GB/T 4237 06Cr17Ni12Mo2Nb S31678 Stainless Steel Plate Supplier
GB/T 4237 06Cr17Ni12Mo2Nb: what it is and who uses it
06Cr17Ni12Mo2Nb is 316Cb (EN 1.4580): niobium 10 × C to 1.10% stabilizes carbon. Niobium carbides survive welding better than titanium carbides, which is why some specifiers choose it over 316Ti for welded high-temperature parts.
Reading the designation: ’06’ gives the carbon level (C ≤0.08% in GB/T 4237), followed by Cr17 = about 17% chromium; Ni12 = about 12% nickel; Mo2 = about 2% molybdenum; Nb = niobium added. S31678 is the unified numeric code (ISC) used in GB/T 4237-2015.
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. 06Cr17Ni12Mo2Nb is part of our GB/T 4237 stainless plate range; for comparison, see our ASTM A240 Type 316Ti page.
Chemical composition of 06Cr17Ni12Mo2Nb S31678
| Element | 06Cr17Ni12Mo2Nb 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 | ≤ 0.75 | 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 | 16.00 – 18.00 | 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 | 2.00 – 3.00 | Molybdenum. Raises pitting and crevice resistance in chlorides (×3.3 in PREN). |
| N | ≤ 0.10 | Nitrogen. Strengthens, stabilizes austenite and adds pitting resistance (×16 in PREN). |
| Other | Nb: 10 × C – 1.10 | Stabilizing / special-element requirement of the standard |
| PREN (Cr + 3.3Mo + 16N) | 22.6 – 25.2 (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.
Check analysis of 06Cr17Ni12Mo2Nb plate
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 06Cr17Ni12Mo2Nb 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 | ≤ 0.75 | ±0.05 | ≤ 0.80 |
| Mn | ≤ 2.00 | ±0.04 | ≤ 2.04 |
| P | ≤ 0.045 | +0.010 | ≤ 0.055 |
| S | ≤ 0.030 | +0.005 | ≤ 0.035 |
| Cr | 16.00 – 18.00 | ±0.20 | 15.80 – 18.20 |
| Ni | 10.00 – 14.00 | ±0.10 (min) / ±0.15 (max) | 9.90 – 14.15 |
| Mo | 2.00 – 3.00 | ±0.10 | 1.90 – 3.10 |
| N | ≤ 0.10 | ±0.01 | ≤ 0.11 |
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 06Cr17Ni12Mo2Nb plate
| Property | 06Cr17Ni12Mo2Nb (Table 20) |
|---|---|
| Proof strength Rp0.2, MPa | ≥ 205 |
| Tensile strength Rm, MPa | ≥ 515 |
| Elongation A, % | ≥ 30 |
| Hardness HBW | ≤ 217 |
| Hardness HRB | ≤ 95 |
| Hardness HV | ≤ 220 |
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 06Cr17Ni12Mo2Nb
Molybdenum raises resistance to chlorides, sulfurous media and reducing acids. The low-carbon and nitrogen variants keep that resistance across welds.
PREN of 06Cr17Ni12Mo2Nb from the GB/T 4237 limits: 22.6 – 25.2. 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.
06Cr17Ni12Mo2Nb equivalent grades: ASTM, EN, JIS
| Standard system | Equivalent / closest grade |
|---|---|
| China GB/T 4237-2015 | 06Cr17Ni12Mo2Nb (S31678) |
| ASTM A240/A240M | Type 316Cb / S31640 |
| EN 10088-2 | X6CrNiMoNb17-12-2 / 1.4580 |
| JIS G4304 (hot rolled) | — |
| Common name | 316Nb |
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 316Ti, AISI 316Ti. 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 | 06Cr17Ni12Mo2Nb / S31678 |
| 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 | ≥ 1 040 °C, water quench or other 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.
Choosing between 06Cr17Ni12Mo2Nb and its neighbours
The table compares 06Cr17Ni12Mo2Nb 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 |
|---|---|---|---|---|
| 06Cr17Ni12Mo2Nb S31678 | 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 06Cr17Ni12Mo2Ti S31668 | C ≤ 0.08, Cr 16.00 – 18.00, Ni 10.00 – 14.00, Mo 2.00 – 3.00 | 22.6 | 205 | 515 |
| GB/T 4237 06Cr18Ni11Nb S34778 | C ≤ 0.08, Cr 17.00 – 19.00, Ni 9.00 – 13.00 | 17.0 | 205 | 515 |
| 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 |
Elongation minimum is 30% (Table 20), lower than 316L. Supply is by mill order; plan lead time. Niobium-bearing welds can be prone to hot cracking; use a matched filler such as ER318 (19-12-3 Nb).
