Steel high chrome
resistant mainly to chemical corrosion including oxidation in the atmosphere of air, natural water, water vapor, to the action of cold alkaline solutions diluted acids and salts except chlorides, sulphates and iodines and to the action of oil and fuels, oils, spirits, as well as foodstuffs.
Depending on the chromium content, they can be divided into:
- continuously with a content of 12 [%]to 14 Cr and to [%]0.45 C – the structure of these steels varies depending on the carbon content. In terms of low carbon content (less than [%]0.1), the alpha phase field extends throughout the temperature range and will have a ferritic structure. Continuously with an average carbon content (i.e. from 0.2 to 0[%].3 will have a ferrititic- austenit[°C]ic structure after heating above 950. Once cooled, the structure of these steels will contain ferrite and martenzite and are therefore called semi-ferrite. They constantly with a carbon content of [%]more than 0.3 pass after heating completely in austenite, and after cooling they will have a martensitic structure. When analysing cases of 0H13, 0H13J are classified as ferritic steels, 1H13 steel sits as semi-ferrist steels, while 2H13, 3H13, 4H13 steel saturates. These steels have good corrosion resistance in the presence of aqueous vapour and nitric acid, acetic acid, on the other hand, are not resistant to hydrochloric and sulphuric acid.
- continuously with a content of 16 [%]to 18 Cr and about[%] 0.1 C are steels with greater corrosion resistance e.g. H17,H17N2 have a slow-cooled ferritic or ferritistic- martenzistic structure. They are widely used in the food industry. These steels are resistant to molten sulfur and its vapours, diluted alkaic solutions, diluted cold organic acids, soap, and stress corrosion. They can be used at temperatures not exceeding 900 [°C].
- with a content of 18 to 28 ch[%]romium e.g. H25T has a ferritic structure. They can be used at temperatures not exceeding 1150 [°C].