T/CSAE 71-2018Cyclic corrosion test methods of automotive assemblies and materials (English PDF)

Foreword

This standard was proposed by the Automotive Anticorrosion and Aging Branch of the China Automotive Engineering Society.

This standard is approved by the China Automotive Engineering Society.

This standard is under the jurisdiction of the China Automotive Engineering Society.

This standard was drafted. China First Automobile Co., Ltd. Technology Center, US Q-Lab Company China Representative Office, Chongqing Chang an Automobile Co., Ltd., Zhejiang Zhongtai Automobile Manufacturing Co., Ltd., Dongfeng Commercial Vehicle Technology Co., Ltd. Dongfeng Commercial Vehicle Technology Center, God Long Automobile Co., Ltd. Technology Center, BYD Auto Industry Co., Ltd., Nanjing Automotive Group Co., Ltd. Automotive Engineering Research Institute, Ann Huijiang Huai Automobile Co., Ltd., Automotive Engineering Research Institute of Guangzhou Automobile Group Co., Ltd., Shanghai Automotive Group Co., Ltd.

Passenger car company, Changan Ford Motor Co., Ltd., FAW-Volkswagen Automotive Co., Ltd., Pan Asia Automotive Technology Center Co., Ltd.

Chery Commercial Vehicle (Anhui) Co., Ltd., Chery Shanghai Technology Center, China First Automobile Co., Ltd. Tianjin Technology Development Branch, Qoros Auto, Institute of Metal Research, Chinese Academy of Sciences, Hainan Tropical Vehicle Test Co., Ltd., China Shipbuilding Industry Corporation, 725 Xiamen Branch of the Institute, the 59th Institute of China Ordnance Industry, Standards Technical Service (Shanghai) Co., Ltd., Shanghai China Testing Zhengqi Testing Technology Co., Ltd., Shanghai Tianxiang Quality Technology Service Co., Ltd., Suzhou Xinxue Standard Technology Service Co., Ltd., Shanghai Bohai Testing Technology Co., Ltd., Akzo Nobel (China) Investment Co., Ltd., Shanghai Kaimiter Chemical Co., Ltd., Wuhan University of Science and Technology, Beijing University of Science and Technology.

1 Scope

This standard specifies the cyclic corrosion test method for automotive parts and materials.

This standard applies to all types of automotive parts and materials, including metal, metal coatings,, and other conversion coatings.

Quality control, performance verification, process verification and product structure design verification for layer and other anti-corrosion.

This standard applies to cyclic corrosion tests of automotive parts and materials conducted in the laboratory.

2 Normative references

The following standards are essential for the application of this document. All dated references, all subsequent modifications (not the inclusion of errata content or revisions does not apply to this standard, but parties to agreements based on this standard are encouraged to study the use of these documents.

The possibility of the latest version.

GB/T 10125-2012 Artificial atmosphere corrosion test salt spray test GB/T 13452.2-2008 Determination of film thickness of paints and varnishes ISO 3574 commercial grade and stamping grade cold rolled carbon steel sheet ISO 4628-2 Evaluation of coatings and varnishes -- Determination of the extent , s Evaluation of the level of foaming ISO 4628-3 Evaluation of coatings and varnishes -- Determination of the extent , s Assessment of rust rating ISO 4628-4 Evaluation of coatings for lacquering and varnishing -- Assessment of the extent, number and size of general type of damage - Part 4.

Evaluation of cracking grade ISO 4628-5 -- Evaluation of coatings and varnishes -- Determination of s Evaluation of shedding grade ISO 4628-6 Evaluation of coatings and varnishes -- Determination of the extent , s Evaluation of the chalking grade of the tape method ISO 4628-7 -- Evaluation of coatings and varnishes -- Determination of s Evaluation of velvet powdering grade ISO 4628-8 Evaluation of coatings and varnishes -- Determination of the extent, and size of general type of damage - Part 8.

Scratch delamination and corrosion degree assessment ISO 4628-10 Evaluation of coatings and varnishes -- Determination of s Points. Filament Corrosion Rating ISO 8407 Corrosion of metals and alloys Corrosion of corrosion products in samples 2T/CSAE ××-2018

3 Terms and definitions

The following terms and definitions apply to this standard.

