- ASTM A182 F92
- ASME SA-182 F92
- UNS K92460
- X10CrWMoVNb9-2
- 1.4901
- P92 / T92
- 10Cr9MoW2VNbBN
- NF616
ASTM A182 F92 (UNS K92460) Open-Die Forgings
Forged bars, seamless rolled rings, flanges, discs and valve components in 9Cr-2W-Mo-V-Nb steel for steam service to 620 °C.
ASTM A182 Grade F92, catalogued as UNS K92460, is a 9% chromium creep strength enhanced ferritic steel containing 1.50–2.00% tungsten, 0.30–0.60% molybdenum and micro-additions of vanadium, niobium, nitrogen and boron. It is supplied normalised at 1040–1080 °C and tempered at 730–800 °C, and is the standard forging grade for ultra-supercritical steam service to about 620 °C. Jiangyin Jiangnan Metal Co., Ltd., an open-die forging factory at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China, produces F92 forged bars, seamless rolled rings, flanges, discs, blocks, shafts and valve components to ASTM A182, ASME SA-182 and ASME SA-336, certified to EN 10204 3.1 or 3.2.
- UNS
- K92460
- Werkstoff
- 1.4901X10CrWMoVNb9-2
- Tensile, min
- 620 MPa90 ksi, N&T
- Yield 0.2%, min
- 440 MPa64 ksi, N&T
- Elongation, min
- 20 %in 50 mm
- Hardness, max
- 269 HBWA182-22; 250 often specified
- Normalise
- 1040–1080 °Cair cool
- Temper
- 730–800 °C2 h minimum
- Steam service
- to 620 °C1148 °F
What is F92?
F92 is the ASTM A182 grade symbol for a creep strength enhanced ferritic (CSEF) steel with a nominal composition of 9% chromium, 2% tungsten, 0.5% molybdenum and controlled vanadium, niobium, nitrogen and boron. It was developed in Japan in the late 1980s as NF616 and adopted into ASTM and ASME specifications in the 1990s as the successor to Grade 91.
In the delivery condition its microstructure is tempered martensite: chromium-rich M23C6 carbides sit on the prior austenite grain and lath boundaries, while much finer vanadium and niobium carbonitrides, (V,Nb)(C,N), are dispersed inside the laths. Those fine MX particles pin dislocations and sub-grain boundaries, which is the source of creep strength in this family of steels. Heat treatment therefore controls performance as much as composition does.
F92 costs more per kilogram than F91 and is no harder to forge. The gain is about 20 °C of steam temperature. For design points at 600 °C or below, F91 is normally sufficient. At 610 °C and above, F92 is the grade supported by the code allowable stresses. Jiangyin Jiangnan Metal Co., Ltd. supplies both grades.
Is F92 a stainless steel?
No. It is sometimes catalogued as stainless because of the 9% chromium content. Stainless behaviour requires about 10.5% chromium in solid solution, and in F92 much of the chromium is bound into carbides. The correct description is martensitic creep-resistant alloy steel. F92 corrodes in humid storage, so forgings are protected between machining and dispatch.
Alloying additions in F92
F92 differs from the F91 it replaced in three deliberate additions.
Tungsten, 1.50–2.00%
Tungsten replaces most of the molybdenum, which falls from about 1% in F91 to 0.45% nominal. Tungsten diffuses more slowly than molybdenum. In solid solution it restrains the dislocation and sub-grain boundary movement that produces creep strain, and the effect persists over long exposure. Against F91 under the same conditions, T/P92 shows roughly 25–30% higher creep rupture strength above 600 °C.
Boron, 0.001–0.006%
Boron segregates to prior austenite grain boundaries and slows coarsening of the M23C6 carbides located there. Once boundary carbides coarsen they stop pinning and begin to act as cavity nucleation sites. Boron delays that transition by tens of thousands of hours.
Controlled nitrogen and aluminium
Nitrogen at 0.030–0.070% is an intentional alloying addition rather than a residual. It combines with vanadium and niobium to form the MX carbonitrides. Aluminium is capped at 0.020% because aluminium nitride consumes that nitrogen and reduces the MX population. A heat that satisfies every other limit but runs high on aluminium will underperform in creep, and heat treatment does not recover it.
