GB/T 4237 06Cr18Ni12Mo2Cu2 S31688 Stainless Steel Plate Supplier
GB/T 4237 06Cr18Ni12Mo2Cu2: what it is and who uses it
06Cr18Ni12Mo2Cu2 is the Japanese SUS316J1 type: copper 1.00–2.50% added to a 316 base with Mo 1.20–2.75%. Copper improves resistance to sulfuric acid, so the grade sits between 316 and 904L for reducing acids.
How to read the name: under GB/T 20878 the leading ’06’ is the carbon code (here C ≤0.08%), then Cr18 = about 18% chromium; Ni12 = about 12% nickel; Mo2 = about 2% molybdenum; Cu2 = about 2% copper. S31688 is the unified numeric code (ISC) used in GB/T 4237-2015. Older drawings and Chinese buyers may still write the pre-2007 name 0Cr18Ni12Mo2Cu2.
SHH STEEL produces and exports austenitic stainless plate from China, works as a sales agent for leading stainless mills, and runs its own processing warehouse for cutting and surface finishing. 06Cr18Ni12Mo2Cu2 is part of our GB/T 4237 stainless plate range; for comparison, see our AISI 316 page.
Heat analysis limits for 06Cr18Ni12Mo2Cu2
| Element | 06Cr18Ni12Mo2Cu2 heat analysis, % (Table 15) | Why it matters |
|---|---|---|
| C | ≤ 0.08 | 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 | ≤ 0.045 | 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 | 17.00 – 19.00 | Chromium. Forms the passive film; the main driver of corrosion and oxidation resistance. |
| Ni | 10.00 – 14.00 | Nickel. Stabilizes austenite, improves toughness and resistance to reducing acids. |
| Mo | 1.20 – 2.75 | Molybdenum. Raises pitting and crevice resistance in chlorides (×3.3 in PREN). |
| Cu | 1.00 – 2.50 | Copper. Improves resistance to sulfuric acid and, in ferritics, general corrosion and formability. |
| PREN (Cr + 3.3Mo + 16N) | 21.0 – 24.5 (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 15.
Product analysis vs heat analysis
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 06Cr18Ni12Mo2Cu2 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 | ≤ 0.08 | ±0.01 | ≤ 0.09 |
| Si | ≤ 1.00 | ±0.05 | ≤ 1.05 |
| Mn | ≤ 2.00 | ±0.04 | ≤ 2.04 |
| P | ≤ 0.045 | +0.010 | ≤ 0.055 |
| S | ≤ 0.030 | +0.005 | ≤ 0.035 |
| Cr | 17.00 – 19.00 | ±0.20 | 16.80 – 19.20 |
| Ni | 10.00 – 14.00 | ±0.10 (min) / ±0.15 (max) | 9.90 – 14.15 |
| Mo | 1.20 – 2.75 | ±0.05 (min) / ±0.10 (max) | 1.15 – 2.85 |
| Cu | 1.00 – 2.50 | ±0.05 (min) / ±0.10 (max) | 0.95 – 2.60 |
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 at room temperature
| Property | 06Cr18Ni12Mo2Cu2 (Table 20) |
|---|---|
| Proof strength Rp0.2, MPa | ≥ 205 |
| Tensile strength Rm, MPa | ≥ 520 |
| Elongation A, % | ≥ 40 |
| Hardness HBW | ≤ 187 |
| Hardness HRB | ≤ 90 |
| Hardness HV | ≤ 200 |
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.
Corrosion resistance and PREN of 06Cr18Ni12Mo2Cu2
Molybdenum raises resistance to chlorides, sulfurous media and reducing acids. The low-carbon and nitrogen variants keep that resistance across welds.
PREN of 06Cr18Ni12Mo2Cu2 from the GB/T 4237 limits: 21.0 – 24.5. PREN is a ranking tool for pitting in chlorides, not a guarantee; temperature, crevices, deposits and weld finish matter as much.
