904L Stainless Steel Tube

904L Stainless Steel Tube is an acid resistant alloy grade with higher concentrations of nickel and molybdenum. This combination improves corrosion resistance when exposed to strong reducing acids such as sulfuric or formic acid. Furthermore, copper added to this grade further boosts its ability to withstand both oxidizing and non-oxidizing acids.

This austenitic alloy is ideal for severe corrosive environments due to its excellent pitting and crevice corrosion resistance, as well as stress corrosion cracking resistance. It has applications in oil refineries, gas scrubbers, fractional distillation plants and chemical processing areas.

Comparing to 304L, 904L has more chromium and nickel as well as trace amounts of copper. This combination makes it stronger against acid types like sulfuric and phosphoric acids than its cheaper counterpart, duplex stainless steel 2205.

904L offers superior corrosion resistance than most austenitic stainless steels, making it ideal for applications where oxidation may occur. Unfortunately, its nitric acid resistance cannot match that of molybdenum-free grades such as 310L.

This material is readily welded by traditional shop fabrication practices due to its low carbon content, which helps minimize carbide precipitation during welding and intergranular corrosion. SS 1.4539 Seamless Pipes can be bent without annealing in cold conditions; however, for maximum stress corrosion cracking resistance it should be annealed.