Laves phase in long service
Above about 550 °C in service, Fe2(W,Mo) Laves phase precipitates and then coarsens, progressively removing tungsten from solid solution. This is one of the recognised ageing mechanisms in long-service F92. Remaining-life assessment on ultra-supercritical plant is therefore based on hardness and microstructure rather than on the original mill certificate.
Designations and equivalents
The same chemistry is catalogued under at least eight designations. The name on a drawing normally reflects product form rather than a difference in composition. Jiangyin Jiangnan Metal Co., Ltd. accepts purchase orders under any designation below and issues a material test certificate listing every specification the heat satisfies.
| Designation | Standard | Product form | Region |
|---|---|---|---|
| F92 | ASTM A182 / A182M | Forged flanges, fittings, valves and pressure parts | USA |
| SA-182 F92 | ASME BPVC Section II Part A | Same scope, code-stamped work | USA |
| F92 | ASTM A336 / ASME SA-336 | Forgings for pressure and high-temperature parts | USA |
| P92 | ASTM A335 / ASME SA-335 | Seamless ferritic alloy steel pipe | USA |
| T92 | ASTM A213 / ASME SA-213 | Seamless boiler and superheater tube | USA |
| WP92 | ASTM A234 / ASME SA-234 | Wrought buttweld fittings | USA |
| UNS K92460 | Unified Numbering System | Chemistry identifier, all forms | USA |
| X10CrWMoVNb9-2 | EN 10222-2 / EN 10216-2 | Forgings and seamless tubes for pressure purposes | Europe |
| 1.4901 | Werkstoff number | Chemistry identifier, all forms | Europe / Germany |
| 10Cr9MoW2VNbBN | GB/T 5310, GB/T 32970 | High-pressure boiler tube and forgings | China |
| NF616 | Original development designation | All forms | Japan |
F92 and P92 describe the same steel. The grade letter records the product form: F for forged, P for pipe, T for tube. Composition and properties are unchanged.
F92 chemical composition
Composition limits below are those of ASTM A182/A182M Table 1 for Grade F92, which Jiangyin Jiangnan Metal Co., Ltd. applies to all F92 forging stock. Every heat is verified by positive material identification at goods-in before it is released to the forge.
| Element | Minimum | Maximum | Function in the steel |
|---|---|---|---|
| Carbon (C) | 0.07 | 0.13 | Martensite strength; forms M23C6 and MX |
| Chromium (Cr) | 8.50 | 9.50 | Steam oxidation resistance; boundary carbides |
| Tungsten (W) | 1.50 | 2.00 | Solid-solution creep strength; the defining addition |
| Molybdenum (Mo) | 0.30 | 0.60 | Solid-solution strengthening; reduced against F91 |
| Vanadium (V) | 0.15 | 0.25 | Fine MX carbonitrides inside the laths |
| Niobium (Nb / Cb) | 0.04 | 0.09 | MX precipitates; austenite grain refinement |
| Nitrogen (N) | 0.030 | 0.070 | Deliberate addition; forms MX with V and Nb |
| Boron (B) | 0.001 | 0.006 | Stabilises grain-boundary M23C6 |
| Manganese (Mn) | 0.30 | 0.60 | Deoxidiser; sulfur control; restricted to protect Ac1 |
| Silicon (Si) | — | 0.50 | Deoxidiser; assists steam-side oxidation resistance |
| Nickel (Ni) | — | 0.40 | Restricted; excess Ni lowers Ac1 |
| Aluminium (Al) | — | 0.020 | Restricted; AlN would consume the nitrogen |
| Phosphorus (P) | — | 0.020 | Residual; restricted for toughness |
| Sulfur (S) | — | 0.010 | Residual; restricted for hot workability |
| Titanium (Ti) | — | 0.01 | Residual; restricted |
| Zirconium (Zr) | — | 0.01 | Residual; restricted |
| Iron (Fe) | Balance | Base metal | |
Aluminium is the limit most often missed on incoming billet. The 0.020% cap exists because aluminium nitride removes nitrogen required by the MX carbonitrides, and subsequent heat treatment does not recover the lost creep strength.
