GB/T 4237 022Cr25Ni6Mo2N S22553 Stainless Steel Plate Supplier
What is GB/T 4237 022Cr25Ni6Mo2N (S22553) stainless steel plate?
022Cr25Ni6Mo2N is a 25Cr duplex with Mo 1.50–2.50% and N 0.10–0.20%, close to UNS S31200 (44LN type). It sits between 2205 and super duplex in chromium but carries less molybdenum, giving a PREN of about 31–34.
How to read the name: under GB/T 20878 the leading ‘022’ is the carbon code (here C ≤0.030%), then Cr25 = about 25% chromium; Ni6 = about 6% nickel; Mo2 = about 2% molybdenum; N = nitrogen added. S22553 is the unified numeric code (ISC) used in GB/T 4237-2015.
SHH STEEL produces and exports austenitic-ferritic (duplex) stainless plate from China, works as a sales agent for leading stainless mills, and runs its own processing warehouse for cutting and surface finishing. 022Cr25Ni6Mo2N is part of our GB/T 4237 stainless plate range; for comparison, see our ASTM A240 Type 2205 page.
Specification summary
| Item | GB/T 4237-2015 requirement / SHH STEEL supply |
|---|---|
| Standard | GB/T 4237-2015 Hot rolled stainless steel plate, sheet and strip (current edition, replaces GB/T 4237-2007) |
| Grade / unified code | 022Cr25Ni6Mo2N / S22553 |
| Steel class | Austenitic-ferritic (duplex) |
| Chemical composition | Table 16 (heat analysis); product analysis per GB/T 222 |
| Mechanical properties | Table 21 |
| Product forms | Hot-rolled thick plate (3.0 – 200 mm in the standard), hot-rolled wide strip and cut plate (2.0 – 25.4 mm) |
| Our usual thickness range | 3 – 80 mm (to 100 mm by mill order) |
| Delivery condition | approx. 1 050 – 1 125 °C, water quench |
| Surface | Hot rolled, heat treated, pickled (No.1 / 1D) as standard; ground or polished by agreement |
| Density | 7.8 g/cm³ |
| Certificate | EN 10204 3.1 mill certificate; 3.2 with third-party inspection on request |
Sister grades on the same standard are listed under GB/T 4237; cold-rolled sheet of the same chemistry is ordered to GB/T 3280, and all our plate lines sit in stainless steel sheets and plates.
Heat analysis limits for 022Cr25Ni6Mo2N
| Element | 022Cr25Ni6Mo2N heat analysis, % (Table 16) | Why it matters |
|---|---|---|
| C | ≤ 0.030 | Carbon. Low values protect welds from carbide precipitation; higher values add hot strength or hardenability. |
| Si | ≤ 1.00 | Silicon. Deoxidizer; in heat-resistant grades it builds a protective scale. |
| Mn | ≤ 2.00 | Manganese. Deoxidizer; in Mn-bearing grades it replaces nickel and keeps nitrogen in solution. |
| P | ≤ 0.030 | Phosphorus. Impurity, kept low for toughness and weld cracking resistance. |
| S | ≤ 0.030 | Sulfur. Impurity; low sulfur improves pitting resistance, hot workability and polishability. |
| Cr | 24.00 – 26.00 | Chromium. Forms the passive film; the main driver of corrosion and oxidation resistance. |
| Ni | 5.50 – 6.50 | Nickel. Stabilizes austenite, improves toughness and resistance to reducing acids. |
| Mo | 1.50 – 2.50 | Molybdenum. Raises pitting and crevice resistance in chlorides (×3.3 in PREN). |
| N | 0.10 – 0.20 | Nitrogen. Strengthens, stabilizes austenite and adds pitting resistance (×16 in PREN). |
| PREN (Cr + 3.3Mo + 16N) | 30.6 – 34.0 (minimum – mid-range) | Calculated from the limits above, not a requirement of GB/T 4237 |
Values are maximum unless a range is given. The mill reports the ladle (heat) analysis on the certificate; this is the figure to compare with Table 16.
