Rust is an inorganic polymer including iron and both oxygen and water. Rust cannot form without both oxygen and water present. Another problem which must be addresses is - the "seed". It is a known fact of chemical reaction that chemically pure iron will not rust in the presence of chemically pure oxygen and chemically pure water. Rust requires a nucleus ("seed") to form. But once the seed has formed initial rust, the process is self-regenerating
In some cases we are our own worst enemies. We create the seed by improper cleaning when we leave residual amounts of a cleaner which should have been removed through final rinsing. In some unavoidable cases, the metallurgist has selected an alloy for certain required performance criteria, but that combination has created the possibility of "galvanic" action occurring. For galvanic action to occur, we need two dissimilar materials and a source of electrolyte such as salty water. Galvanic action creates an electrical current causing a change in the state of the iron and as a result, rust is formed.
Have you seen a chrome-plate
metal flaking and wondered why ? It is because rust is a polymer, the chain
of rust will grow under a layer of plating until plating eventually comes loose.
This is attributed to a "seed" or a single flawed area in a plated metal. This
is why one must carefully watch for small flaws. The best preventive measure
is to make absolutely sure that the product if fully cleaned. Careful measures
should be taken to assure the cleaner is completely rinsed off.
Other common causes of corrosion
- Various airborne contaminants
- Manual handling
- Uncontrolled manufacturing and storage areas.
Appearance of corrosion leads to
- Poor Quality
- Reduced Product Life
- Product Failure
- Customer Dissatisfaction
- Disposal Problems
- Additional Costs