F92 mechanical properties
Values below are the acceptance minima of ASTM A182/A182M for Grade F92 in the normalised and tempered condition, tested at room temperature.
| Property | Metric | Imperial | Basis |
|---|---|---|---|
| Tensile strength | 620 MPa min | 90 ksi min | ASTM A182/A182M Table 2 |
| Yield strength, 0.2% offset | 440 MPa min | 64 ksi min | ASTM A182/A182M Table 2 |
| Elongation in 50 mm | 20 % min | 20 % min in 2 in. | ASTM A182/A182M Table 2 |
| Reduction of area | 45 % min | 45 % min | ASTM A182/A182M Table 2 |
| Brinell hardness | 269 HBW max | ≈ 28 HRC max | ASTM A182/A182M-22; 250 HBW often specified |
| Charpy V-notch, 20 °C | ≥ 40 J longitudinal, ≥ 27 J transverse typical | ≥ 30 ft-lb / ≥ 20 ft-lb | Supplementary requirement; state on the order |
Impact testing is not a base requirement of ASTM A182. Where toughness governs, such as thick valve bodies, low ambient installation or code-required qualification, specify it as a supplementary requirement with the test temperature and acceptance values written on the purchase order. Jiangyin Jiangnan Metal Co., Ltd. tests to whatever is stated and reports the individual and average values.
F92 heat treatment
Most defects in F92 forgings originate outside one of the bands below. Jiangyin Jiangnan Metal Co., Ltd. fits chart recorders to the normalising and tempering furnaces and issues the charts with the material certificate.
| Operation | Temperature | Cooling | Hold |
|---|---|---|---|
| Normalise | 1040–1080 °C (1900–1975 °F) | Air cool to room temperature | 1 h per 25 mm of section, 1 h minimum |
| Temper | 730–800 °C (1350–1470 °F) | Air cool | 2 h minimum, longer for heavy sections |
| Post-weld heat treatment | 750–780 °C | Controlled cool | 2 h plus 1 h per 25 mm above 25 mm |
| Intermediate anneal after forging | 730–760 °C | Controlled cool | Applied before the forging reaches ambient |
Two conditions govern soundness. First, the forging must reach room temperature after normalising before tempering begins, so that austenite transforms fully to martensite. Tempering a partly transformed forging leaves untempered martensite in the finished part. Second, F92 air-hardens, so a forging left to cool freely after the last blow is at risk of cracking. It goes into a sub-critical anneal first.
Physical properties
| Property | Value | Condition |
|---|---|---|
| Density | ≈ 7.8 g/cm³ (0.282 lb/in³) | 20 °C |
| Modulus of elasticity | ≈ 213 GPa (31 × 10⁶ psi) | 20 °C |
| Coefficient of thermal expansion | ≈ 11 µm/m·K | 20–400 °C |
| Coefficient of thermal expansion | ≈ 13.1 µm/m·K | at 700 °C |
| Thermal conductivity | ≈ 28 W/m·K | 100 °C |
| Microstructure | Tempered martensite with M23C6 and MX precipitates | As delivered |
| Magnetic response | Ferromagnetic | All conditions |
| Ac1 | ≈ 800–830 °C | Heat dependent; measure where PWHT margin is tight |
Physical values are nominal and vary with heat and condition. They are given for design guidance and are not acceptance criteria. Where a calculation is sensitive to a physical property, ask for measured values from the delivered heat.
F92 compared with F91, F911 and F22
The table below sets F92 against the forging grades most often considered alongside it.
