ASTM A182 F22 and A336 F22 forgings (2.25Cr-1Mo)
GradeF22
- UNS
- K21590
- Nominal
- 2¼ Cr, 1 Mo ferritic low-alloy steel
- Specs
- ASTM A182/A182M, ASTM A336/A336M, ASME SA-182, ASME SA-336
- Classes
- Class 1 annealed. Class 3 normalised and tempered, or quenched and tempered
- Forged by
- Jiangyin Jiangnan Metal Co., Ltd., Jiangyin, Jiangsu, China
F22 is a 2.25 % chromium, 1 % molybdenum ferritic low-alloy steel, UNS K21590. It is forged into pressure-retaining components for elevated-temperature, high-pressure and hydrogen service.
Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory in Jiangyin, Jiangsu Province, China. It produces F22 to ASTM A182, ASTM A336 and the ASME SA equivalents, in Class 1 and Class 3, as seamless rolled rings, tubesheets, shells, hollow bars, discs, valve bodies, nozzles and flanges, rough or finish machined, with EN 10204 3.1 or 3.2 certification. Enquiries to sales@steelforgepieces.com or +86 189 2135 9659.
- Nominal chemistry
- 2.00–2.50 Cr, 0.87–1.13 Mo
- Class 1 tensile
- 415 MPa (60 ksi) min
- Class 3 tensile
- 515 MPa (75 ksi) min
- Class 3 yield
- 310 MPa (45 ksi) min
- Service ceiling
- about 595 °C / 1100 °F
- Density
- 7.85 g/cm³ (0.284 lb/in³)
Description and grade selection
F22 is the most widely used chrome-moly forging grade in refinery hydroprocessing and high-temperature steam service.
Chromium provides oxidation resistance at temperature. Molybdenum provides creep strength and resistance to high-temperature hydrogen attack. The combination gives a steel that holds useful strength well above the range where plain carbon steel is no longer acceptable, at a lower alloy cost than the 9 % chromium grades.
F22 replaces F11 (1.25Cr-0.5Mo) where creep strength or hydrogen resistance governs the design. Above the F22 range, F9 and F91 (9 % chromium) are used instead. For heavy-wall hydroprocessing reactors built since the 1990s, the vanadium-modified F22V is often specified in place of plain F22.
The letter F in the designation indicates a forging grade in the ASTM system. F22 steel is unrelated to the Lockheed Martin F-22 Raptor aircraft.
Designations and international equivalents
F22 appears under several designations that describe the same 2.25Cr-1Mo composition. The ASME SA numbers are the pressure vessel code versions of the ASTM specifications and are technically identical for this grade.
| Standard body | Specification | Designation |
|---|---|---|
| ASTM, USA | A182/A182M, forged fittings, flanges and valve parts | F22 Class 1, F22 Class 3 |
| ASTM, USA | A336/A336M, forgings for pressure and high-temperature parts | F22 Class 1, F22 Class 3 |
| ASME, USA | BPVC Section II Part A | SA-182 F22, SA-336 F22 |
| UNS, USA | Unified Numbering System | K21590 |
| EN, Europe | EN 10222-2 forgings, EN 10028-2 plate | 10CrMo9-10, material no. 1.7380 |
| DIN, Germany | DIN 17175, superseded | 10CrMo9-10 |
| JIS, Japan | G3203 forgings, G4109 plate | SFVAF22A, SFVAF22B, SCMV4 |
| GB / NB, China | NB/T 47008 forgings, GB/T 713 plate | 12Cr2Mo1, 12Cr2Mo1R |
| BS, UK | BS 1503, superseded | 622 Gr.31, 622 Gr.45 |
| AFNOR, France | NF A36-206, superseded | 10CD9-10 |
| Related grade | ASTM A182 F22V, ASTM A336 F22V | 2.25Cr-1Mo-0.25V, vanadium modified |
Equivalence between national standards is nominal. Chemistry windows, heat treatment rules and test requirements differ between them. Name one governing specification and edition on the purchase order and treat the others as cross-references.
