The picture shows a metal hob ring cover which is made of steel. It can clearly be seen from the pictures that the underside of the cover has rusted. The rust has formed due to it coming into contact with air moisture and not being kept dry, the hob that this cover has been taken from is also quite old so the rusting has had a lot of time to develop. Stainless steel could have been used instead of the steel as it will have a longer working life and wouldn’t corrode.
Prevention of the hob cover could also have been done by various techniques. There are many rust-resisting alloys that could have been used like stainless steel because this forms a passivation layer which will reduce the environmental impact on the hob cover. Galvanization of the steel could also be done and this where the steel is coated with zinc, the zinc will corrode instead of the steel and will therefore protect it. The steel can also be protected by using a coating paint, lacquer or varnish which will isolate the steel from the environment.
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