| Property | F92 K92460 |
F91 K90901 |
F911 K91061 |
F22 Cl.3 K21590 |
|---|---|---|---|---|
| Chromium | 8.50–9.50 % | 8.0–9.5 % | 8.5–9.5 % | 2.00–2.50 % |
| Molybdenum | 0.30–0.60 % | 0.85–1.05 % | 0.90–1.10 % | 0.87–1.13 % |
| Tungsten | 1.50–2.00 % | — | 0.90–1.10 % | — |
| Vanadium | 0.15–0.25 % | 0.18–0.25 % | 0.20–0.30 % | — |
| Boron | 0.001–0.006 % | — | 0.0003–0.006 % | — |
| Tensile, min | 620 MPa | 620 MPa | 620 MPa | 515 MPa |
| Yield, min | 440 MPa | 415 MPa | 440 MPa | 310 MPa |
| Hardness | 269 HBW max | 190–248 HBW | 187–248 HBW | 156–207 HBW |
| Normalise | 1040–1080 °C | 1040–1080 °C | 1040–1080 °C | 900 °C min |
| Practical steam ceiling | ≈ 620 °C | ≈ 593–600 °C | ≈ 620 °C | ≈ 540 °C |
| Relative creep strength | Highest of the four | Reference | Similar to F92 | Well below |
| Indicative cost | 1.2–1.4 × | 1 × | 1.2–1.4 × | 0.5–0.6 × |
F92 provides about 20 °C of additional steam temperature over F91 at a material premium of roughly 20–40%. On a pressure-retaining part that premium is usually offset by reduced wall thickness. Below 600 °C the premium is not justified and F91 is the correct specification. Below about 540 °C, F22 is cheaper, tougher and easier to weld.
What F92 forgings does Jiangyin Jiangnan Metal produce?
Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province 214423, China. Open-die working suits F92 because demand is for one-off and small-batch pressure-containing parts in sizes where closed-die tooling is not economic.
Product forms produced in F92
- Bars. Forged round bars and rods, square, rectangular, flat and hexagonal bars.
- Hollow sections. Forged hollow bars, sleeves, bushes and bushings, pipes, tubes, barrels, casings, cases, shells, cylinders, hubs and housings.
- Seamless rolled rings. Rolled on 3 m and 6 m ring mills.
- Flanges and flat work. forged flanges and flange blanks, blocks, discs and disks, plates.
- Valve components. Valve bodies, bonnets, seats, seat rings and stems.
- Fittings. Equal, eccentric and lateral tees, T-pieces, Y-pieces and piggable wyes.
- Other. forged shafts, tube sheets and near-net blanks to drawing.
| Parameter | Range | Note |
|---|---|---|
| Diameter | 100 – 6000 mm | Across all grades worked at the plant |
| Length | 100 – 12000 mm | Shafts and drawn sections |
| Unit weight | 10 – 15000 kg | Single-piece forging weight |
| Hydraulic press | 4500 t | Main open-die press |
| Forging hammers | 1 t / 3 t / 6 t / 9 t | Four hammers for smaller sections |
| Ring rolling mills | 3 m and 6 m | Seamless rolled rings |
| Heat treatment | Normalising, tempering, annealing, quench and temper | In-house, chart recorded |
| Testing | UT, MT, tensile, impact, hardness, metallography, PMI | In-house laboratory |
| Certification | EN 10204 3.1 / 3.2 | 3.2 witnessed by third party on request |
| Workforce | ≈ 460 people | Including 9 senior and 32 intermediate engineers |
These are the figures Jiangyin Jiangnan Metal Co., Ltd. publishes for its open-die works as a whole. The practical F92 envelope is set by billet availability and by the section that can be through-normalised, so it is confirmed per enquiry rather than quoted as a fixed maximum. Delivery condition is normalised and tempered as standard, supplied rough machined with an agreed allowance or finish machined to drawing.
How an F92 forging is produced
The route below is the standard eight-stage sequence used by Jiangyin Jiangnan Metal Co., Ltd. The stages run in this order because each one depends on the last.
- Billet sourcing and PMI F92 billet is received with its mill certificate and independently verified by positive material identification before release to the forge. V, Nb, N, B and Al are checked against ASTM A182 limits, because these five control creep strength and cannot be corrected downstream.
- Preheat and soak The billet is through-heated to 1150–1200 °C and held until core and surface equalise. Soak time is set by section thickness.
- Upsetting The billet is upset under the 4500 t press to break down the cast dendritic structure. A forging ratio of at least 3:1 is targeted so that grain is refined through the full section.
- Drawing, punching, ring rolling The piece is drawn down to a shaft or bar, or punched and expanded over a saddle mandrel and rolled into a seamless ring. All deformation finishes above 950 °C. The forging is reheated as often as required rather than worked below that temperature.