Chemical composition
A182 and A336 use the same alloy window for chromium and molybdenum. They differ on residuals. A336, written for pressure vessel and high-temperature forgings, holds phosphorus and sulphur to half the A182 limit.
| Element | ASTM A182 F22 / SA-182 F22 | ASTM A336 F22 / SA-336 F22 |
|---|---|---|
| Carbon, C | 0.05 – 0.15 | 0.05 – 0.15 |
| Manganese, Mn | 0.30 – 0.60 | 0.30 – 0.60 |
| Phosphorus, P | 0.040 max | 0.025 max |
| Sulphur, S | 0.040 max | 0.025 max |
| Silicon, Si | 0.50 max | 0.50 max |
| Chromium, Cr | 2.00 – 2.50 | 2.00 – 2.50 |
| Molybdenum, Mo | 0.87 – 1.13 | 0.87 – 1.13 |
| Iron, Fe | Balance, approximately 95.1 – 96.8 | |
Residual elements are not limited by the base specification. They matter for heavy-wall hydrogen service, where tin, antimony and arsenic drive temper embrittlement. Reactor and exchanger orders normally carry supplementary limits on these elements. See temper embrittlement.
Mechanical properties, Class 1 and Class 3
Class 1 and Class 3 are the same steel supplied in different heat treated conditions. Acceptance criteria differ, so the class must be stated on the enquiry.
| Specification and class | Tensile strength | Yield strength, min | Elongation in 50 mm, min | Reduction of area, min | Hardness |
|---|---|---|---|---|---|
| A182 F22 Class 1 | 415 MPa (60 ksi) min | 205 MPa (30 ksi) | 20 % | 35 % | 170 HBW max |
| A182 F22 Class 3 | 515 MPa (75 ksi) min | 310 MPa (45 ksi) | 20 % | 30 % | 156 – 207 HBW |
| A336 F22 Class 1 | 415 – 585 MPa (60 – 85 ksi) | 205 MPa (30 ksi) | 20 % | 35 % | by agreement |
| A336 F22 Class 3 | 515 – 690 MPa (75 – 100 ksi) | 310 MPa (45 ksi) | 18 % | 40 % | by agreement |
Values above are the acceptance criteria of the referenced specifications, published for selection and enquiry purposes. Contractual values are those in the edition named on the purchase order and those recorded on the EN 10204 certificate issued with the forging. A336 sets an upper tensile limit as well as a lower one. A182 sets a minimum only.
Elevated temperature and long term behaviour
Above roughly 450 °C design is governed by creep rather than yield. Allowable stresses should be taken from ASME BPVC Section II Part D, Table 1A, or the relevant design code. An indicative 100 000 hour rupture strength for 2.25Cr-1Mo at 600 °C (1110 °F) is of the order of 38 MPa (5 500 psi).
For sour service, hardness capped at 22 HRC satisfies NACE MR0175 / ISO 15156 for F22. This requirement must be stated at enquiry stage so that it is built into the heat treatment cycle. A336 requires Charpy V-notch testing, normally at a temperature no warmer than −18 °C (0 °F) unless the order specifies otherwise.
Physical properties
Typical values for 2.25Cr-1Mo steel at room temperature unless stated. These are design guidance figures and are not acceptance requirements of A182 or A336.
| Property | Metric | Imperial |
|---|---|---|
| Density | 7.85 g/cm³ | 0.284 lb/in³ |
| Modulus of elasticity | 207 GPa | 30 000 ksi |
| Poisson's ratio | 0.27 – 0.30 | 0.27 – 0.30 |
| Thermal conductivity | about 37 W/(m·K) | about 257 BTU·in/(h·ft²·°F) |
| Mean coefficient of thermal expansion, 20 – 400 °C | about 12.9 × 10⁻⁶ /K | about 7.2 × 10⁻⁶ /°F |
| Specific heat capacity | about 460 J/(kg·K) | about 0.11 BTU/(lb·°F) |
| Magnetic response | Ferromagnetic, ferritic structure | |
Heat treatment and delivery condition
Class is defined by the heat treatment route and is therefore fixed at the forging stage.
| Class | Route | Notes |
|---|---|---|
| Class 1 | Full anneal | Softest condition and best machinability. Standard base metal for weld overlay cladding and for parts that will see heavy subsequent welding. |
| Class 3 | Normalise and temper, or liquid quench and temper | Tempering at 675 °C (1250 °F) minimum. Quench and temper is preferred for heavy sections where through thickness properties must be demonstrated. |
Indicative Class 3 cycle, subject to confirmation against section size and the governing procedure: austenitise at 900 to 950 °C and hold for section thickness, then air cool or liquid quench; temper at 675 to 730 °C for a minimum of one hour per 25 mm, then cool in still air. Heavy forgings normally receive a preliminary grain refining treatment before the final cycle.
