Salt spray test or salt fog test is a standardized and popular corrosion test method, which is used to check corrosion resistance of materials and surface coatings, Usually, the materials to be tested are metallic and finished with a surface coating which is intended to provide a degree of corrosion protection to the underlying metal. Although we can check on stone, ceramics, and polymers.
The corrosion phenomenon may be a light topic to discuss but has a major adverse effect on ferrous metals, for this we need a salt spray chamber to check the ferrous metal life and reaction to the corrosion and initiates salt-laden condition inside, and that too in an accelerated manner.
Start with preparing the specimen. The specimen can be a fastener, or it can be thin metal plates that are coated or plated with paint. In case it is a fastener or something which is not flat in shape like bolts may be, they are hanged by tying them with a thread and then on a thin rod. This rod by which the nuts and bolts are hanged are then kept inside the chamber in the hanging position only. In case the specimen is flat like metal sheets or plates, they can be easily fixed on the specimen carrier area at a specified angle
After this, the chamber is firmly closed, and the parameters are set. The user can initiate the test by starting the salt fog spray and set the temperature, test cycle duration, etc. The working of Salt Spray Chamber depends on the operational technique used. It is easier and precise with zero human interference and controls are digitalized or HMI based.
Uses
Typical coatings that can be evaluated with this method are: