904L has high nickel composition with low carbon content, copper alloy adding improve its resistance to corrosion, the “L” in 904L stands for low carbon, it is typical Super Austenitic stainless steel, equivalent grades are DIN 1.4539 and UNS N08904, 904L has better properties than other austenitic stainless steels.
904L Stainless Steel Chemical Composition (Max %):
Grade
Ni
Cr
Mo
Cu
C
Mn
Si
P
S
Fe
904L
23 – 28
19 – 23
4 -5
1 – 2
0.02
2
1
0.045
0.035
Balance
904L Stainless Steel Mechanical Properties
Grade
Tensile Strength, Min
Yeild Strength, Min
Elognation
Hardness
904L
490 Mpa
215 Mpa
35%
90 HRB Max
904L Stainless Steel Physical Properties
Grade
Density (Kg/M3)
Elastic Modulus (GPa)
Mean Co-Eff Of Thermal Expansion (Μm/M/°C)
Thermal Conductivity (W/M.K)
Specific Heat 0-100°C (J/Kg.K)
Elec Resistivity (NΩ.M)
0-100°C
0-315°C
0-538°C
At 20°C
At 500°C
904L
7900
190
15
–
–
11.5
–
500
952
904L Stainless Steel Properties
Excellent resistance to stress corrosion cracking due to the presence of high amounts of nickel content.
Pitting and crevice corrosion, intergranular corrosion resistance.
Grade 904L is less resistant to nitric acid.
Excellent formability, toughness and weldability, due to low carbon composition, it can be welded using any standard method, 904L cannot be hardened by heat treatment.
Non-magnetic, 904L is an Austenitic stainless steel, therefor 904L possesses Austenitic structure properties.
Heat Resistance, Grade 904L stainless steels offer good oxidation resistance. However, the structural stability of this grade collapses at high temperatures, particularly above 400°C.
Heat Treatment, 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.
904L Stainless Steel Equivalents
WERKSTOFF NR 1.4539
UNS N08904
BS 904S13
EN X1NiCrMoCu25-20-5
904L Stainless Steel VS 316L, VS Duplex
904L stainless steel price is expensive, due to high amount of molybdenum and nickel content, that leads to grade 904L is replaced by low cost grades, such as 316L, 317L, 2205, 6Mo and super duplex grades.
316L, A lower cost alternative, but with much lower corrosion resistance.
6Mo, A higher resistance to pitting and crevice corrosion resistance is needed, a large range of super austenitic grades is available, with selection based on intended environment.
2205, A very similar corrosion resistance to 904L, with the 2205 having higher mechanical strength and at a lower cost to 904L. (2205 not suitable for temperatures above 300°C, and not appropriate for difficult forming.)
Super duplex, Higher corrosion resistance is needed, together with a higher strength than 904L
904L Stainless Steel Pipe Standards
ASTM A 312 – seamless, welded, and heavily cold worked austenitic stainless steel pipes
ASTM B 673 – uns n08904, uns n08925, and uns n08926 welded pipe
ASTM B 677 – uns n08904, uns n08925, and uns n08926 seamless pipe and tube
904L Stainless Steel Tube Standards
ASTM A 213 – seamless ferritic and austenitic alloy-steel boiler, super heater, and heat-exchanger tubes
ASTM A 249 – welded austenitic steel boiler, super heater, heat-exchanger, and condenser tubes
ASTM A 269 – seamless and welded austenitic stainless steel tubing for general service
ASTM B 674 – uns n08904, uns n08925, and uns n08926 welded tube
ASTM B 677 – uns n08904, uns n08925, and uns n08926 seamless pipe and tube
904L Stainless Steel Applications
Because of above properties, 904L stainless steel pipe can be used in many applications, these range from utility scrubber assemblies to acid and fertilizer production equipment, pulp and paper processing, seawater cooling facilities. Used in processes containing sulfuric or phosphoric acids, 904L displays its excellent resistance to corrosion from those acids. The paper, gas, pharmaceutical and chemical industries also use 904L for its resistance and use to 400-450 degrees C. Alloy 904L tubing can be welded, machined, heat treated, annealed, hardened and cold worked for many purposes.
Petroleum and petrochemical equipment, for example: Reactor
Storage and transportation equipment of sulphuric acid, for example: heat exchanger
Sea water treatment equipment, sea water heat exchanger
Paper industry equipment, sulfuric acid, nitric acid equipment, making acid, pharmaceutical industry