Intergranular corrosion: GB/T 4237-2015 Table 30 lists this grade for the copper–copper sulfate–sulfuric acid test (GB/T 4334 Method E) in the solution-treated condition. When the order calls for it, bent specimens must show no intergranular cracks.
If service is harsher than 06Cr18Ni12Mo2Cu2 can handle, the next step up in this batch is GB/T 4237 015Cr21Ni26Mo5Cu2 S31782.
06Cr18Ni12Mo2Cu2 equivalent grades: ASTM, EN, JIS
| Standard system | Equivalent / closest grade |
|---|---|
| China GB/T 4237-2015 | 06Cr18Ni12Mo2Cu2 (S31688) |
| Former Chinese name | 0Cr18Ni12Mo2Cu2 |
| ASTM A240/A240M | — (no A240 type) |
| EN 10088-2 | — |
| JIS G4304 (hot rolled) | SUS316J1 |
| Common name | 316J1 |
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: AISI 316, JIS G4305 SUS316. 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 | 06Cr18Ni12Mo2Cu2 / S31688 |
| Steel class | Austenitic |
| Chemical composition | Table 15 (heat analysis); product analysis per GB/T 222 |
| Mechanical properties | Table 20 |
| 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 – 120 mm (to 150 mm by mill order) |
| Delivery condition | 1 010 – 1 150 °C, rapid cooling |
| Surface | Hot rolled, heat treated, pickled (No.1 / 1D) as standard; ground or polished by agreement |
| Density | 8.0 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.
06Cr18Ni12Mo2Cu2 compared with related grades
The table compares 06Cr18Ni12Mo2Cu2 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 |
|---|---|---|---|---|
| 06Cr18Ni12Mo2Cu2 S31688 | C ≤ 0.08, Cr 17.00 – 19.00, Ni 10.00 – 14.00, Mo 1.20 – 2.75, Cu 1.00 – 2.50 | 21.0 | 205 | 520 |
| GB/T 4237 06Cr17Ni12Mo2 S31608 | C ≤ 0.08, Cr 16.00 – 18.00, Ni 10.00 – 14.00, Mo 2.00 – 3.00, N ≤ 0.10 | 22.6 | 205 | 515 |
| GB/T 4237 015Cr21Ni26Mo5Cu2 S31782 | C ≤ 0.020, Cr 19.00 – 23.00, Ni 23.00 – 28.00, Mo 4.00 – 5.00, N ≤ 0.10, Cu 1.00 – 2.00 | 32.2 | 220 | 490 |
| 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 |
Molybdenum can be as low as 1.20%, so pitting resistance in chlorides may be below 316. Choose it for sulfuric acid, not for seawater. It is a mill-order grade.
Fabrication guidance
Use ER316L/E316L filler, or ER317L when the weld must not be the weak point in chloride service. A small ferrite number (FN 3–10) in the weld metal prevents hot cracking.
Interpass ≤150 °C, no preheat, clean back purge with argon for root passes. Pickle and passivate after welding: heat tint lowers pitting resistance more in Mo grades than the weld itself.
Cutting: we cut 06Cr18Ni12Mo2Cu2 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.
Annealing / solution treatment
Recommended heat treatment for 06Cr18Ni12Mo2Cu2 (GB/T 4237-2015 Annex C): 1 010 – 1 150 °C, rapid cooling.
Cool rapidly through 850–450 °C after annealing; slow cooling of thick Mo-bearing plate risks carbide and sigma precipitation.
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.
Where this plate goes
Where buyers specify it:
- Sulfuric acid handling equipment at low concentration
- Chemical plant parts in reducing media
- Pickling line components
- Fertilizer plant parts
Buyers specifying 06Cr18Ni12Mo2Cu2 for these jobs often compare it with GB/T 4237 06Cr17Ni12Mo2 S31608 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 316, ASTM A240 Type 904L, ASTM A240 Type 316L.
