X1CrNiMoCuN20-18-7

1.4547, also known as UNS S31254 or 254 SMO, is a high-alloy, austenitic, stainless and acid-resistant steel with high ductility.

1.4547 contains high levels of chromium (Cr), nickel (Ni), molybdenum (Mo) and nitrogen (N). The chemical composition of the steel usually contains about 20 % chromium, 18 % nickel, 6 % molybdenum and 0.18 % nitrogen, together with small amounts of other elements such as copper (Cu) and iron (Fe).

One of the most remarkable properties of 1.4547 steel is its exceptional corrosion resistance. The steel offers outstanding resistance to both general corrosion and localised corrosion, including pitting and crevice corrosion, in harsh environments containing chlorides, acids and other corrosive chemicals. This makes it suitable for use in aggressive environments such as seawater, chemical processing plants and the pulp and paper industry.

Steel 1.4547 exhibits high tensile strength and excellent mechanical properties, even at elevated temperatures. This high strength allows it to withstand mechanical loads and stresses that occur in demanding applications.

Stress corrosion cracking resistance (SCC): 1.4547 provides excellent resistance to stress corrosion cracking, which is a common form of corrosion failure in stainless steels exposed to corrosive environments and tensile stresses. This property improves the reliability and durability of the material in critical applications.

Duplex structure: Like other austenitic stainless steels, steel 1.4547 has a two-phase microstructure, consisting of both austenite and ferrite phases. This duplex structure contributes to the material's combination of high strength and corrosion resistance.

Due to its superior corrosion resistance, high strength and resistance to stress corrosion cracking, steel 1.4547 is used in a wide range of demanding applications in various industries. Common applications include offshore oil and gas platforms, chemical processing equipment, desalination plants, pulp and paper industry components and structural components in marine environments.