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 06Cr17Ni12Mo2Nb 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.
How 06Cr17Ni12Mo2Nb plate is heat treated
Recommended heat treatment for 06Cr17Ni12Mo2Nb (GB/T 4237-2015 Annex C): ≥ 1 040 °C, water quench or other rapid cooling.
Cool rapidly through 850–450 °C after annealing; slow cooling of thick Mo-bearing plate risks carbide and sigma precipitation.
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.
Applications of 06Cr17Ni12Mo2Nb plate
Where buyers specify it:
- Welded chemical and petrochemical equipment
- High-temperature parts with corrosive condensate
- Nuclear and power plant internals (European practice)
Buyers specifying 06Cr17Ni12Mo2Nb for these jobs often compare it with GB/T 4237 06Cr17Ni12Mo2Ti S31668 and GB/T 4237 06Cr17Ni12Mo2 S31608; the comparison table on this page shows the differences.
International grade pages for the alternatives mentioned above: ASTM A240 Type 347, ASTM A240 Type 316.
Other GB/T 4237 grades buyers request alongside it: GB/T 4237 022Cr17Ni12Mo2 S31603, 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 06Cr17Ni12Mo2Nb plate weighs about 80.0 kg/m²; a 1 500 × 6 000 × 10 mm plate about 720 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
- 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.
Mill sourcing and lead time
06Cr17Ni12Mo2Nb 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 06Cr17Ni12Mo2Nb purchase order
- Standard and edition: GB/T 4237-2015
- Grade and code: 06Cr17Ni12Mo2Nb (S31678); 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.
Why buy from 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 the equivalent of 06Cr17Ni12Mo2Nb?
- 06Cr17Ni12Mo2Nb (S31678) corresponds to EN 1.4580 X6CrNiMoNb17-12-2 and ASTM A240 Type 316Cb (S31640). JIS has no direct equivalent. It is 316 stabilized with Nb 10×C–1.10%.
- What is the chemical composition of 06Cr17Ni12Mo2Nb?
- Under GB/T 4237-2015 Table 15, 06Cr17Ni12Mo2Nb (S31678) has C ≤ 0.08, Cr 16.00 – 18.00, Ni 10.00 – 14.00, Mo 2.00 – 3.00, N ≤ 0.10; Nb: 10 × C – 1.10. Phosphorus is limited to ≤0.045% and sulfur to ≤0.030%.
- What are the mechanical properties of 06Cr17Ni12Mo2Nb plate?
- GB/T 4237-2015 Table 20 requires for 06Cr17Ni12Mo2Nb: proof strength Rp0.2 ≥205 MPa, tensile strength ≥515 MPa and elongation ≥30%, hardness ≤217 HBW. Values apply to plate in the delivery heat-treated condition.
- Is 06Cr17Ni12Mo2Nb stainless steel magnetic?
- Not in the annealed condition. 06Cr17Ni12Mo2Nb is austenitic, so annealed plate is essentially non-magnetic; cold work can induce slight magnetism, mostly at cut and bent edges.
- What thickness of 06Cr17Ni12Mo2Nb plate can you supply?
- Under GB/T 4237 we supply 06Cr17Ni12Mo2Nb 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.
- What is the PREN of 06Cr17Ni12Mo2Nb?
- Using PREN = Cr + 3.3Mo + 16N and the GB/T 4237-2015 limits, 06Cr17Ni12Mo2Nb has a PREN of about 22.6 at minimum chemistry and 25.2 at mid-range.
Conclusion
GB/T 4237 06Cr17Ni12Mo2Nb (S31678) is a molybdenum-bearing austenitic plate grade, known internationally as 316Nb / 316Cb. It is defined by Table 15 chemistry (C ≤ 0.08, Cr 16.00 – 18.00, Ni 10.00 – 14.00, Mo 2.00 – 3.00, N ≤ 0.10) and Table 20 properties of at least 205 MPa proof strength and 515 MPa tensile strength. Typical uses include welded chemical and petrochemical equipment, high-temperature parts with corrosive condensate and nuclear and power plant internals. Elongation minimum is 30% (Table 20), lower than 316L.
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 06Cr17Ni12Mo2Nb 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 06Cr17Ni12Mo2Ti S31668 and GB/T 4237 06Cr18Ni11Nb S34778, our GB/T 4237 category and the ASTM A240 Type 316Ti page. Send your sizes and quantities for a quotation.
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