Pickling And Passivation

It has be to understood that once a stainless steel surface has been heated beyond 400°C then it will start to oxidise and exhibit heat oxides colours. Sources of heat includes; welding operation, straightening operations, thermal heat treatments such as annealing or stress relieving.

These areas are both unsightly and potential corrosion sites.

The HAZ around the area can be removed either mechanically or chemically.

Pickling is a very useful operation since it's quick and can deal with complicated shaped objects.