4 Test solution

The reagents used in this standard are those of analytically pure or analytically pure reagents.

The salt solution configured in this standard is a 1% sodium chloride solution, and the pH of the solution is adjusted to 4.0 ± 0.1 with 0.5 mol/L sulfuric acid.

Note 1. The pH value should be measured with a pH meter at 25 °C ± 2 °C, or precision pH test paper with a measurement accuracy of not less than 0.3.

Conduct daily testing.

Note 2. The solution is filtered prior to use to avoid solids in the solution clogging the device nozzle.

Note 3. The used spray solution should not be reused.

5 Test equipment

6 Sample

6.1 The type, quantity, shape and size of the sample used for the cyclic corrosion test are agreeable. The sample can be a part or a template.

6.2 Unless otherwise specified, the sample should be thoroughly cleaned before the test. The cleaning method depends on the nature of the sample material.

The process of surface and its dirt should not be carried out with abrasives or solvents that may etch the surface of the sample. Care should be taken to avoid recontamination after cleaning the sample.

6.3 Before the test, the test sample shall be vacant or filled with simulated samples, and the sedimentation rate of the salt solution and other test conditions shall be specified.

After the range, the sample can be placed in the test chamber and the test can be started.

6.4 The placement angle of the sample surface in the test chamber is very important. In the test chamber, if the sample is a flat specimen, the surface to be tested 15° to 25° from the vertical and 20° to the vertical as much as possible.

6.5 Specimens can be placed on different horizontal surfaces of the box, but they cannot touch the box, and the samples cannot be in contact with each other. Between samples the distance should not affect the salt spray in the box and fall freely on the surface of the test. Drops on the specimen or its support must not fall on other specimens. Correct Tests with a total test period of more than 96 h allow the sample to be displaced, but records are required.

6.6 The sample holder is made of an inert, non-metallic material. The material of the hanging sample cannot be made of metal, but the artificial fiber and cotton fiber are applied.

Dimensions or other insulating materials.

6.7 After the cyclic corrosion test, the operation specifications for the scratches of the sample are shown in Appendix A.

7 Test conditions

7.1 The appropriate test conditions should be selected according to the materials or products to be tested.

7.2 The recommended test conditions are CATC H (Corrosion Acceleration Test with Controlled Humidity) method, specific See Table 1 and Figure 1 for description.

Table 1

Step test operation

Temperature inside the box (°C) Relative humidity (%) Every step time (hh.mm) Step between Conversion Conversion time (hh.mm) Step 1 Spray 25±2 - 0.04 - -Step 2 Temperature and Humidity Control 25±2 45±5 1.56 Linear 1.26 Steps 1 to 2, repeat 4 times - - - - -Step 3 Temperature and Humidity Control 50±2 90±5 2.00 Linear 1.00 Step 4 Temperature and Humidity Control 50±2 70±5 2.00 Linear 1.00 Steps 3 through 4, repeat 3 times - - - - -Step 5 Temperature and Humidity Control 50±2 90±5 2.00 Linear 1.00 Step 6 Temperature and Humidity Control 35±2 20±5 2.00 Linear 1.30 4T/CSAE ××-2018

8 Test cycle

8.1 The test period shall be agreed upon according to the relevant technical requirements of the materials or products to be tested.

8.2 The test shall not be interrupted as much as possible within the specified test period. Only when the sample needs to be observed for a short period of time, the test chamber can be opened and opened.

The time and number of check boxes should be as small as possible.

8.3 If the test is terminated depending on the time at which corrosion begins to occur, the sample should be inspected frequently and the test terminated according to the inspection.

Therefore, these samples cannot be tested together with the samples scheduled for the test period.

8.4 The surface of the specimen for the intended test period may be visually inspected periodically. Visible corrosion of the sample, using tap water or adding surface activity A solution of the agent cleans the surface of the sample. The surface of the specimen cannot be destroyed during the process.