Product (check) analysis tolerances
A check analysis drilled from the finished plate may differ slightly from the heat analysis. GB/T 4237 refers to GB/T 222 for the permitted deviations; the table applies them to the 022Cr25Ni6Mo2N limits. Deviations apply to one side of a range only, never to both sides in the same heat.
| Element | Heat analysis limit (%) | Permitted deviation | Product analysis limit (%) |
|---|---|---|---|
| C | ≤ 0.030 | +0.005 | ≤ 0.035 |
| Si | ≤ 1.00 | ±0.05 | ≤ 1.05 |
| Mn | ≤ 2.00 | ±0.04 | ≤ 2.04 |
| P | ≤ 0.030 | +0.005 | ≤ 0.035 |
| S | ≤ 0.030 | +0.005 | ≤ 0.035 |
| Cr | 24.00 – 26.00 | ±0.25 | 23.75 – 26.25 |
| Ni | 5.50 – 6.50 | ±0.10 | 5.40 – 6.60 |
| Mo | 1.50 – 2.50 | ±0.05 (min) / ±0.10 (max) | 1.45 – 2.60 |
| N | 0.10 – 0.20 | ±0.01 (min) / ±0.02 (max) | 0.09 – 0.22 |
Where the table says ‘by agreement’, the deviation is not tabulated for that content level and should be agreed in the contract, usually by reference to ASTM A480 Table A1.1.
Mechanical properties of 022Cr25Ni6Mo2N plate
| Property | 022Cr25Ni6Mo2N (Table 21) |
|---|---|
| Proof strength Rp0.2, MPa | ≥ 450 |
| Tensile strength Rm, MPa | ≥ 640 |
| Elongation A, % | ≥ 25 |
| Hardness HBW | ≤ 295 |
| Hardness HRC | ≤ 31 |
Duplex minimums are roughly twice those of 316L, which is why duplex vessels can be thinner.
How 022Cr25Ni6Mo2N performs in corrosive service
Duplex grades combine high pitting resistance (PREN 30–36) with strong resistance to chloride stress corrosion cracking, which is the classic failure of 304/316 in warm chloride water.
PREN of 022Cr25Ni6Mo2N from the GB/T 4237 limits: 30.6 – 34.0. PREN is a ranking tool for pitting in chlorides, not a guarantee; temperature, crevices, deposits and weld finish matter as much.
Intergranular corrosion testing is not compulsory for this grade in GB/T 4237-2015; when required, the method (GB/T 4334, ASTM A262 or A923 for duplex) and acceptance are agreed in the order.
If service is harsher than 022Cr25Ni6Mo2N can handle, the next step up in this batch is GB/T 4237 022Cr23Ni5Mo3N S22053.
Phase balance, strength and service limits
Duplex plate is about half ferrite and half austenite after solution annealing. Ferrite gives strength and resistance to stress corrosion cracking; austenite gives toughness and weldability. Mills measure the balance on each heat, and most project specifications ask for 35–65% ferrite in plate.
Two temperature limits apply to all duplex grades. Above about 250–300 °C long-term service causes 475 °C embrittlement, so ASME limits duplex to that range. At low temperature duplex has a ductile-brittle transition, so impact testing is normally specified at −40 °C or −46 °C for offshore plate.
Weight saving: with roughly double the proof strength of 316L, duplex shells and tanks can often be 30–40% thinner. That is the real cost case for 022Cr25Ni6Mo2N, not the price per tonne.
Cutting, forming and welding 022Cr25Ni6Mo2N plate
Target 35–65% ferrite in weld and HAZ. Use ER2209/E2209 filler, heat input about 0.5–2.5 kJ/mm and interpass ≤150 °C. Argon with 1–2% N2 helps keep nitrogen in root passes.
