sodium phosphate (Na:PO.) 150g, distilled water 1000 soak
Chromic anhydride (CrO), 150gSilver chromate (Ag:CrO) 10g, steaming water 1000mL
Alternately soak\u2460Acetic acid (99.5%) 10mL, distilled water 1000mL \u2461Ammonium acetate 50g, distilled water 1000mL
Saturated ammonium acetate (CH:COONH)
Alternate immersion\u2460Ammonium hydroxide (NH,OH density 0.90) 150mL, distilled water 1000mL
\u2461Chromic anhydride (Cr0:) 50g, nitric acid
Silver (AgNO,) 10g, distilled water 1000mLTreatment conditions
Temperature \u2103
Boiling
Room temperature
Room temperature
Room temperature
Boiling| |tt||Boiling
Boiling
Room temperature
Boiling temperature
Time min
10~60
5~10
Until clean
Until clean
10~20
1~10
Pay attention to safety
The solution must be stirred vigorously, or the sample can be scrubbed with
Eraser or wooden tools
Organic corrosion inhibitor is hexamethylene
tetramine or thiourea
It can also be used Method \u2460 in steel
If there is still a film, immerse it in \u2461
and clean it for 1min
Most of the corrosion products should be removed before treatment
It is best to use electrolytic cleaning method
Chromic anhydride is not allowed to contain sulfate. In the preparation, silver nitrate is dissolved and then added to boiling chromic acid
3.3 Mechanical cleaning method
JB/T607492
This method can be used to replace or supplement the chemical cleaning method to remove attached sediments. A soft scraper or fiber bristle brush should be used to avoid damaging the sample matrix.
3.4 \u200b\u200bThe samples cleaned by the above methods should be cleaned in running water and gently scrubbed with a brush. If necessary, they can be repeatedly cleaned and soaked. The cleaned samples are placed in anhydrous alcohol, taken out and dried, and then placed in a dry coal dryer to cool to air temperature before weighing. 4 Evaluation of Corrosion Damage
4.1 Calculation of Corrosion Rate
4.1.1 Regardless of the cleaning method used, there is a possibility of damaging the base metal, which causes errors in the corrosion rate measurement. In order to correct this, one or more cleaned and weighed samples can be used. Re-clean and weigh using the same method, and the corrected mass loss value is calculated according to formula (1).
W=(W,- W2)-(W,-Ws)
Wherein: AW-corrected mass loss value, g; W,--mass of the sample before the corrosion test, g; W--mass of the sample after the corrosion test and removal of corrosion products\u00b7g; W,--mass of the sample after re-cleaning, g
For more accurate correction methods, see Appendix A (Supplement). 4.1.2 Calculate the average corrosion rate or the corrected corrosion rate according to formulas (2) and (3). K(WW)
R=K(W.-2Wa+W.)
Wherein: \-corrosion rate;
R-corrected corrosion rate;
K constant (see 4.1.3);
W, mass of the sample before the corrosion test, g, accurate to 0.001g; Wr
--mass of the sample after removing corrosion products, g, accurate to 0.001g; W,--mass of the sample after re-cleaning, g, accurate to 0.001g; S--surface area of \u200b\u200bthe sample, cm2. Accurate to 0.01cm2; T corrosion test time.h. Accurate to 0.01h; D density, g/cm
4.1.3 When T, S, W, and D are in the units specified in Article 4.1.2, the corrosion rate may be expressed in multiple units using the following appropriate K values. Corrosion rate unit
mm/a (millimeter/year)
(m/a (micrometer/year)
pm/s (picometer/second)
g/(mh) gram/(meter hour)
mg/(dmd) [mg/(dm2.day)
\u03bcg/(ms) microgram/(meter2second)]
K value
8.76\u00d710
8.76\u00d7107
2.78\u00d7106
1.00\u00d710*\u00d7D
2.40\u00d710\u00b0\u00d7D
2.73\u00d710\u00d7D
\u00b7 (3)
4.1.4 In 4.1.3, when calculating the corrosion rate in the last three units, there is no need to find the material density D value. The density of the constant K is exactly the same as the D low pin in the corrosion rate formula.
4.1.5 If necessary, these constants can also be used to convert the corrosion rate from one unit to another. In order to convert a corrosion rate in one unit to a corrosion rate in another unit, you can multiply it by K,/K for conversion. For example: 3
JB/T6074\u201492
2.78\u00d7106
1 mm/a=1x-
8.76\u00d7104
pm/s
When pitting corrosion exists, the corrosion rate calculated from the mass loss will be in error, and the corresponding pitting corrosion assessment method can be selected. 4.2
4.3 Other methods for assessing corrosion damage
4.3.1 Appearance Assess the change in appearance through rust, discoloration or oxidation. Mechanical properties If the cross-sectional area of \u200b\u200bthe specimen (measured value before the corrosion test) is reduced due to extensive corrosion, it will cause a decrease in tensile strength. 4.3.2
Local corrosion (such as cracking) can also cause Reduction in tensile strength and elongation. 4.3.3 Electrical properties Cracking and pitting can cause a reduction in apparent conductivity. Metallographic examination Separation, peeling, cracking or intergranular corrosion can be evaluated by preparing metallographic specimens of the surface. 4.3.4
5 Report
The report should include the sample composition, size, metallurgical conditions, surface preparation and cleaning methods of corrosion products after the test, as well as the evaluation results of corrosion damage.
