GB/T 4237 022Cr23Ni4MoCuN S23043 Stainless Steel Plate Supplier
GB/T 4237 022Cr23Ni4MoCuN: what it is and who uses it
022Cr23Ni4MoCuN is 2304 duplex (UNS S32304, EN 1.4362): 23% chromium, 3–5.5% nickel and little molybdenum. It gives roughly 316L-level pitting resistance (PREN 23–26) with 400 MPa minimum proof strength, which lets designers cut wall thickness on tanks and structures.
Reading the designation: ‘022’ gives the carbon level (C ≤0.030% in GB/T 4237), followed by Cr23 = about 23% chromium; Ni4 = about 4% nickel; Mo = molybdenum added; Cu = copper added; N = nitrogen added. S23043 is the unified numeric code (ISC) used in GB/T 4237-2015.
SHH STEEL produces and exports austenitic-ferritic (lean 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. 022Cr23Ni4MoCuN is part of our GB/T 4237 stainless plate range; for comparison, see our ASTM A240 Type 2304 page.
Comparison with sister grades
The table compares 022Cr23Ni4MoCuN 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 |
|---|---|---|---|---|
| 022Cr23Ni4MoCuN S23043 | C ≤ 0.030, Cr 21.50 – 24.50, Ni 3.00 – 5.50, Mo 0.05 – 0.60, N 0.05 – 0.20, Cu 0.05 – 0.60 | 22.5 | 400 | 600 |
| 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 022Cr23Ni2N S22353 | C ≤ 0.030, Cr 21.50 – 24.00, Ni 1.00 – 2.80, Mo ≤ 0.45, N 0.18 – 0.26 | 24.4 | 450 | 650 |
| GB/T 4237 03Cr22Mn5Ni2MoCuN S22294 | C ≤ 0.04, Cr 21.00 – 22.00, Ni 1.35 – 1.70, Mo 0.10 – 0.80, N 0.20 – 0.25, Mn 4.00 – 6.00 | 24.5 | 450 | 650 |
| GB/T 4237 022Cr19Ni10 S30403 | C ≤ 0.030, Cr 17.50 – 19.50, Ni 8.00 – 12.00, N ≤ 0.10 | 17.5 | 180 | 485 |
| GB/T 4237 022Cr17Ni12Mo2 S31603 | C ≤ 0.030, Cr 16.00 – 18.00, Ni 10.00 – 14.00, Mo 2.00 – 3.00, N ≤ 0.10 | 22.6 | 180 | 485 |
2304 is an alternative to 304L/316L on cost and weight, not a replacement for 2205 in seawater. Weld with ER2209 (over-alloyed in Ni) or ER2307 and control heat input; ferrite in welds should stay within the agreed range.
Heat analysis limits for 022Cr23Ni4MoCuN
| Element | 022Cr23Ni4MoCuN 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 | ≤ 2.50 | Manganese. Deoxidizer; in Mn-bearing grades it replaces nickel and keeps nitrogen in solution. |
| P | ≤ 0.040 | 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 | 21.50 – 24.50 | Chromium. Forms the passive film; the main driver of corrosion and oxidation resistance. |
| Ni | 3.00 – 5.50 | Nickel. Stabilizes austenite, improves toughness and resistance to reducing acids. |
| Mo | 0.05 – 0.60 | Molybdenum. Raises pitting and crevice resistance in chlorides (×3.3 in PREN). |
| Cu | 0.05 – 0.60 | Copper. Improves resistance to sulfuric acid and, in ferritics, general corrosion and formability. |
| N | 0.05 – 0.20 | Nitrogen. Strengthens, stabilizes austenite and adds pitting resistance (×16 in PREN). |
| PREN (Cr + 3.3Mo + 16N) | 22.5 – 26.1 (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 022Cr23Ni4MoCuN 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 | ≤ 2.50 | ±0.04 | ≤ 2.54 |
| P | ≤ 0.040 | +0.005 | ≤ 0.045 |
| S | ≤ 0.030 | +0.005 | ≤ 0.035 |
| Cr | 21.50 – 24.50 | ±0.25 | 21.25 – 24.75 |
| Ni | 3.00 – 5.50 | ±0.07 (min) / ±0.10 (max) | 2.93 – 5.60 |
| Mo | 0.05 – 0.60 | ±0.03 | 0.02 – 0.63 |
| Cu | 0.05 – 0.60 | ±0.03 (min) / ±0.05 (max) | 0.02 – 0.65 |
| N | 0.05 – 0.20 | ±0.01 (min) / ±0.02 (max) | 0.040 – 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 022Cr23Ni4MoCuN plate
| Property | 022Cr23Ni4MoCuN (Table 21) |
|---|---|
| Proof strength Rp0.2, MPa | ≥ 400 |
| Tensile strength Rm, MPa | ≥ 600 |
| Elongation A, % | ≥ 25 |
| Hardness HBW | ≤ 290 |
| Hardness HRC | ≤ 31 |
Values apply to plate in the delivery heat-treated condition, tested transversely per GB/T 228.1. Hardness is checked by one method chosen by the mill.
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 022Cr23Ni4MoCuN, not the price per tonne.
Corrosion behaviour and intergranular corrosion tests
Lean duplex grades match 304L to 316L in pitting but are far more resistant to chloride stress corrosion cracking, and they are twice as strong.
PREN of 022Cr23Ni4MoCuN from the GB/T 4237 limits: 22.5 – 26.1. 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 022Cr23Ni4MoCuN can handle, the next step up in this batch is GB/T 4237 022Cr23Ni5Mo3N S22053.
Welding and fabrication of 022Cr23Ni4MoCuN
Weld lean duplex with ER2209 or ER2307 filler. Low nickel and high nitrogen make the HAZ sensitive to excessive ferrite, so avoid very low heat input on thin plate and use N2-bearing shielding gas where possible.
