Highly alloyed chromium-nickel-silicon steel with austenitic structure, used for heavily loaded kit parts requiring heat resistance up to 1150 °C (in practice up to 1100 °C), creep resistant up to 690 °C, resistance to oxidation and Various loads at high temperatures. H25N20S2 steel is the right choice for components operating in a very gaseous environment containing Nitrogen and Oxygen. Unfortunately, the quality does not show the same properties in contact with Sulfur compounds. Heat resistance at high concentrations is approx. 900°C. Lower temperatures also apply in environments or sediments where gases are reduced.