Welding and post-weld heat treatment
F22 is air hardening. Without preheat the heat affected zone forms untempered martensite. Preheat and post-weld heat treatment are mandatory on pressure retaining welds.
| Parameter | Value |
|---|---|
| Preheat | 200 to 300 °C (390 to 570 °F), increasing with thickness and restraint |
| Interpass temperature | 350 °C maximum, typical |
| SMAW consumable | AWS E9018-B3 |
| GTAW and GMAW consumable | AWS ER90S-B3 |
| SAW consumable | EB3 wire and flux combination |
| PWHT | 690 to 720 °C (1275 to 1325 °F), normally one hour per 25 mm of thickness |
| PWHT limit | Must remain below the parent metal tempering temperature |
| Hydrogen control | Low hydrogen consumables, correct baking, hydrogen bake-out after welding on thick sections |
Temper embrittlement and step cooling
Long exposure between 370 °C and 560 °C raises the ductile-to-brittle transition temperature of 2.25Cr-1Mo. Toughness at start-up temperature after several years of service can therefore be substantially lower than at delivery. Hydroprocessing specifications control this with chemistry limits beyond the base ASTM requirement.
| Factor | Formula | Typical limit |
|---|---|---|
| Watanabe J-factor, base metal | J = (Si + Mn) × (P + Sn) × 10 000, elements in weight percent | 100 max, sometimes 180 for less critical duty |
| Bruscato X-bar, weld metal | X̄ = (10P + 5Sb + 4Sn + As) / 100, elements in ppm | 15 ppm max |
| Step cooling | Simulated long term ageing cycle, Charpy tested before and after | To API RP 934-A for heavy wall reactors |
Step cooling, J-factor caps and controlled residual melting affect the steelmaking route and the price. They cannot be applied to a forging after manufacture. These requirements should be stated at enquiry stage.
Applications
| Industry | Components |
|---|---|
| Refinery hydroprocessing | Hydrocracker and hydrotreater reactor shells, heads, nozzles and flanges, where resistance to high-temperature hydrogen attack to the API 941 Nelson curves governs selection |
| Power generation | Steam headers, main steam and hot reheat piping components, turbine casing parts, boiler forgings in the superheat range |
| Heat exchangers | Fixed, stationary and floating tubesheets, channel covers, girth flanges, shell sections, frequently weld overlay clad |
| Pressure vessels | Shell rings, nozzle necks, self-reinforced nozzles and closure forgings to ASME VIII Division 1 and Division 2 |
| Valves | Bodies, bonnets, closures and seat rings for high-temperature steam and hydrogen lines, to ASME B16.34 |
| Petrochemical and fertiliser | Ammonia and methanol synthesis loop components, reformer and coal gasification equipment |
Forged shapes supplied in F22
All items are open-die forged or ring rolled to customer drawing, in Class 1 or Class 3, with machining allowance agreed at order stage.
| Family | Items |
|---|---|
| Rings | Seamless rolled rings, profiled rings, ring segments |
| Hollow sections | Sleeves, bushes and bushings, cylinders, shells, casings, cases, barrels, hollow bars, pipe and tube blanks |
| Solid sections | Round bars, blocks, blanks, shafts, hubs, housings |
| Plate type forgings | Discs and disks, tubesheets, tube sheets and tube plates, blind and cover plates |
| Flanges and nozzles | Girth flanges, channel covers, cover flanges, long welding neck flanges, nozzle necks, self-reinforced FVC type nozzles |
| Valve components | Valve bodies and body blocks, bonnets, stems, closures, seat rings |
| Heat exchanger parts | Front head and rear head components, fixed, stationary and floating tubesheets |
| Clad and overlaid | Weld overlay in 309L or 347 stainless, Alloy 625 or Alloy 825, strip or wire deposited, PWHT and ultrasonically bond tested |
Manufacturing and inspection
Jiangyin Jiangnan Metal Co., Ltd. forges to drawing from customer approved steelmaking routes, including electric arc melting with ladle refining and vacuum degassing, and electroslag remelting where the specification requires it. Heat treatment is carried out in computer charted furnaces with multi-point thermocouples, with a quench tank available for liquid quench and temper. Parts are supplied as forged, rough machined, proof machined or finish machined, including vertical turning and deep hole drilling.
