Understanding the Working of Salt Spray Chamber
The Corrosion test is the most used and performed quality control test in the quality assurance lab of metal industry. This test is performed in a Salt Spray Chamber.
The Test is conducted on ferrous metals and alloys. It is also performed in the paint and coating industry to check the quality of coating which promises to deliver long-run performance for ferrous metals. The Corrosion phenomenon it may be a light topic to discuss but has a major adverse effect on ferrous metals. The salt-laden environment in which we live and the materials are exposed to often react with iron and initiate an oxidation reaction which turns ferrous ions (Fe) into ferrous oxide (Feo).
This reaction with time leads to the damaging of the product completely. The oxidation of the material also invites microbial reaction to occur and which lead to a proper damage and malfunctioning of a product. To avoid such situations, the paint industry or coating industry are increasing improving their product and the durability of their coating. This is done so that the coated layer can restrict the entry of moisture or any contaminant and lead to corrosion. However, the poor quality coating may erode and fall off exposing the surface to moisture and leading to oxidation. Therefore, the coating quality is to be tested using artificially created accelerated salt spray test.
But, before starting, it is important to understand the Working of a Salt Spray Chamber. It is vital that the test must be done the right way. A corrosion test chamber simulates the 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 which 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 of the chamber 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. 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.