What is the difference between ASTM B117 and ASTM G85?

 

ASTM B117 is a common salt spray test standard used to evaluate the corrosion resistance of metals and metallic coatings. It was developed by the American Society for Testing and Materials (ASTM) and is a widely accepted standard. The purpose of the ASTM B117 test is to simulate corrosion in a real environment by exposing the performance of the material in a salt spray environment. The test conditions consisted of spraying the specimens with a 5% saline solution at a constant temperature of 35°C. The duration of the test can be adjusted as needed, usually from 24 hours to 1000 hours. The results of the ASTM B117 test are usually expressed in terms of the degree of corrosion on the specimen, such as corrosion area in percent or corrosion time in hours.

 

ASTM G85 is a more stringent salt spray test standard for evaluating the corrosion resistance of coatings and materials. It was also developed by ASTM and is a relatively new standard. The purpose of the ASTM G85 test is to simulate the harsher corrosion conditions in the real environment, such as high temperature, high humidity and salt spray environment. The test conditions consisted of spraying a 5% saline solution on the specimen at a constant temperature of 35°C to 50°C, and at a humidity of 95%. The duration of the test typically ranges from 24 hours to 1000 hours, depending on the desired test results. The results of ASTM G85 tests are usually expressed in terms of the degree of corrosion on the specimen, such as corrosion area in percent or corrosion time in hours.

 

In general, ASTM B117 and ASTM G85 are both standards used to evaluate the corrosion resistance of materials and coatings, but ASTM G85 is a more stringent test standard that simulates more severe corrosion conditions. The choice of which standard to use depends on the desired test results and the requirements of the application area.