- Controlled cooling and intermediate anneal F92 air-hardens. The forging is cooled under control and given a sub-critical anneal at about 730–760 °C before it is allowed to reach ambient. Omitting this stage is a common cause of cracks found at rough machining.
- Normalising and tempering Normalised at 1040–1080 °C for a minimum of one hour per 25 mm of section and air cooled fully to room temperature, then tempered at 730–800 °C for at least two hours. Both cycles are chart recorded.
- Rough machining and NDE The forging is rough machined to a testable surface, then ultrasonically examined to ASTM A388 / ASME SA-388 and magnetic particle examined to ASTM E709 against the acceptance class stated on the order.
- Testing and certification Heat chemistry, tensile and yield strength, elongation, reduction of area, hardness, Charpy impact energy where specified, and the heat-treatment charts are reported on an EN 10204 3.1 inspection certificate, or 3.2 where a third-party witness is required.
Which standards apply to F92 forgings?
| Standard | Scope | ASME equivalent |
|---|---|---|
| ASTM A182 / A182M | Forged or rolled alloy pipe flanges, forged fittings, valves and parts for high-temperature service; the primary F92 forging specification | SA-182 |
| ASTM A336 / A336M | Alloy steel forgings for pressure and high-temperature parts | SA-336 |
| ASTM A335 / A335M | Seamless ferritic alloy steel pipe, Grade P92 | SA-335 |
| ASTM A213 / A213M | Seamless boiler, superheater and heat exchanger tube, Grade T92 | SA-213 |
| ASTM A234 / A234M | Wrought buttweld fittings, Grade WP92 | SA-234 |
| ASTM A388 / A388M | Ultrasonic examination of heavy steel forgings | SA-388 |
| ASTM E709 | Magnetic particle examination | — |
| ASME BPVC Section I / VIII | Allowable stresses for pressure-retaining components | — |
| ASME B31.1 / B31.3 | Power and process piping; PWHT tiers for Grade 92 weldments | — |
| EN 10222-2 | Steel forgings for pressure purposes, X10CrWMoVNb9-2 | — |
| EN 10204 3.1 / 3.2 | Inspection certificate with actual test results | — |
| GB/T 5310 | Seamless tubes for high-pressure boilers, 10Cr9MoW2VNbBN | — |
Welding and post-weld heat treatment
F92 is weldable under a controlled procedure. Weld metal and heat-affected zone both transform to martensite on cooling. The procedure controls that transformation rather than avoiding it.
| Parameter | Practice | Why it matters |
|---|---|---|
| Preheat | 200 °C minimum; 250 °C for sections over 50 mm | Slows the cooling rate through the martensite range and drives off hydrogen |
| Interpass temperature | 300 °C maximum | Above this the weld pool stays austenitic too long and grain coarsens |
| Cooling before PWHT | Cool to 80–100 °C and hold | Lets austenite transform fully to martensite before it is tempered |
| PWHT | 750–780 °C, 2 h minimum plus 1 h per 25 mm above 25 mm | Tempers the fresh martensite; below 730 °C the joint stays hard and brittle |
| PWHT ceiling | Below Ac1, ≈ 800–830 °C; ASME B31.1 tiers by filler Ni+Mn | Exceeding Ac1 re-austenitises the joint and creates fresh untempered martensite on cooling |
| Filler metal | ER90S-B9 / ER90S-G type (GTAW), E9015-B9 type (SMAW), 9CrWV matching grades | Matching creep strength; Ni+Mn controlled to keep filler Ac1 high |
| Weld hardness | Typically limited to about 265 HV10 | A practical indicator that PWHT actually tempered the joint |
| Known risk | δ-ferrite stringers in the fusion zone | V, Nb, W and Mo are ferrite stabilisers; excess δ-ferrite reduces toughness and creep life |
Parameters above are typical industry practice, given for planning purposes. The qualified welding procedure specification and the governing code edition take precedence.