Too little heat input gives a ferritic, brittle HAZ; too much, or slow cooling, forms sigma and chi phases. Qualify the procedure with ferrite measurement, Charpy at −40 °C and ASTM A923 or G48 tests when the end user asks.
Cutting: we cut 022Cr25Ni6Mo2N by plasma (up to about 150 mm), laser (thin plate) or waterjet, and remove the heat-affected edge by machining where the drawing requires it.
022Cr25Ni6Mo2N equivalent grades: ASTM, EN, JIS
| Standard system | Equivalent / closest grade |
|---|---|
| China GB/T 4237-2015 | 022Cr25Ni6Mo2N (S22553) |
| ASTM A240/A240M | S31200 |
| EN 10088-2 | — |
| JIS G4304 (hot rolled) | — |
| Common name | 44LN-type 25Cr duplex |
Equivalent grades are close in chemistry and properties but are never identical: limits on carbon, nitrogen and residual elements differ. For dual or multiple certification the heat must meet every standard named on the order, and we confirm that from the heat chemistry before quotation.
Related pages: ASTM A240 Type 2205, ASTM A240 Type 2507, AISI 329. See also our ASTM A240/A240M and JIS G4305 plate lists.
Comparison with sister grades
The table compares 022Cr25Ni6Mo2N with the grades buyers most often weigh it against. Strength values are GB/T 4237-2015 minimums; PREN is calculated from the minimum chemistry.
| Grade (GB/T 4237) | Key chemistry, % | PREN min | Rp0.2 min, MPa | Rm min, MPa |
|---|---|---|---|---|
| 022Cr25Ni6Mo2N S22553 | C ≤ 0.030, Cr 24.00 – 26.00, Ni 5.50 – 6.50, Mo 1.50 – 2.50, N 0.10 – 0.20 | 30.6 | 450 | 640 |
| GB/T 4237 022Cr23Ni5Mo3N S22053 | C ≤ 0.030, Cr 22.00 – 23.00, Ni 4.50 – 6.50, Mo 3.00 – 3.50, N 0.14 – 0.20 | 34.1 | 450 | 655 |
| GB/T 4237 022Cr25Ni7Mo4N S25073 | C ≤ 0.030, Cr 24.00 – 26.00, Ni 6.00 – 8.00, Mo 3.00 – 5.00, N 0.24 – 0.32, Cu ≤ 0.50 | 37.7 | 550 | 795 |
| GB/T 4237 03Cr25Ni6Mo3Cu2N S25554 | C ≤ 0.04, Cr 24.00 – 27.00, Ni 4.50 – 6.50, Mo 2.90 – 3.90, N 0.10 – 0.25, Cu 1.50 – 2.50 | 35.2 | 550 | 760 |
| GB/T 4237 022Cr25Ni7Mo4WCuN S27603 | C ≤ 0.030, Cr 24.00 – 26.00, Ni 6.00 – 8.00, Mo 3.00 – 4.00, N 0.20 – 0.30, Cu 0.50 – 1.00 | 37.1 | 550 | 750 |
This is an older 25Cr duplex and supply is limited; for new designs 2205 or 2507 is usually easier to buy. Check the equivalence with your design code before substituting.
Heat treatment and delivery condition
Recommended heat treatment for 022Cr25Ni6Mo2N (GB/T 4237-2015 Annex C): approx. 1 050 – 1 125 °C, water quench.
Solution annealing sets the austenite/ferrite balance (target 40–60% ferrite). Water quench prevents sigma (700–950 °C) and 475 °C embrittlement.
Applications of 022Cr25Ni6Mo2N plate
Typical duplex applications:
- Chemical process equipment in oxidizing acids
- Pump and valve parts made from plate
- Pulp and paper equipment
- Seawater-side components at moderate temperature
Buyers specifying 022Cr25Ni6Mo2N for these jobs often compare it with GB/T 4237 022Cr23Ni5Mo3N S22053 and GB/T 4237 022Cr25Ni7Mo4WCuN S27603; the comparison table on this page shows the differences.