| Scope | Method or standard |
|---|---|
| Chemical analysis | Heat analysis and product analysis. Positive material identification on request |
| Tension testing | ASTM A370 |
| Impact testing | Charpy V-notch to ASTM A370, test temperature per order |
| Hardness | Brinell survey, with 22 HRC cap available for NACE MR0175 |
| Ultrasonic examination | ASTM A388/A388M, acceptance class per order. Bore surface examination available on hollow forgings |
| Magnetic particle | ASTM E709 or ASTM A275 |
| Liquid penetrant | ASTM E165 |
| Supplementary | Step cooling, J-factor control, through thickness testing, hydrogen bake-out, grain size and macro examination |
| Documentation | EN 10204 3.1 as standard. 3.2 with Lloyd's Register, Bureau Veritas, TÜV, SGS or the customer's own inspector |
Data required for an F22 enquiry
Enquiries containing the following can normally be quoted within one working day. Send to sales@steelforgepieces.com.
- Specification, grade and class. For example ASTM A336 F22 Class 3, or ASME SA-182 F22 Class 1, with the edition year if the project fixes one.
- Shape and dimensions. A drawing is preferred. Otherwise outside diameter, inside diameter, length or thickness, and the machining allowance required.
- Quantity and delivery condition: as forged, rough machined, proof machined or finish machined.
- Supplementary requirements: Charpy test temperature, ultrasonic acceptance class, hardness cap for NACE MR0175, step cooling, J-factor limit, cladding material and thickness.
- Certification: EN 10204 3.1 or 3.2, and the inspection body if 3.2.
- Destination port and required delivery date.
Frequently asked questions about F22
What is ASTM A182 F22 steel?
ASTM A182 Grade F22 is a forged 2.25 % chromium, 1 % molybdenum ferritic low-alloy steel, UNS K21590. It is used for pressure-retaining forgings such as flanges, fittings, valve bodies and nozzles in elevated-temperature and hydrogen service. The ASME equivalent is SA-182 F22. Jiangyin Jiangnan Metal Co., Ltd. forges the grade in Class 1 and Class 3.
What is the difference between F22 Class 1 and F22 Class 3?
Class 1 is supplied annealed. Minimum tensile strength is 415 MPa (60 ksi) and hardness is limited to about 170 HBW. Class 3 is normalised and tempered, or quenched and tempered, with tempering at 675 °C (1250 °F) minimum. Minimum tensile strength is 515 MPa (75 ksi) and minimum yield strength is 310 MPa (45 ksi). Class 3 is standard for piping and pressure parts. Class 1 is commonly specified as the base metal for weld overlay cladding.
What is the difference between ASTM A182 F22 and ASTM A336 F22?
A182 covers forged fittings, flanges and valve parts for piping. A336 covers alloy steel forgings for boilers, pressure vessels and high-temperature parts, and is normally used for heavy sections such as tubesheets, shells and reactor components. A336 limits phosphorus and sulphur to 0.025 % maximum each and requires Charpy V-notch impact testing. A182 permits 0.040 % maximum.
What is the maximum service temperature of F22 steel?
F22 is normally specified for continuous service up to about 550 to 595 °C (1020 to 1100 °F). Creep governs design above roughly 450 °C. Allowable stresses must be taken from ASME BPVC Section II Part D or the applicable design code, not from room-temperature strength.
What are the European and Chinese equivalents of F22?