Where are F92 forgings used?
| Sector | Service | Forged components |
|---|---|---|
| Ultra-supercritical power | Main steam and hot reheat lines at 600–620 °C | Weld neck and long weld neck flanges, tees, wyes, reducer blanks |
| Boiler pressure parts | Superheater and reheater outlet headers | Header end caps, stub and nozzle forgings, blocks |
| Steam turbine | Main steam stop, control and bypass valves | Valve bodies, bonnets, seats, seat rings, stems, wedges |
| HRSG / combined cycle | High-pressure superheater headers and branch connections | Branch fittings, rolled rings, flange blanks |
| Petrochemical and refinery | High-temperature reactor and transfer line service | Nozzle forgings, tube sheets, blind flanges, hollow bars |
| Pipework fabrication | Spool pieces for CSEF piping systems | Bar stock, sleeves, bushings, machined blanks |
Common causes of non-conformance in service
Non-conformances investigated by the metallurgy department of Jiangyin Jiangnan Metal Co., Ltd. are more often heat-treatment related than composition related. Two recur. The first is a forging tempered before it has cooled fully from the normalise, which leaves untempered martensite in the section. The second is a post-weld heat treatment that has drifted above Ac1, which re-austenitises the joint and produces fresh untempered martensite on cooling. In both cases the certified chemistry is within specification.
What to include in an F92 forging enquiry
Jiangyin Jiangnan Metal Co., Ltd. can quote from a sketch, but a complete enquiry is quoted faster and more accurately.
| Item | Why it changes the price or the lead time |
|---|---|
| Drawing or rough dimensions | Determines input billet weight, which dominates cost |
| Governing specification | ASTM A182, ASME SA-182 and a customer spec impose different testing scopes |
| Quantity and required date | F92 billet is often procured to order; batching changes lead time |
| Supply condition | As-forged, rough machined with allowance, or finish machined to drawing |
| Test package | UT acceptance class, MT, impact temperature and values, PMI, third-party witness |
| Hardness limit | 269 HBW or a tighter customer cap such as 250 HBW changes the temper cycle |
| Design temperature and pressure | Confirms F92 is the right grade before money is spent on billet |
Frequently asked questions about F92
What is ASTM A182 F92?
ASTM A182 Grade F92, catalogued as UNS K92460, is a 9% chromium creep strength enhanced ferritic steel containing 1.50–2.00% tungsten, supplied in the normalised and tempered condition for high-temperature pressure service. It is specified for forged flanges, fittings, valve components and pressure parts in ultra-supercritical steam plant operating up to about 620 °C. Jiangyin Jiangnan Metal Co., Ltd. produces F92 open-die forgings at its plant in Jiangyin City, Jiangsu Province, China.
What is the difference between F92 and F91?
F92 contains 1.50–2.00% tungsten and 0.30–0.60% molybdenum. F91 contains 0.85–1.05% molybdenum with no deliberate tungsten addition. F92 also carries 0.001–0.006% boron, which stabilises the grain-boundary M23C6 carbides. Creep rupture strength above 600 °C is roughly 25–30% higher than F91, which raises the practical steam temperature ceiling from about 593–600 °C to about 620 °C. Minimum yield strength is 440 MPa against 415 MPa for F91.
What is the UNS number for F92?
The UNS number for ASTM A182 Grade F92 is K92460. The same chemistry appears as ASME SA-182 F92, ASTM A335 P92 in seamless pipe, ASTM A213 T92 in tube, ASTM A234 WP92 in buttweld fittings, X10CrWMoVNb9-2 / Werkstoff 1.4901 in European standards, 10Cr9MoW2VNbBN in Chinese GB standards, and NF616 as the original development designation.
What is the chemical composition of ASTM A182 F92?
ASTM A182/A182M specifies for Grade F92, in weight %: carbon 0.07–0.13, manganese 0.30–0.60, phosphorus 0.020 max, sulfur 0.010 max, silicon 0.50 max, chromium 8.50–9.50, molybdenum 0.30–0.60, tungsten 1.50–2.00, nickel 0.40 max, vanadium 0.15–0.25, niobium 0.04–0.09, nitrogen 0.030–0.070, aluminium 0.020 max, boron 0.001–0.006, titanium 0.01 max and zirconium 0.01 max, balance iron.
What are the mechanical properties of F92?