Other GB/T 4237 grades buyers request alongside it: GB/T 4237 022Cr22Ni5Mo3N S22293, GB/T 4237 022Cr19Ni5Mo3Si2N S21953.
Surface options and cut-to-size service
| Finish | Description | Availability for this grade |
|---|---|---|
| No.1 / 1D | Hot rolled, heat treated, pickled; the GB/T 4237 standard surface | Standard |
| Shot-blasted + pickled | Uniform matte for welded structures | On request |
| No.4 / brushed | Abrasive finish, grit 150–180 | Warehouse processing, thin plate |
| HL (hairline) | Long continuous lines, decorative | Warehouse processing, thin plate |
| 8K mirror | Polished reflective finish | Warehouse processing, limited sizes |
| 2B / BA | Cold-rolled finishes (ordered as GB/T 3280 sheet, not hot-rolled plate) | Sheet only |
Our warehouse cuts plate to size (plasma, laser, waterjet, saw), bevels weld edges, polishes and applies PVC protective film. Processed plate ships with the original mill heat number marked. Ask for cut pieces of other stainless steel products at the same time to consolidate freight.
Dimensions and plate weight
| Dimension | Typical supply |
|---|---|
| Thickness | 3 – 80 mm (to 100 mm by mill order) |
| Width | 1 000 / 1 219 / 1 250 / 1 500 / 1 800 / 2 000 mm; wider by mill order |
| Length | 2 000 / 2 438 / 3 000 / 6 000 mm or cut to size |
| Flatness | Per GB/T 4237; ≤15 mm per metre for plate up to 25 mm unless agreed tighter |
| Thickness tolerance | Per the GB/T 4237 dimensional tolerance tables (normal or higher accuracy as ordered) |
| Edge | Mill edge or cut edge |
Weight: plate mass in kg/m² = thickness (mm) × density (7.8 g/cm³). A 10 mm 022Cr25Ni6Mo2N plate weighs about 78.0 kg/m²; a 1 500 × 6 000 × 10 mm plate about 702 kg.
Inspection, tests and mill certificates
- Heat chemical analysis on every heat; product analysis by agreement
- Tensile test (Rp0.2, Rm, A) per batch
- Hardness test
- Ferrite content measurement
- ASTM A923 Method A/B/C for intermetallic phases when specified
- Charpy V-notch impact at −40 °C or −46 °C when specified
- Ultrasonic testing (NB/T 47013.3 or ASTM A578) when specified
- Positive material identification (PMI) on every plate leaving our warehouse
- Visual and dimensional inspection; third-party inspection (SGS, BV, TÜV, Intertek) at the buyer’s request
Certificates follow EN 10204 3.1 as standard. Where plate is also certified to ASME SA240 or ASTM A240, both standards are shown on one certificate.
Ordering information
- Standard and edition: GB/T 4237-2015
- Grade and code: 022Cr25Ni6Mo2N (S22553); add the equivalent if dual certification is needed
- Thickness × width × length, quantity in pieces or tonnes
- Thickness tolerance class and flatness if tighter than standard
- Surface finish and protective film
- Tests beyond the standard (IGC, UT, impact, ferrite, PMI, grain size)
- Certificate type (EN 10204 3.1 / 3.2) and inspection body
- Marking, packing (wooden cases, steel pallets) and delivery terms
Send the list to SHH STEEL and we return a quotation with mill, lead time and stock options. Other grades from the same standard can be combined in one shipment; browse GB/T 4237 plate grades.
Mill sourcing and lead time
022Cr25Ni6Mo2N is produced by a small number of Chinese mills with the melting and heat treatment capability for it. We place mill orders for it through the producers we represent and do not usually hold it in stock. Expect about 45–90 days, with minimum quantities per thickness; we can combine small quantities into one rolling where the mill allows.