Lean duplex is less prone to sigma than 2205, which gives a wider working window, but impact properties of the HAZ should still be checked on thick sections.
Cutting: we cut 022Cr23Ni4MoCuN 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.
International equivalents of 022Cr23Ni4MoCuN S23043
| Standard system | Equivalent / closest grade |
|---|---|
| China GB/T 4237-2015 | 022Cr23Ni4MoCuN (S23043) |
| ASTM A240/A240M | 2304 / S32304 |
| EN 10088-2 | X2CrNiN23-4 / 1.4362 |
| JIS G4304 (hot rolled) | — |
| Common name | 2304 |
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 2304, ASME SA240 2304. See also our ASTM A240/A240M and JIS G4305 plate lists.
What the standard covers for this grade
| 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 | 022Cr23Ni4MoCuN / S23043 |
| Steel class | Austenitic-ferritic (lean 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 – 60 mm |
| Delivery condition | 950 – 1 050 °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.
How 022Cr23Ni4MoCuN plate is heat treated
Recommended heat treatment for 022Cr23Ni4MoCuN (GB/T 4237-2015 Annex C): 950 – 1 050 °C, water quench.
Lean duplex is less sensitive to intermetallic phases, but water quenching is still the norm for plate over about 6 mm.
Where this plate goes
Where lean duplex replaces austenitic plate:
- Water and wastewater tanks and treatment plant
- Pulp and paper storage tanks
- Bridges, blast walls and structural members
- Heat exchanger and hot-water tanks
- Mining and chemical process vessels
Buyers specifying 022Cr23Ni4MoCuN for these jobs often compare it with GB/T 4237 022Cr23Ni5Mo3N S22053 and GB/T 4237 022Cr17Ni12Mo2 S31603; the comparison table on this page shows the differences.
International grade pages for the alternatives mentioned above: ASTM A240 Type 2205, ASTM A240 Type 304L, ASTM A240 Type 316L.
Other GB/T 4237 grades buyers request alongside it: GB/T 4237 022Cr21Ni3Mo2N S22153, GB/T 4237 022Cr21Mn5Ni2N S22152.
Surface finish and processing
| 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.
022Cr23Ni4MoCuN plate sizes
| Dimension | Typical supply |
|---|---|
| Thickness | 3 – 60 mm |
| 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 022Cr23Ni4MoCuN plate weighs about 78.0 kg/m²; a 1 500 × 6 000 × 10 mm plate about 702 kg.
Quality documents supplied
- 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.
Supply chain and lead time
022Cr23Ni4MoCuN is a mainstream grade at Chinese stainless mills. We supply it from our own stock and processing warehouse, and by mill order from major producers such as TISCO and Baosteel Stainless, for which we act as a sales agent. Stock plate ships in about 1–2 weeks after cutting; mill orders typically take 30–60 days depending on thickness and rolling schedule.
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.
What to put on a 022Cr23Ni4MoCuN purchase order
- Standard and edition: GB/T 4237-2015
- Grade and code: 022Cr23Ni4MoCuN (S23043); 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.
FAQ
- Is 2304 better than 316L?
- For strength and stress corrosion cracking, yes: 022Cr23Ni4MoCuN (2304) has 400 MPa minimum proof strength against 180 MPa for 316L and much better SCC resistance. Pitting resistance is similar (PREN about 23–26). 316L is easier to form and weld.
- What is the chemical composition of 022Cr23Ni4MoCuN?
- Under GB/T 4237-2015 Table 16, 022Cr23Ni4MoCuN (S23043) has C ≤ 0.030, Cr 21.50 – 24.50, Ni 3.00 – 5.50, Mo 0.05 – 0.60, N 0.05 – 0.20, Cu 0.05 – 0.60. Phosphorus is limited to ≤0.040% and sulfur to ≤0.030%.
- What is the ASTM equivalent of 022Cr23Ni4MoCuN?
- The closest equivalents of 022Cr23Ni4MoCuN (S23043) are 2304 / S32304 in ASTM, X2CrNiN23-4 / 1.4362 in EN (common name: 2304). Chemistry limits differ slightly, so dual certification depends on the actual heat.
- What are the mechanical properties of 022Cr23Ni4MoCuN plate?
- GB/T 4237-2015 Table 21 requires for 022Cr23Ni4MoCuN: proof strength Rp0.2 ≥400 MPa, tensile strength ≥600 MPa and elongation ≥25%, hardness ≤290 HBW. Values apply to plate in the delivery heat-treated condition.
- Is 022Cr23Ni4MoCuN 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 022Cr23Ni4MoCuN plate can you supply?
- Under GB/T 4237 we supply 022Cr23Ni4MoCuN hot-rolled plate in 3 – 60 mm, 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.
Conclusion
GB/T 4237 022Cr23Ni4MoCuN (S23043) is a lean duplex plate grade, known internationally as 2304. It is defined by Table 16 chemistry (C ≤ 0.030, Cr 21.50 – 24.50, Ni 3.00 – 5.50, Mo 0.05 – 0.60, N 0.05 – 0.20, Cu 0.05 – 0.60) and Table 21 properties of at least 400 MPa proof strength and 600 MPa tensile strength. Typical uses include water and wastewater tanks and treatment plant, pulp and paper storage tanks and bridges, blast walls and structural members. 2304 is an alternative to 304L/316L on cost and weight, not a replacement for 2205 in seawater.
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 022Cr23Ni4MoCuN plate from stock and by mill order, 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 022Cr23Ni2N S22353, our GB/T 4237 category and the ASTM A240 Type 2304 page. Send your sizes and quantities for a quotation.
Quality Steel Needed? Inquire for Offers
Related Products