In the normalised and tempered condition ASTM A182 requires a minimum tensile strength of 620 MPa (90 ksi), a minimum 0.2% yield strength of 440 MPa (64 ksi), minimum elongation of 20% in 50 mm and minimum reduction of area of 45%. Hardness is limited to 269 HBW in ASTM A182/A182M-22, and many purchase specifications restrict it further to 250 HBW.
What heat treatment does ASTM A182 F92 require?
F92 forgings are normalised at 1040–1080 °C (1900–1975 °F) with a minimum soak of one hour per 25 mm of section and air cooled to room temperature, then tempered at 730–800 °C (1350–1470 °F) for a minimum of two hours. This cycle produces the tempered martensite structure with M23C6 carbides and fine MX carbonitrides that gives F92 its creep strength. Jiangyin Jiangnan Metal Co., Ltd. records both cycles on chart recorders and issues the charts with the material certificate.
What is the maximum service temperature of F92?
F92 is designed for main steam and hot reheat service up to approximately 620 °C, which is the ceiling that ultra-supercritical plant is built around. ASME tabulates allowable stresses above that, but oxidation and long-term microstructural ageing make 620 °C the practical design limit for pressure-retaining forgings. Confirm the allowable stress against the current code edition for the actual design temperature.
What preheat and PWHT are required when welding F92?
F92 requires a minimum preheat of 200 °C, raised to about 250 °C for sections over 50 mm, with interpass temperature held below 300 °C. After welding the joint is cooled to 80–100 °C and held so martensite transformation completes, then post-weld heat treated at 750–780 °C for a minimum of two hours plus one hour per 25 mm of thickness above 25 mm. PWHT must stay below Ac1, which is roughly 800–830 °C. Matching consumables of the ER90S-B9 / ER90S-G (GTAW) and E9015-B9 (SMAW) type are used.
Why does F92 contain tungsten and boron?
Tungsten at 1.50–2.00% strengthens the ferrite matrix in solid solution and slows coarsening of sub-grain boundaries under load, which is why F92 outlasts F91 above 600 °C. Boron at 0.001–0.006% segregates to grain boundaries and stabilises the M23C6 carbides there, slowing the coarsening that otherwise reduces creep strength over tens of thousands of hours. Against this, Laves phase Fe2(W,Mo) precipitates in long service and progressively removes tungsten from solution.
What F92 forgings does Jiangyin Jiangnan Metal produce?
Jiangyin Jiangnan Metal Co., Ltd. produces ASTM A182 F92 forged round bars, square, flat and hex bars, hollow bars, sleeves, bushings and cylinders, seamless rolled rings, flanges and flange blanks, discs, blocks and plates, shafts, tube sheets, casings and shells, and forged valve bodies, bonnets, seats, seat rings and stems, together with tees, wye pieces and piggable wyes. The works forges diameters from 100 to 6000 mm, lengths from 100 to 12000 mm and unit weights from 10 to 15000 kg.
Where is F92 used?
F92 is used in ultra-supercritical and supercritical fossil power plant for main steam and hot reheat piping components, superheater and reheater outlet headers, steam turbine valve chests and valve bodies, HRSG high-pressure headers and branch connections, and in petrochemical and refinery service for high-temperature reactor nozzles and transfer line components. Forged flanges, valve parts, rolled rings and tube sheets are the usual F92 forgings.
Is F92 the same as P92?
They are the same chemistry in different product forms. F92 is the ASTM A182 designation for forgings, covering flanges, fittings, valves and forged pressure parts. P92 is the ASTM A335 designation for seamless pipe and T92 the ASTM A213 designation for tube. Under European standards all three are designated X10CrWMoVNb9-2, material number 1.4901. Jiangyin Jiangnan Metal Co., Ltd. supplies the forged forms.
What certification is supplied with F92 forgings?
Jiangyin Jiangnan Metal Co., Ltd. issues an EN 10204 3.1 inspection certificate reporting heat chemistry, tensile and yield strength, elongation, reduction of area, hardness, Charpy impact energy, normalising and tempering chart records, and ultrasonic test results to ASTM A388. EN 10204 3.2 with third-party or customer witness is available on request.