JB/T607492
Appendix A
Method for accurate determination of mass loss
(Supplement)
A1 Repeat the cleaning several times, weigh after each cleaning and draw a curve of the relationship between mass loss and the total cleaning time or the number of cleanings. See Figure A1. The vertical bar at the inflection point of the curve is the mass loss caused only by the removal of corrosion products. This method is particularly suitable for electrolytic cleaning. Mass of corrosion products removed
Removed substrate
Removed corrosion products
Cleaning time
Figure A1
Additional notes:
Relationship between mass loss and cleaning time during cleaning This standard was proposed and coordinated by the Wuhan Materials Protection Research Institute of the Ministry of Machinery and Electronics Industry. This standard was drafted by the Wuhan Materials Protection Research Institute. The main drafters of this standard are Yu Hongying and Fang Yisan. China
Mechanical Industry Standard
Preparation, Cleaning and Evaluation of Corrosion Test Specimens
JB/T 6074\u201492
Published and distributed by the Mechanical Standardization Research Institute of the Ministry of Machinery and Electronics Industry Printed by the Mechanical Standardization Research Institute of the Ministry of Machinery and Electronics Industry (PO Box 8144, Beijing 100081)
Copyright reserved
No reproduction allowed
Format 880\u00d712301/16
Printing sheet 1/2
Word count 10,000
First edition in September 1992
First printing in September 1992
Print run 00,001\u2014700
Price 1.20 yuan
Serial number 0637||tt ||Standard of the Machinery Industry of the People's Republic of China
JB/T6075\u201492
Titanium Nitride Coating
Published on May 5, 1992
Metallographic Inspection Method
Implementation on July 1, 1993
Published by the Ministry of Machinery and Electronics Industry of the People's Republic of China
Standard of the Machinery Industry of the People's Republic of China
Titanium Nitride Coating
Subject Content and Scope of Application
Metallographic Inspection Method
JB/T6075\u201492
This standard specifies the metallographic inspection method of titanium nitride coating. This standard is applicable to the inspection of the metallographic structure, thickness and hardness of physical vapor deposition titanium nitride coating on high-speed steel. This standard is also applicable to the inspection of the metallographic structure and thickness of titanium nitride coating on other substrate materials (carbon steel, high alloy steel, cemented carbide, stainless steel, copper, etc.).
2 Reference standards
GB9451
GB9790
JB/T5069
EB6462
3 Sample preparation
Determination of the total hardened layer depth or effective hardened layer depth on thin surfaces of steel parts Metallic coatings and other related coatings Vickers and Knoop microhardness test methods for metallographic inspection of infiltrated metal layers of steel parts Microscopic measurement of the thickness of metal and oxide coatings in cross sections According to the provisions of Chapter 4 of JB/T5069.
3.1 Sampling
3.1.1 Take samples from representative parts of the product. For non-flat surface coatings, chrome or nickel plating is required before inlaying. The cross section cut during inlaying should be perpendicular to the coating to be tested. 3.1.2 Substitute test specimens
3.1.2.1 Substitute test specimens with the same material, same process and same batch as the product, with the recommended size of 10mm\u00d74mm\u00d720mm10mm)3.1.2.2 Two or more substitute test specimens are separated by nickel sheets and clamped for sample preparation. 3.1.3 Oblique section test specimens
According to Article 3.1.1 of GB9451.
3.2 Grinding and polishing of samples
3.2.1 Clamp (embed) the sample and lightly grind it with grinding wheel, pre-grinding disc and sandpaper in turn. The grinding direction is about 45\u00b0 with the coating. Rotate the sample 90\u00b0 each time you change the sandpaper
3.2.2 Polish with polishing powder or W10, W5 diamond polishing paste first, then clean and polish with water 4 Coating structure inspection
4.1 Before etching the sample, magnify 800~1000 times to check the uniformity, continuity and matrix bonding of the coating, pores and loose structure. 4.2 Etch with 3% nitric acid alcohol solution to show the matrix structure. 4.3 Use coating etchant to show the coating microstructure. The etchant is composed of: HO2 as the base, add appropriate amount of complexing agent and corrosion inhibitor, and adjust the pH value to 9~10 with NaoH10% aqueous solution, and use it as soon as it is prepared.