The European equivalent is 10CrMo9-10, material number 1.7380, to EN 10222-2 and EN 10028-2. The Chinese equivalent is 12Cr2Mo1, or 12Cr2Mo1R for plate, to NB/T 47008 and GB/T 713. Japanese equivalents are SFVAF22A and SFVAF22B to JIS G3203 and SCMV4 to JIS G4109. Equivalence is nominal. The purchase order should name one governing specification.
Does F22 require post-weld heat treatment?
Yes. F22 is air hardening. Welds are preheated to 200 to 300 °C and given post-weld heat treatment at about 690 to 720 °C (1275 to 1325 °F), normally one hour per 25 mm of thickness. PWHT temperature must remain below the tempering temperature applied to the parent forging, otherwise the certified mechanical properties are lost.
What is the J-factor and step-cooling test for F22 forgings?
Temper embrittlement raises the ductile-to-brittle transition temperature of 2.25Cr-1Mo after long exposure between 370 °C and 560 °C. It is controlled by limiting the Watanabe J-factor, J = (Si + Mn) × (P + Sn) × 10 000, normally to 100 maximum, and the Bruscato X-bar of weld metal to 15 ppm maximum. Heavy-wall hydroprocessing reactor forgings are also step cooled and Charpy tested before and after, to API RP 934-A.
What is F22V and how does it differ from F22?
F22V is the vanadium-modified version, nominally 2.25Cr-1Mo-0.25V, covered by ASTM A182 F22V and A336 F22V. Vanadium raises creep strength and resistance to high-temperature hydrogen attack, which permits thinner walls in modern hydrocracker and hydrotreater reactors. Plain F22 remains standard for general piping, exchanger and pressure vessel forgings.
Is the steel grade F22 related to the F-22 fighter aircraft?
No. Grade F22 on this page is a 2.25Cr-1Mo forged low-alloy steel designated by ASTM A182 and ASTM A336. It is unrelated to the Lockheed Martin F-22 Raptor aircraft. The letter F in the steel designation indicates a forging grade in the ASTM system.
Which forged shapes can be supplied in F22?
Jiangyin Jiangnan Metal Co., Ltd. supplies grade F22 as seamless rolled rings, sleeves, bushes, shells, casings, barrels, cylinders, hollow bars, round bars, blocks, discs, tubesheets and tube plates, valve bodies, bonnets, stems, closures and seat rings, girth flanges, channel covers, cover flanges, long welding neck flanges, self-reinforced FVC-type nozzles, shafts, hubs and housings.
Can F22 tubesheets be supplied with weld overlay cladding?
Yes. F22 is a common base metal for clad tubesheets and channel covers. Overlays in 309L or 347 stainless steel, Alloy 625 or Alloy 825 are applied by strip or wire deposition, then given PWHT and ultrasonic bond testing to ASME Section V. Stationary, floating, front-head and rear-head tubesheets can all be supplied clad.
What certification is supplied with F22 forgings?
Forgings are supplied with an EN 10204 3.1 mill certificate, or 3.2 with third-party witness by Lloyd's Register, Bureau Veritas, TÜV, SGS or the customer's own inspector. The certificate records heat and product chemical analysis, heat treatment charts, tensile and Charpy V-notch results, hardness, ultrasonic and magnetic particle examination and dimensional data.
Who manufactures ASTM A182 F22 and A336 F22 open-die forgings in China?
Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China. It produces grade F22 rings, tubesheets, shells, hollow bars, valve bodies and flanges to ASTM A182, ASTM A336 and the ASME SA equivalents. Contact: sales@steelforgepieces.com, +86-189-2135-9659.
Request a quotation for F22 forgings
Send a drawing, or the specification, class, dimensions and quantity.
Jiangyin Jiangnan Metal Co., Ltd.
No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China
Phone and WhatsApp: +86 189 2135 9659
Email: sales@steelforgepieces.com
Related alloy steel grades
Document reference: F22 material datasheet, Jiangyin Jiangnan Metal Co., Ltd. Revision date . Web version at https://www.steelforgepieces.com/Alloy-Steel/F22.html. Plain text version at F22.md.
Property values are taken from ASTM A182/A182M and ASTM A336/A336M and are published for material selection. Contractual values for any order are those recorded on the EN 10204 certificate issued with the forging.