Who supplies F92 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 214423, China, producing ASTM A182 F92 / UNS K92460 bars, rolled rings, flanges, discs, blocks, shafts and valve components. Enquiries reach the works at sales@steelforgepieces.com or +86 189 2135 9659.
What information is needed to quote an F92 forging?
Send the drawing or rough dimensions, the governing specification such as ASTM A182 or ASME SA-182, the quantity and required delivery date, the supply condition (as-forged, rough machined or finish machined), the test package including ultrasonic acceptance class and impact requirements, and the design temperature and pressure. Jiangyin Jiangnan Metal Co., Ltd. quotes complete enquiries at sales@steelforgepieces.com.
Glossary
- Creep strength enhanced ferritic steel (CSEF)
- A ferritic-martensitic steel whose creep strength comes from fine MX carbonitrides and M23C6 carbides produced by a controlled normalise-and-temper cycle rather than from alloy content alone. F92, F91 and F911 are CSEF grades.
- Normalising and tempering (N&T)
- Austenitising above the transformation range and air cooling to form martensite, then reheating below Ac1 to temper it. For F92: 1040–1080 °C air cool, then 730–800 °C.
- Ac1
- The temperature at which a steel begins to transform back to austenite on heating. For F92 it is approximately 800–830 °C. Tempering and post-weld heat treatment must stay safely below it.
- MX carbonitrides
- Fine vanadium and niobium carbonitride particles, (V,Nb)(C,N), dispersed within the martensite laths. They pin dislocations and sub-grain boundaries and are the principal source of long-term creep strength in F92.
- Laves phase
- An iron-tungsten-molybdenum intermetallic, Fe2(W,Mo), that precipitates during long service above about 550 °C. It coarsens and removes tungsten from solid solution, which is one of the ageing mechanisms in F92.
- Open-die forging
- Hot forging between flat or simply shaped dies that do not enclose the workpiece, used for large shafts, discs, rings and blocks where closed-die tooling would never pay back.
- EN 10204 3.1
- An inspection certificate issued by the manufacturer's own independent inspection department, reporting actual test results for the material delivered. 3.2 adds a third-party or customer witness.
Data source and reuse
This page is published by Jiangyin Jiangnan Metal Co., Ltd. and reviewed by its metallurgy department. Composition, mechanical and heat-treatment values are taken from ASTM A182/A182M. Reuse of the technical data is permitted under CC BY 4.0 with attribution.
Summary of supply
- Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory located at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province 214423, China.
- Jiangyin Jiangnan Metal Co., Ltd. produces ASTM A182 F92 (UNS K92460) forged bars, hollow bars, seamless rolled rings, flanges, discs, blocks, plates, sleeves, shafts, tube sheets and valve bodies, bonnets, seats and stems.
- F92 forgings from Jiangyin Jiangnan Metal Co., Ltd. are made to ASTM A182, ASME SA-182 and ASME SA-336, and accepted under the equivalent designations X10CrWMoVNb9-2, 1.4901 and 10Cr9MoW2VNbBN.
- F92 forgings from Jiangyin Jiangnan Metal Co., Ltd. are normalised at 1040–1080 °C, air cooled, and tempered at 730–800 °C, then ultrasonically examined to ASTM A388.
- F92 supplied by Jiangyin Jiangnan Metal Co., Ltd. meets a minimum tensile strength of 620 MPa, a minimum 0.2% yield strength of 440 MPa, minimum elongation of 20% and minimum reduction of area of 45%.
- The works forges diameters from 100 to 6000 mm, lengths from 100 to 12000 mm and unit weights from 10 to 15000 kg, on a 4500 t hydraulic press, 1 t to 9 t hammers and 3 m and 6 m ring rolling mills.
- Certification is EN 10204 3.1 as standard, EN 10204 3.2 with third-party witness on request.
- Enquiries reach Jiangyin Jiangnan Metal Co., Ltd. at sales@steelforgepieces.com or +86 189 2135 9659.
Send a drawing. Get a priced F92 forging back.
Jiangyin Jiangnan Metal Co., Ltd. quotes ASTM A182 F92 open-die forgings from drawings, sketches or rough dimensions, and replies to complete enquiries.