Grade 904L stainless steel is a non-stabilized austenitic stainless steel with low carbon content. This high alloy stainless steel is added with copper to improve its resistance to strong reducing acids, such as sulphuric acid. The steel is also resistant to stress corrosion cracking and crevice corrosion. Grade 904L is non-magnetic, and offers excellent formability, toughness and weldability.
Some of the major applications of grade 904L stainless steels include:
- Wiring in electrostatic precipitators
- Oil refinery components
- Seawater cooling devices
- Gas scrubbing plants
- Pulp and paper processing industries
- Acetic, phosphoric and sulphuric acid processing plants
- Grade 904L stainless steels offer good oxidation resistance. However, the structural stability of this grade collapses at high temperatures, particularly above 400°C.
- Grade 904L stainless steels show good resistance to warm seawater and chloride attack, thanks to the high amounts of nickel in its chemical composition. This grade’s copper content also increases its resistance to sulphuric acid and other reducing agents.
- Welding of grade 904L stainless steels can be performed using all conventional methods.
- Grade 904L stainless steels can be solution heat-treated at 1090 to 1175°C, following by rapid cooling. Thermal treatment is suitable for hardening these grades.
|Grade||Tensile Strength (mpa) min||Yield Strength 0.2% offset (mpa) min||Elongation (% in 50mm) min|
Thermal Expansion (µm/m/°C)
|Thermal Conductivity W/m.K||Specific Heat J/kg.K|
|7900||15 at 0-100°C||11.5 at 20°C||500 at 0-100°C|