Introduction
304 Austenitic stainless steel S31008 (0Cr25Ni20) is a high alloy austenitic stainless steel developed for applications which require resistance to corrosion and oxidation as well as high temperature strength. It combines good mechanical properties with excellent corr-osion resistance. The combination of its high mechanical strength, weldability, and good formability has resulted in it being used extensively in the food, beverage, chemical and pharmaceutical industries.
Chemical composition
304 stainless steel (0Cr25Ni20) is an austenitic stainless steel composed of 25% chromium, 20% nickel and 0.03% phosphorus by weight. Its other alloying elements include manganese, sulphur, silicon and/or nitrogen. The composition of 304 stainless steel makes it very ductile and easy to weld and form into various shapes.
Mechanical Properties
Austenitic stainless steel S31008 has excellent mechanical and corrosion resistant properties when exposed to thermal stress. Its tensile and yield strength are both highly increased at elevated temperatures which increases its durability in harsh environments.
The ATSM designation for the material is Type 304L. Its mechanical properties are listed in the table below:
Table: Mechanical Properties of S31008 Stainless Steel
Hardness (Brinell): 93-97
Tensile Strength (MPa): 520
Yield Strength (MPa): 270
Elongation (%) : 40
Thermal Properties
Austenitic stainless steel S31008 has good heat resistance properties and is capable of withstanding high temperatures. Its thermal properties can be listed as follows:
Table: Thermal Properties of S31008 Stainless Steel
Thermal Expansion Coefficient (in/in/°C): 10-6/°C
Maximum Temperature: 1400°C
Resistance to Corrosion
Austenitic stainless steel S31008 has excellent corrosion resistance in both acidic and oxidizing environments, as well as outstanding resistance to chloride ion stress corrosion cracking. Its oxidation resistance properties make it suitable for use in environments which have extreme exposure to air and water.
It has excellent resistance to stress corrosion cracking due to the elevated nickel content and its protective chromium oxide layer. In addition, its high chromium content gives it superior resistance to corrosion in acidic environments resulting from exposure to sulphuric and phosphoric acids.
Applications
Due to its good non-magnetic properties and ability to resist corrosion and oxidation in harsh environments, S31008 stainless steel has a wide variety of uses in industrial and commercial settings.
It can be used in environments where hazardous chemicals and reactive agents are present such as in the chemical processing, oil and gas, and nuclear fuel industries. It also finds use in the food and beverage industries due to its ability to resist corrosion in damp and wet environments.
Its formability and mechanical strength also make it suitable for other applications such as architectural, marine, and automotive components.
Conclusion
Austenitic stainless steel S31008 (0Cr25Ni20) has excellent mechanical, corrosion, and thermal properties. These properties make it suitable for extreme corrosion environments and applications where extremelhigh temperatures are involved. It can be used in industries such as chemical processing, oil and gas, food and beverage, and nuclear energy. Its formability and mechanical strength also makes it useful in other areas such as architectural, marine, and automotive applications.
