The best-known property of stainless steel is its corrosion resistance. It is often used where other materials fail. Like all materials, however, stainless steel can suffer corrosion if it is not correctly specified, fabricated and used.

Two of the most common types of stainless steel corrosion are crevice and pitting.

Crevice corrosion occurs in stainless steel and other metals when the metal is covered, but immersed in a corrosive liquid such as seawater. Normally, stainless steel forms a protective oxide coating that protects it. In a small wet crevice, however, the oxygen becomes depleted and cannot restore this coating. As the affected area grows, chlorine ions (from the salt in the water), migrate into the crevice and build up a concentration. The chlorine ions make the solution acidic and corrosive, attacking the protective coating and the metal underneath.

If you work with stainless steel often you may come across different names for the same or similar grades. These grades are used for the vast majority of stainless steel applications.

There are lots of different types or grades of stainless steel, certainly more than 200. Each grade has a different composition. The composition determines the corrosion resistance and other properties such as strength. Alternative names exist for all these grades, for example in Europe 1.4301 is similar to grade 304.

The performance of stainless steel in any particular situation depends on a combination of factors, which must be understood and controlled:
Welding is commonly used to fabricate stainless steel. This is no more difficult than welding carbon steel, but it is somewhat different.

Cleanliness is very important. Clean before welding and prevent contamination during all stages of fabrication, particularly contamination from carbon steel (mild steel).Sparks from grinding carbon steel can rust when embedded into the surface of stainless steel, so stainless steels should be fabricated separately from carbon steels. And all ways remember to pickle and passivity after fabrication and welding!

If stainless steel is:
  • The correct grade and finish for application
  • accurately designed and fabricated
  • properly maintained
The results will be:
  • Easy to maintain
  • Durable and corrosion resistant
  • Strong and ductile
  • Environmentally friendly and Cost effective
  • 100% recyclable


Fax: 086 546 9097        Cell: +27 (0) 83 412 4585        Email: suitablesteel@anazi.co.za