Other GB/T 4237 grades buyers request alongside it: GB/T 4237 07Cr17Ni12Mo2 S31609, GB/T 4237 06Cr17Ni12Mo2N S31658.
Dimensions and plate weight
| Dimension | Typical supply |
|---|---|
| Thickness | 3 – 120 mm (to 150 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 (8.0 g/cm³). A 10 mm 06Cr18Ni12Mo2Cu2 plate weighs about 80.0 kg/m²; a 1 500 × 6 000 × 10 mm plate about 720 kg.
Quality documents supplied
- Heat chemical analysis on every heat; product analysis by agreement
- Tensile test (Rp0.2, Rm, A) per batch
- Hardness test
- Intergranular corrosion test, GB/T 4334 Method E (Table 30)
- 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
06Cr18Ni12Mo2Cu2 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.
What to put on a 06Cr18Ni12Mo2Cu2 purchase order
- Standard and edition: GB/T 4237-2015
- Grade and code: 06Cr18Ni12Mo2Cu2 (S31688); 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.
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 06Cr18Ni12Mo2Cu2 used for?
- 06Cr18Ni12Mo2Cu2 (S31688, SUS316J1 type) is used where 316 meets dilute sulfuric acid or other reducing media. Copper 1.00–2.50% improves resistance there. GB/T 4237-2015 requires 205 MPa proof, 520 MPa tensile, 40% elongation.
- What is the chemical composition of 06Cr18Ni12Mo2Cu2?
- Under GB/T 4237-2015 Table 15, 06Cr18Ni12Mo2Cu2 (S31688) has C ≤ 0.08, Cr 17.00 – 19.00, Ni 10.00 – 14.00, Mo 1.20 – 2.75, Cu 1.00 – 2.50. Phosphorus is limited to ≤0.045% and sulfur to ≤0.030%.
- What is the ASTM equivalent of 06Cr18Ni12Mo2Cu2?
- The closest equivalents of 06Cr18Ni12Mo2Cu2 (S31688) are SUS316J1 in JIS (common name: 316J1). Chemistry limits differ slightly, so dual certification depends on the actual heat.
- What are the mechanical properties of 06Cr18Ni12Mo2Cu2 plate?
- GB/T 4237-2015 Table 20 requires for 06Cr18Ni12Mo2Cu2: proof strength Rp0.2 ≥205 MPa, tensile strength ≥520 MPa and elongation ≥40%, hardness ≤187 HBW. Values apply to plate in the delivery heat-treated condition.
- Is 06Cr18Ni12Mo2Cu2 stainless steel magnetic?
- Not in the annealed condition. 06Cr18Ni12Mo2Cu2 is austenitic, so annealed plate is essentially non-magnetic; cold work can induce slight magnetism, mostly at cut and bent edges.
- What thickness of 06Cr18Ni12Mo2Cu2 plate can you supply?
- Under GB/T 4237 we supply 06Cr18Ni12Mo2Cu2 hot-rolled plate in 3 – 120 mm (to 150 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.
Conclusion
GB/T 4237 06Cr18Ni12Mo2Cu2 (S31688) is a molybdenum-bearing austenitic plate grade, known internationally as 316J1. It is defined by Table 15 chemistry (C ≤ 0.08, Cr 17.00 – 19.00, Ni 10.00 – 14.00, Mo 1.20 – 2.75, Cu 1.00 – 2.50) and Table 20 properties of at least 205 MPa proof strength and 520 MPa tensile strength. Typical uses include sulfuric acid handling equipment at low concentration, chemical plant parts in reducing media and pickling line components. Molybdenum can be as low as 1.20%, so pitting resistance in chlorides may be below 316.
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 06Cr18Ni12Mo2Cu2 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 06Cr17Ni12Mo2 S31608 and GB/T 4237 015Cr21Ni26Mo5Cu2 S31782, our GB/T 4237 category and the AISI 316 page. Send your sizes and quantities for a quotation.
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