When it comes to salt spray testing, it must be completed with the help of a salt spray test chamber.
The salt spray test chamber evaluates the salt spray corrosion ability of materials and their protective layers, and compares the process quality of similar protective layers.
Salt spray test chamber can also evaluate the ability of certain products to resist salt spray corrosion. This product is used in parts, electronics Salt spray corrosion test of components, protective layers of metal materials and industrial products;
1. Which products require salt spray testing?
Metals and their alloys
metal covering
organic cover
anodized film
2. Covering layer
1) Covering layer type
Organic coatings, such as paint, varnish, powder coating, anti-rust oil, etc.
Metal coating, such as electroplating, chemical plating, ion plating, spray plating, hot dip plating, chemical vapor deposition, etc. Commonly used electroplating layers include zinc plating, copper plating, nickel plating, chromium plating, tin plating, brass plating, lead-tin alloy plating, etc.
2)The function of covering layer
Aesthetics For example: bright chrome plating
Protect base metal from corrosion
3. Classification of test methods for salt spray test
Neutral salt spray test (NSS)
Acetic acid salt spray test (AASS)
Copper Accelerated Acetic Salt Spray Test (CASS)
Commonly used standard types: ISO 9227:2006 Europe (including the United Kingdom)
ASTM B117-03 United States
DIN 50021:1988 Germany
(1) Neutral salt spray test NSS (Neutral Salt Spray)
Test standard selection
ISO 9227:2006 Europe (including UK)
ASTM B117-03 United States
DIN 50021:1988 Germany
The conditions of several test standards are the same, see the following content
Test Conditions
Sodium chloride solution concentration 50g/L± 5g/L
PH value is 6.5~7.2
The temperature inside the test chamber is 35 ±2°C
(USA 35＋1.1/-1.7 °C)
The salt spray settling rate is 1.5±0.5mL per 80cm² per hour
Sample preparation
The type, quantity, shape, and size of the specimen are determined according to the product standards. If there is no standard, it shall be negotiated by the relevant parties.
The sample must be cleaned using appropriate methods before testing, but the protective organic film intentionally coated on the sample should not be washed away.
For cut specimens, the cut area should be protected with paint, paraffin wax or tape.
Sample placement
The sample is placed in the salt spray box with the test surface facing up, and the salt spray is allowed to settle freely on the test surface. The test surface cannot be directly sprayed by salt spray.
The tested surface of the specimen should be at an angle of 20 degrees to the vertical direction.
Specimens can be placed on different levels in the box, but they must not come into contact with each other or the box, and droplets on the specimen must not fall on other specimens.
The sample holder is made of glass, plastic and other materials. The material for hanging the sample cannot be metal, but should be made of insulating materials such as fiber.
Test time
The test time is determined according to different product specifications. Generally speaking, it is 2/4/6/8/24 hours. If it is greater than 24 hours, it is an integer multiple of 24 hours.
Post-test sample handling
After the test, take out the sample and dry it naturally indoors for 0.5 to 1 hour, then gently rinse it with clean running water with a temperature no higher than 40 degrees Celsius to remove the remaining salt spray solution, and then blow dry immediately with a hair dryer.