ASTM D6665-24
Standard Practice for Evaluation of Aging Resistance of Pre-stressed Prepainted Metal in a Boiling Water Test
- Standard No.
- ASTM D6665-24
- Release Date
- 2024
- Published By
- American Society for Testing and Materials (ASTM)
- Latest
- ASTM D6665-24
- Introduction
Analysis of the Standard's Core Content
ASTM D6665-24 specifies a standardized test method for evaluating the cracking and adhesion loss of coatings on pre-coated metals after mechanical stress by accelerated aging in boiling water. This standard is applicable to all types of pre-coated metal sheets that have undergone forming processes such as stamping and bending.
Technical Principles and Test Value
Residual stresses generated during the processing of pre-coated metals can lead to potential failure risks in coating systems. The standard adopts the accelerated aging method of immersion in boiling water at 100℃ for 15 minutes and evaluates durability through the following failure modes:
Failure type Detection method Judgment standard Coating cracking Visual inspection with 10x magnifying glass No visible cracks Adhesion loss Pressure-sensitive tape peel test No coating falling off Blooming phenomenon Visual observation No whitening of the surface
Key equipment parameter requirements
The standard places precise technical requirements on test equipment, especially on adhesive tape parameters, which must strictly comply with the following:
- Tensile strength: 26.3-52.6N/10mm
- Elongation: 10%-40%
- Peel strength: 3.28-4.93N/10mm
- Total thickness: 0.041-0.066mm
3M Scotch® 681 tape is recommended as the standard test material.
Test Operation Specifications
- Prepare specimens pretreated according to D2794/D4145/E643 standards
- Record initial state (cracking/blooming/adhesion)
- Immerse in boiling water bath for 15±1 minutes
- Repeat test after drying and cooling at room temperature
Standard Evolution Analysis
Since its initial publication in 2001, the standard has been revised twice, in 2009 and 2019. The 2024 edition has the following major updates:
- Clarify the technical parameter range of adhesive tapes
- Add WTO/TBT Statement of Principles for Standardization
- Detail the content requirements of the test report
Implementation Recommendations
1. Sample preparation stage: Ensure that the degree of mechanical deformation is consistent with the processing technology of the final product
2. Test Environment Control: Use deionized water to prevent the effects of mineral deposits.
3. Result Evaluation: It is recommended to conduct a comprehensive evaluation in conjunction with the D2794 impact test.Typical Application Case: Through this test, an automotive parts manufacturer discovered that the epoxy-polyester hybrid coating had microcracks at the bend. After optimization, the product's outdoor service life was increased by 30%.
ASTM D6665-24 Referenced Document
- ASTM D2794 Standard Test Method for Resistance of Organic Coatings to the Effects of Rapid Deformation (Impact)
- ASTM D4145 Standard Test Method for Coating Flexibility of Prepainted Sheet
- ASTM E643 Standard Test Method for Ball Punch Deformation of Metallic Sheet Material
ASTM D6665-24 history
- 2024 ASTM D6665-24 Standard Practice for Evaluation of Aging Resistance of Pre-stressed Prepainted Metal in a Boiling Water Test
- 2019 ASTM D6665-09(2019) Standard Practice for Evaluation of Aging Resistance of Pre-stressed Prepainted Metal in a Boiling Water Test
- 2009 ASTM D6665-09(2014) Standard Practice for Evaluation of Aging Resistance of Pre-stressed Prepainted Metal in a Boiling Water Test
- 2009 ASTM D6665-09 Standard Practice for Evaluation of Aging Resistance of Pre-stressed Prepainted Metal in a Boiling Water Test
- 2001 ASTM D6665-01 Standard Practice for Evaluation of Aging Resistance of Pre-stressed Prepainted Metal in a Boiling Water Test
