Below shows an image of a piece of plate that has been left overnight outside in the rain. The plate is Carbon steel.
In the morning the plate was covered in Iron Oxide. Because the whole piece was covered in this Iron Oxide it suggests that the plate has gone through Uniform Corrosion (general corrosion). The steel plate itself has not been treated however from the original process of making it, had a scale on it which did offer some protection to it. The reason this is not important is because it has other stages involved within the manufacture. Once the plate has been rolled and welded. Its then sent for shot blasting which will remove the layer of corrosion from the plate. Once this layer has been removed it is then painted so that a barrier is formed to protect against corrosion when it is in service.
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