There are two main reasons why anyone would choose stainless steel over normal steel: its look and its durability. The fine finish of stainless steel usually makes for a beautiful surface, and the thin protective layer of oxide on its surface usually keeps corrosion at bay.
However, contaminants like dust, salt, grease and iron particles can ruin the two most attractive properties of stainless steel. They can cause dents and ugly marks on the sheet surface – ruining its aesthetic appeal. They can also damage the steel's protective chrome layer, something that will leave it vulnerable to corrosion.
Cleaning the steel is therefore imperative if you want to protect it from the damage that these surface contaminants can do. The following are ways that you can do this.
Cleaning the surface mechanically
Removing surface contaminants by scrubbing them off is an easy, and cheap, way of preserving the quality of your stainless steel. You can wire-brush the steel using stainless steel bristles. You can also use flapper wheels and abrasive disks to do the cleaning – especially if your stainless steel surface has heat tints.
You can also choose to remove the contaminants by blasting the steel. If you choose to blast the steel with sand, it is important to make sure that the sand is iron-free. This is because iron is an impurity that can stick onto the stainless steel surface and may therefore end up causing corrosion.
The same precaution against iron should be taken when using a wire brush, abrasive disks and flapper wheels. They should be free of iron before being used in the cleaning process. Doing so will help to prevent corrosion-triggered ugly marks and crevices on the stainless steel surface.
Cleaning the surface chemically
There are times when mechanical cleaning is not enough. This is especially so when the main impurities contaminating your stainless steel consist of fine metallic particles. In such cases, cleaning the stainless steel chemically is the best way to guarantee an impurity-free surface.
Acid pickling is one of the most common ways doing this. This is a process that usually involves using a mixture of hydrofluoric and nitric acids to get rid of carbon and other metallic impurities from steel surfaces.
Passivation is the other method that you can use. It is a gentler form of chemical cleaning. Instead of using a mixture of nitric acid and hydrofluoric acid, as acid pickling does, this method usually relies on dilute solutions of nitric acid to do the cleaning. It is effective in getting rid of iron particles. However, it is not as effective as acid pickling in that it is not effective when it comes to removing traces of iron oxide on the stainless steel surface. Contact your local metal company, such as A & C Metals - Sawing, to learn more.