Materials know-how

By definition, corrosion is the destruction of metals by an electrochemical process. In a dry medium iron does not rust, yet corrosion causes an estimated HUF 50 billion of damage a year in Hungary. Local cells, protective coatings, galvanising and cathodic protection explained.

Protective coatings only protect while they remain intact. The other fundamental method of protection against corrosion is alloying, thanks to which stainless and acid-resistant steels came into being. From iron-carbon alloys to the welding and standardisation of A2 and A4 grades.

Extract from standard DIN EN ISO 3506. Steel groups and strength classes are designated by a sequence of letters and numbers consisting of 4 characters. The letters denote the general classification of the steel groups: A = austenitic steels, C = martensitic steels, F = ferritic steels.

Heat treatment is a technological operation consisting of controlled heating and heat transfer and/or cooling, by which the properties of products can be modified to suit their application. There are certain heat treatments that are used for a particular alloy family – for example for stainless and acid-resistant steels.

Structural steels. Materials such as steel are things we encounter primarily in practice, as users, so it is worth discussing some of their properties on the basis of their fields of application. Non-alloy structural steels are usually supplied in the hot-rolled or forged condition.