Every plate is traceable to its heat number, and copies of the mill certificates stay on file for repeat orders and audits. The same mills also supply our ASTM A240, ASME SA240, JIS G4305 and AISI plate ranges, so mixed-standard orders can ship together.
Working with SHH STEEL
- Mill-direct prices with our own export documentation
- Own processing warehouse: cutting, bevelling, polishing, PVC film
- PMI and dimensional check before packing
- Mixed-grade shipments across our AISI stainless and GB/T plate ranges
- Technical answers from people who read the standard, not just the price list
SHH STEEL has exported stainless and carbon steel plate to buyers in Asia, the Middle East, Africa, Europe and the Americas.
FAQ
- What is 022Cr25Ni6Mo2N equivalent to?
- 022Cr25Ni6Mo2N (S22553) is closest to UNS S31200 (44LN type). It is a 25Cr duplex with Mo 1.50–2.50% and N 0.10–0.20% under GB/T 4237-2015, minimum proof strength 450 MPa and tensile 640 MPa.
- What is the chemical composition of 022Cr25Ni6Mo2N?
- Under GB/T 4237-2015 Table 16, 022Cr25Ni6Mo2N (S22553) has C ≤ 0.030, Cr 24.00 – 26.00, Ni 5.50 – 6.50, Mo 1.50 – 2.50, N 0.10 – 0.20. Phosphorus is limited to ≤0.030% and sulfur to ≤0.030%.
- What are the mechanical properties of 022Cr25Ni6Mo2N plate?
- GB/T 4237-2015 Table 21 requires for 022Cr25Ni6Mo2N: proof strength Rp0.2 ≥450 MPa, tensile strength ≥640 MPa and elongation ≥25%, hardness ≤295 HBW. Values apply to plate in the delivery heat-treated condition.
- Is 022Cr25Ni6Mo2N stainless steel magnetic?
- Yes, partly. Duplex plate contains about 50% ferrite, so it attracts a magnet, though less strongly than ferritic steel.
- What thickness of 022Cr25Ni6Mo2N plate can you supply?
- Under GB/T 4237 we supply 022Cr25Ni6Mo2N hot-rolled plate in 3 – 80 mm (to 100 mm by mill order), widths up to 2 000 mm (wider by mill order), cut to size in our warehouse. Thinner material is cold-rolled sheet to GB/T 3280.
- What is the PREN of 022Cr25Ni6Mo2N?
- Using PREN = Cr + 3.3Mo + 16N and the GB/T 4237-2015 limits, 022Cr25Ni6Mo2N has a PREN of about 30.6 at minimum chemistry and 34.0 at mid-range.
Conclusion
GB/T 4237 022Cr25Ni6Mo2N (S22553) is a standard duplex plate grade, known internationally as S31200 25Cr duplex. It is defined by Table 16 chemistry (C ≤ 0.030, Cr 24.00 – 26.00, Ni 5.50 – 6.50, Mo 1.50 – 2.50, N 0.10 – 0.20) and Table 21 properties of at least 450 MPa proof strength and 640 MPa tensile strength. Typical uses include chemical process equipment in oxidizing acids, pump and valve parts made from plate and pulp and paper equipment. This is an older 25Cr duplex and supply is limited; for new designs 2205 or 2507 is usually easier to buy.
Before ordering, state the standard edition, the grade name with its code, and any extra tests, so that the mill certificate matches your design documents. SHH STEEL supplies 022Cr25Ni6Mo2N plate by mill order through the producers we represent, cut to size and finished in our own warehouse, with EN 10204 3.1 certificates. For related grades see GB/T 4237 022Cr23Ni5Mo3N S22053 and GB/T 4237 022Cr25Ni7Mo4N S25073, our GB/T 4237 category and the ASTM A240 Type 2205 page. Send your sizes and quantities for a quotation.
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