Corrosion and weathering are both major contributors to overall costs. Globally around 5 tonnes of steel are lost every second due to corrosion. Causing huge global costs and a significant influence on environmental conditions. Around 30% of this staggering €17.5 billion price tag can be prevented by basic corrosion testing. Not only the impact of corrosion on the environment is essential also it’s influence on insurance costs and installation off time’s.

Corrosion and weathering
Corrosion and weathering have both separate causes of weather influences. Where corrosion often refers to the degradation of the metal substrate or the delaminating of the paint weathering usually is about the degradation of the coating film.

Corrosion is mainly the product of humidity, an oxidizing agent and an accelerator. This accelerator can be one of many things, examples are aggressive ions like Chlorides and sulphates, but also electrical currents, are a significant influence. The many form of corrosion al have their own background and origin. Examples of corrosion forms are, uniform, stress, pitting, bimetal corrosion.

Weathering is caused by different factors, and has a milder effect on structural strength but a high effect on visual performance. A sports car that is only shiny for the first month and then loosing it’s gloss and colour due to weathering. UV lights, leaching of pigments and destabilization by temperature are only some examples. Weathering is manifested by creating visual defects on the surface. Degradation of binders and pigments are the main problem. When a binder degrades, the often smaller pigment starts to leach out. This will cause paint to loose its colour and gloss.

Types of corrosion test
When performing a corrosion test there is a choice of multiple types of test. Neutral environments to acidic acid, UV lighted or Cupper accelerated corrosion tests, and continuous or cyclic tests. In order to select the right test it is important to realize what type of corrosion or weathering you are trying to simulate. Industrial and national standards are often the biggest resource in the maze of corrosion test standards.