904L stainless steel pipe is manufactured in a large range of sizes including small diameter and large diameter dimensions, 904L stainless steel tube can be both welded and seamless tube complying with ASTM standards and ISO standards, ASTM A269 and A213 standard specifications for seamless tubes, and ASTM A249 standard for welded tubes.
904L stainless steel consists of chromium, nickel, molybdenum and copper contents, these elements give type 904L stainless steel excellent properties to resist corrosion in dilute sulfuric acid because of the addition of copper, 904L commonly is used in high-pressure and corrosion environments where 316L and 317L perform poorly. UNS N08904 pipes are manufactured to resist pitting, stress corrosion cracking, high strength, erosion corrosion and corrosion fatigue, and crevice corrosion, DIN 1.4539 tube is EN standard steel tube grade.
904L Stainless Steel Pipe & Tube Specifications
| Specification | ASTM A312, A213, A249, A677 |
|---|---|
| Grade | 904L Stainless Steel |
| Finishes | Annealing Pickling, Bright Annealing |
| NPS | 1/8″ – 24″ |
| Sch | Sch5 – Sch160 |
| Shapes | Round, U Bend, Coil Shape |
| Application | Heat Exchanger, Boiler, Condenser, Cooler, Heater |
904L Stainless Steel
904L has a high nickel composition with low carbon content, with copper alloy added to improve its corrosion resistance, the “L” in 904L stands for low carbon, it is typical Super Austenitic stainless steel, and 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 | Yield 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 Pipe Sizes
| Nominal Pipe Size | Outside Diameter | Nominal Wall Thickness | |||
|---|---|---|---|---|---|
| SCH5S | SCH10S | SCH40S/STD | SCH80S | ||
| 1/8 | 10.3 | — | 1.24 | 1.73 | 2.41 |
| 1/4 | 13.7 | — | 1.65 | 2.24 | 3.02 |
| 3/8 | 17.1 | — | 1.65 | 2.31 | 3.20 |
| 1/2 | 21.3 | 1.65 | 2.11 | 2.77 | 3.73 |
| 3/4 | 26.7 | 1.65 | 2.11 | 2.87 | 3.91 |
| 1 | 33.4 | 1.65 | 2.77 | 3.38 | 4.55 |
| 1 1/4 | 42.2 | 1.65 | 2.77 | 3.56 | 4.85 |
| 1 1/2 | 48.3 | 1.65 | 2.77 | 3.68 | 5.08 |
| 2 | 60.3 | 1.65 | 2.77 | 3.91 | 5.54 |
| 2 1/2 | 73.0 | 2.11 | 3.05 | 5.16 | 7.01 |
| 3 | 88.9 | 2.11 | 3.05 | 5.49 | 7.62 |
| 3 1/2 | 101.6 | 2.11 | 3.05 | 5.74 | 8.08 |
| 4 | 114.3 | 2.11 | 3.05 | 6.02 | 8.56 |
| 5 | 141.3 | 2.77 | 3.40 | 6.55 | 9.53 |
| 6 | 168.3 | 2.77 | 3.40 | 7.11 | 10.97 |
| 8 | 219.1 | 2.77 | 3.76 | 8.18 | 12.70 |
| 10 | 273.1 | 3.4 | 4.19 | 9.27 | 12.70 |
| 12 | 323.9 | 3.96 | 4.57 | 9.53 | 12.70 |
| 14 | 355.6 | 3.96 | 4.78 | 9.53 | — |
| 16 | 406.4 | 4.19 | 4.78 | 9.53 | — |
| 18 | 457.2 | 4.19 | 4.78 | 9.53 | — |
| 20 | 508.0 | 4.78 | 5.54 | 9.53 | — |
| 22 | 558.8 | 4.78 | 5.54 | 9.53 | — |
| 24 | 609.6 | 5.54 | 6.35 | 9.53 | — |
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 Austenitic stainless steel, and 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, followed 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 the high amount of molybdenum and nickel content, which leads to grade 904L being 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, and a large range of super austenitic grades is available, with selection based on the 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 is 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 the above properties, 904L stainless steel pipe can be used in many applications, ranging from utility scrubber assemblies to acid and fertilizer production equipment, pulp and paper processing, and 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, seawater heat exchanger
- Paper industry equipment, sulfuric acid, nitric acid equipment, making acid, pharmaceutical industry
- Pressure vessel
- Food Equipment
904 Stainless Steel Pipe & Tube
The carbon content of 904L is very low (max. 0.020%), and there is no precipitation of carbide under normal heat treatment and welding conditions. This eliminates the risk of intergranular corrosion which occurs after normal heat treatment and welding. Due to the high chromium-nickel-molybdenum content and the addition of copper, 904L stainless steel tubes can be passivated even in reducing environments such as sulphuric acid and formic acid. The high nickel content allows for a low corrosion rate in the active state. In the 0~98% concentration range of pure sulfuric acid, 904L can be used up to 40 ℃. In pure phosphoric acid in the concentration range of 0 to 85%. In industrial phosphoric acid produced by the wet process, impurities have a strong influence on corrosion resistance. In all kinds of phosphoric acid, 904L stainless steel tube corrosion resistance is better than ordinary stainless steel tubes. In the strong oxidizing nitric acid, compared with the high alloyed steel grades without molybdenum, the corrosion resistance is not good. In hydrochloric acid, 904L stainless steel tube use is limited to a lower concentration of 1-2%. In this concentration range. 904L stainless steel tube corrosion resistance is better than conventional stainless steel. 904L stainless steel tube has high resistance to pitting corrosion. In chloride solution, its crevice corrosion resistance is also good. 904L stainless steel tube of high nickel content, reducing the corrosion rate in the pits and crevices. Ordinary austenitic stainless steel at temperatures above 60 ℃, in a chloride-rich environment for stress corrosion may be sensitive, by increasing the nickel content of stainless steel, can reduce this sensitivity. Due to the high nickel content, the 904L stainless steel tube has good resistance to stress corrosion rupture in chloride solutions, concentrated hydroxide solutions and hydrogen sulphide-rich environments.
904L is designed for corrosive conditions in harsh environments, has a very low carbon content, high alloyed austenitic stainless steel, and better corrosion resistance than 316L and 317L, while taking into account the price and performance, cost-effective. The addition of 1.5% copper provides excellent corrosion resistance to reducing acids such as sulphuric and phosphoric acids.
904L stainless steel pipe (U.S. standard UNS N08904, China 00Cr20Ni25Mo4.5Cu) is a common super austenitic stainless steel, when the chromium-nickel austenitic stainless steel pitting corrosion resistance equivalent value (PREN = [Cr]+3.3[Mo]+16[N]) ≥ 40%, it can be called super austenitic stainless steel. Super austenitic stainless steel is mainly to solve the original high molybdenum (> 4%) chromium-nickel austenitic stainless steel pitting corrosion resistance, crevice corrosion resistance and other performance deficiencies and poor organizational thermal stability in the harsh corrosive conditions containing Cl- developed. It has better corrosion resistance than austenitic stainless steel – because of the addition of 1.5% copper, such as sulfuric acid and phosphoric acid for these reducing acids also have excellent corrosion resistance. In addition, it has low carbon properties for welding applications.