Erosion parameters are shown in the table below
Approved by the Ministry of Machinery and Electronics Industry on May 5, 1992 and implemented on July 1, 1993
Temperature \u2103
30~35
8~10
JB/T6075-92
20\uff5e25
25~30
Use the two reagents in 4.2 and 4.3 to erode the specimens successively. When available, the matrix and coating structures can be displayed. The structures of high-speed steel coating specimens displayed by different etchants are shown in Figures 1, 2 and 3. Figure 1 shows the matrix Organization
Etchants 3% nitric acid alcohol solution
Magnification 1000
Figure 2 shows the coating organization
Etchants coating etchants
Magnification 1000
Figure 3
JB/T607592
Shows the matrix and coating organization at the same time
Etchants 3% nitric acid alcohol solution + coating etchantsMagnification 1000
4.6 The coating electron scanning image is still a columnar product, and the phase composition line scanning and coating structure analysis coating is TiN and Ti.N, see Figure 4, Figure 5A
4 Electronic scanning of coating
Magnification
Accelerating voltage
5 Coating thickness measurement
8000
25kv
Use 3% nitric acid alcohol solution etchant
Figure 5
Magnification
Accelerating voltage
Detected X-ray spectrum
Probe current
Coating composition line scanning
6000
25kv
Ti-L\u03b1
1\u00d710-6A
15kv
N-Ka
2.5\u00d7106A
The cross-sectional sample is measured according to GB6462. Magnify 800-1000 times under a microscope, and the thickness from the surface to the substrate boundary is the coating thickness 5.1
5.2 Oblique section specimen, magnify 500-1000 times under a microscope, and the thickness from the surface to the substrate boundary is the extended coating thickness. The coating thickness is calculated according to the following formula in GB9451.
e=Lsin\u03b1
Where: e\u2014coating thickness\u00b7um;
L\u2014extended coating thickness, \u03bcm;
\u03b1\u2014\u2014module angle 5\u00b0~15\u00b0
JB/T6075\u201492
The coating thickness is measured at 3-5 points in the same field of view and the arithmetic average is taken. 5.4 Measure the coating thickness (micrometer) and read to one decimal place. The wear-resistant coating thickness is \u22651.5\u03bcm, and the decorative coating is 0.5\u03bcm. 5.5
Determination of coating hardness
Measure the hardness on the coating surface, and the operation method shall be carried out in accordance with GB9790. The surface roughness Ra of the sample is 0.32\u03bcm.
The sample needs to be specially coated, and the coating thickness is \u22655\u03bcum. The test force is 0.147~0.245N.
Wear-resistant coating thickness 1800HV
Test report
The titanium nitride coating report should include the following: coating equipment, substrate material and process parameters: a.
Coating structure and defects;
Coating uniformity and thickness (the test surface must be indicated); c.
Coating hardness;
e. Others.
Additional instructions:
This standard is proposed and managed by the Wuhan Materials Protection Research Institute of the Ministry of Machinery and Electronics Industry. This standard is drafted by the Wuhan Materials Protection Research Institute and Shanghai Tool Factory. The main drafters of this standard are Li Ruiju, Yi Renquan and Jin Dayi. A1 Test purpose
JB/T607392
Appendix A
Planned intermittent corrosion test method
(reference)
To examine the effect of test time on solution corrosivity and metal corrosion rate, and to select the best test cycle based on this. A2 Test method
A2.1
Take four groups of specimens, with at least 2 pieces in each group. All four groups of specimens should be placed in the medium of the same container for testing. If the container is not large enough, one specimen can be taken from each group and placed in one container for testing, or several containers can be used for parallel testing under the same conditions. A2.2 The test time of the four groups of samples is arranged as shown below: Group
Sample port Group
Group III
Group AIV
Test time
Ht+a
Groups I, II, and III start the test at the same time; Group I is a full-course test (test time is t+\u03b1), Group II is a long-course test (test time is t), and Group III is a short-course test (test time is \u03b1). When the test reaches t, the group V sample is placed in the above solution to start the test, and the test time is b (b=a).
A2.3 All tests are carried out in accordance with this standard, and the corrosion losses (weight loss per unit area) of the four groups of samples are used as the evaluation basis. A2.4 Evaluation
A2.4.1
A2.4.2
Assume that Rt+a, Rt, Ra, and Rb. are the corrosion losses of the four groups of samples I, II, III, and IV, respectively, and R. =R++a-Rto. The conditions that occur during the test are determined according to Table A1 and Table A2. Table A1
Judgment of conditions during corrosion test
Corrosivity of solution
Metal corrosion rate
No change
Decline
Increase
No change
Decline
Increase
R-Re
Rb
Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.