9 Results evaluation

10 Test report

10.1 The test report must state the evaluation criteria used and the test results obtained. If necessary, test each sample as a result, the average test result of each group of the same sample and the photograph of the sample.

10.2 The test report may include the following contents, depending on the purpose and requirements of the test.

a) the standard number and the relevant standards referenced;

b) the type of salt and water used in the test;

c) a description of the material or product being tested;

d) the size, shape, sample area and surface state of the sample;

e) preparation of the test specimen, including pre-test cleaning and protection against the edges of the specimen or other special areas;

f) description of known features of the overlay and surface treatment;

g) the number of samples;

h) the method of cleaning the sample after the test, if necessary, the weight loss caused by the cleaning;

i) sample placement angle;

j) the frequency and number of times the sample is displaced;

k) test cycle and intermediate inspection results;

l) in order to check the accuracy of the test conditions, the performance of the reference sample specially placed in the test chamber;

m) test temperature;

n) salt spray settling rate;

o) the pH of the test solution and the collection solution;

p) collecting the density of the solution;

q) Corrosion rate of the reference sample (mass loss, g/m2);

r) an unexpected situation affecting the test results;

s) Interval of inspection.

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Appendix A

(normative appendix) Specimen specification for specimen scratches A.1 Preparation A.1.1 Tool it is recommended to use the scratch tool shown in Figure A.1 with a blade width of 0.5 mm. The section of the coating after scratching is a rectangular incision, micro the picture shows that the coating scratches are complete, and the microscopic picture is shown in Figure A.2.

Figure A.1 Picture of the scratch tool

Figure A.2 Scratch tool scratch section picture

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A.1.2 Ruler

Any straight leg that is strong enough and strong for the scratch tool to guide the scratch operation.

A.1.3 scale

Any scale that is strong enough and strong to measure the length of the scratch, etc.

A.1.4 Tape

Use water resistant tape, as shown in Figure A.3, for edge sealing.

A.1.5 Samples to be tested the sample to be tested is a sample or a sample. It is recommended that each sample to be tested be used for parallel testing.

Unless otherwise specified, the sample size is 70 mm × 150 mm × (0.6 ~ 1.5) or 100 mm ×.200 mm × (0.6 ~ 1.5) mm.

The material, thickness, size and surface pretreatment of the board to be tested shall be consistent in all tests and represent the actual car as much as possible.

The condition of the parts. Any deviation of the parameters will result in errors in the test results.

A.1.6 Treatment of samples Unless otherwise specified, coated samples are prepared in accordance with GB/T 1727. The sample is subjected to the conditions specified in GB/T 9278.

State adjustment. Unless otherwise agreed, the specimen shall be at least regulated at a temperature of 23 ° C ± 2 ° C and a relative humidity of 50% ± 5%.

16 h.

Unless otherwise specified, the total thickness of the original dry coating of the sample shall be determined in accordance with one of the non-destructive methods specified in GB/T 13452.2.

Mm meter. Record and mark the damage state of the sample, make the original record, and take photos or record the camera if necessary.

Some samples will have hanging holes. During the test, try to make the hanging holes face downward to avoid contamination of the coating due to rust water at the hanging holes.

Figure A.3 Waterproof tape

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At the peripheral edge of the specimen, waterproof tape is used for edge sealing to avoid contamination of the coating by rust water generated by early corrosion of the edge of the specimen.

A.2 Regulations

A.2.1 Scratches should be at least 20 mm from the edge of the test panel and between the scratches. Make three scratches on the specimen, the two scratches are flat the "II" type straight line traveling in the longitudinal direction of the sample, and the third scratch is a straight line perpendicular to the long side. Scratches should reach the metal bottom through the coating material. The vertical scratches are 80 mm long and the horizontal scratches are 50 mm long. When placing the template in the test chamber, be careful to place two parallel scratches on top.

The scratch position is shown in Figure A.4.

A.2.2 The recommended scratch tool has a rectangular cross section and a metal substrate with a scratch width of 0.5 mm. Use other specifications Trace tools shall be agreed upon by the parties concerned. Scalpels, razors and other non-test-specific knives are not allowed for scratches.

A.2.3 For galvanized or galvanized steel sheets, the results of the corrosion test may vary greatly by the coating and plating. test the test should agree on the extent to which the scratches are scratched and the coating is applied.

A.2.4 After the specimen is scratched, the relevant corrosion test is put into the interval at most 1 h.

Figure A.4 Schematic diagram of the scratch position

35 mm 35 mm

45 Mm

80 Mm

30 mm

45 mm

25 mm 25 mm50 mm

200 mm 150 mm

20 mm 20 mm

20 mm

80 mm

25 mm

25 mm

10 mm 50 mm 10 mm

30 mm

Scratch scratches

30 mm

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Appendix B

(normative appendix) Technical specification for sample evaluation B.1 Preparation B.1.1 Scale A scale that is long enough and strong to measure the length of the scratch, etc.

B.1.2 Magnifying glass the magnification is 10 times.

B.1.3 Camera

The pixel is over 8 million.

B.1.4 Thickness Gauge Non-destructive magnetic thickness gauge, according to GB/T 13452.2-2008 "Determination of paint thickness of paint and varnish".

B.2 Regulations

Before the corrosion test, the sample shall be scratched according to Appendix A. After the corrosion test, the sample shall be tested after the test according to Section 9.

After the corrosion test, it is necessary not only to determine the corrosion range, but also to determine the extent to which the film loses adhesion. Method of evaluation it can be determined either by measurement and calculation, or by comparison with the level of the diagram. The implementation rules stipulate that the film layer is missing Focusing and corrosion are achieved by measuring and calculating the "scratch layer width" and "scratch corrosion width". For other damage states, such as the formation of bubbles, the formation of rust, the formation of cracks, coating shedding or pattern corrosion, can be according to ISO 4628 the standard is evaluated in the same manner.

B.2.1 Evaluation of Scratch Part - Measurement and Calculation of Scratch Layer Deviation Width D Vertical scratches. Take 6 test points on a scratch line that is 80 mm long. (Start at 15 mm from one end of the score line, Take a point of 10 mm per pitch for a total of 6 test points. The two endpoints of the scribe line are not used as test points).

Horizontal scratches. Take 4 test points on a scratch line with a distance of 50 mm. (Start at 5 mm from one end of the score line, Take a point of 10 mm per gap for a total of 4 test points. The two endpoints of the scribe line are not used as test points).

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step.

1. The maximum delamination width D on both sides of the scratch test point is recorded, that is, the maximum width at which the film loses the detachment force.

2. Calculate the coating delamination width D according to formula (1) (1) among them.

D in mm, scratch layer width (one side) W1 is the unit of mm, the maximum delamination width on both sides of the scratch test point;

W0 is the width of the original scratch in mm.

Note. If the range of loss of adhesion is not uniform, you can increase the number of measuring points (15 mm from one end of the score line) Start taking points, take a point of 5 mm each, for a total of 12 points. The two endpoints of the score line are not used as assessment points) and are then calculated using Equation 1.

B.2.2 Evaluation of scratched parts - measurement and calculation of scratch corrosion width C step.

1. Record the maximum corrosion width C on both sides of the scratch test point, ie the maximum width of corrosion of the film.

2. Calculate the coating scratch corrosion width C according to formula (2) (2) among them.

C in mm, scratch corrosion width (one side) W2 in mm, the maximum corrosion width on both sides of the scratch test point;

W1-W0

W2-W0

Figure 1 Schematic diagram of sampling points

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W0 is the width of the original scratch in mm.

Note 1. If the range of corrosion width is not uniform, the number of measurement points can be increased (15 mm from one end of the score line) Start taking points, take a point of 5 mm each, for a total of 12 points. The two endpoints of the scratch line are not used as assessment points), that is, tight sets Medium measurement point. Then use Equation 2 to calculate.

Note 2. Generally, for a sample with good corrosion resistance, the scratch layer width D is the same as the scratch corrosion width C, and it is not easy to distinguish.

Note 3. Generally, the sample with poor corrosion resistance has a scratch layer width D greater than the scratch corrosion width C, and whether there is rust.

It is easy to distinguish.

B.2.3 Evaluation of sc...