GB/T 4237 008Cr27Mo S12791 Stainless Steel Plate Supplier
008Cr27Mo S12791 plate at a glance
008Cr27Mo is the high-purity 26-1 super ferritic (ASTM XM-27, UNS S44627): C ≤0.010%, N ≤0.015%, Cr 25–27.5%, Mo 0.75–1.50%. Ultra-low interstitials keep it ductile and weldable despite 27% chromium.
Reading the designation: ‘008’ gives the carbon level (C ≤0.010% in GB/T 4237), followed by Cr27 = about 27% chromium; Mo = molybdenum added. S12791 is the unified numeric code (ISC) used in GB/T 4237-2015. Older drawings and Chinese buyers may still write the pre-2007 name 00Cr27Mo.
SHH STEEL produces and exports ferritic (super ferritic) stainless plate from China, works as a sales agent for leading stainless mills, and runs its own processing warehouse for cutting and surface finishing. 008Cr27Mo is part of our GB/T 4237 stainless plate range; for comparison, see our AISI 446 page.
How 008Cr27Mo performs in corrosive service
Super ferritics reach seawater-level pitting resistance (PREN 30–42) and are practically immune to chloride stress corrosion cracking.
PREN of 008Cr27Mo from the GB/T 4237 limits: 27.5 – 30.0. PREN is a ranking tool for pitting in chlorides, not a guarantee; temperature, crevices, deposits and weld finish matter as much.
Intergranular corrosion testing of ferritic and martensitic plate is by agreement (GB/T 4334 or ASTM A763 practices).
If service is harsher than 008Cr27Mo can handle, the next step up in this batch is GB/T 4237 008Cr30Mo2 S13091.
Chemical composition of 008Cr27Mo S12791
| Element | 008Cr27Mo heat analysis, % (Table 17) | Why it matters |
|---|---|---|
| C | ≤ 0.010 | Carbon. Low values protect welds from carbide precipitation; higher values add hot strength or hardenability. |
| Si | ≤ 0.40 | Silicon. Deoxidizer; in heat-resistant grades it builds a protective scale. |
| Mn | ≤ 0.40 | 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 | ≤ 0.020 | Sulfur. Impurity; low sulfur improves pitting resistance, hot workability and polishability. |
| Cr | 25.00 – 27.50 | Chromium. Forms the passive film; the main driver of corrosion and oxidation resistance. |
| Mo | 0.75 – 1.50 | Molybdenum. Raises pitting and crevice resistance in chlorides (×3.3 in PREN). |
| N | ≤ 0.015 | Nitrogen. Strengthens, stabilizes austenite and adds pitting resistance (×16 in PREN). |
| Other | Ni+Cu≤0.50 | Stabilizing / special-element requirement of the standard |
| PREN (Cr + 3.3Mo + 16N) | 27.5 – 30.0 (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 17.
Check analysis of 008Cr27Mo 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 008Cr27Mo 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 | ≤ 0.010 | +0.002 | ≤ 0.012 |
| Si | ≤ 0.40 | ±0.05 | ≤ 0.45 |
| Mn | ≤ 0.40 | ±0.03 | ≤ 0.43 |
| P | ≤ 0.030 | +0.005 | ≤ 0.035 |
| S | ≤ 0.020 | +0.005 | ≤ 0.025 |
| Cr | 25.00 – 27.50 | ±0.25 | 24.75 – 27.75 |
| Mo | 0.75 – 1.50 | ±0.05 | 0.70 – 1.55 |
| N | ≤ 0.015 | ±0.005 | ≤ 0.020 |
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 008Cr27Mo plate
| Property | 008Cr27Mo (Table 22) |
|---|---|
| Proof strength Rp0.2, MPa | ≥ 275 |
| Tensile strength Rm, MPa | ≥ 450 |
| Elongation A, % | ≥ 22 |
| Hardness HBW | ≤ 187 |
| Hardness HRB | ≤ 90 |
| Hardness HV | ≤ 200 |
| 180° bend (cold) | D=2a, no cracks on the outer surface |
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.
Living with a ferritic grade
008Cr27Mo is ferritic: it is magnetic, has lower thermal expansion and better thermal conductivity than austenitic steel, and is immune to chloride stress corrosion cracking. Those properties make it a good choice for heat exchangers, hot water tanks and exhaust parts.
The trade-off is toughness. Ferritic stainless has a ductile-brittle transition, and it moves to higher temperature with thickness and grain size. This is why ferritic plate is mostly thin; for sections above about 6 mm ask for Charpy data or bend in a warm shop.
Ferritic grades contain little or no nickel, so their price is far more stable than GB/T 4237 06Cr19Ni10 S30408 (304).
Fabrication guidance
High-purity super ferritics need complete gas shielding (trailing shield and back purge) because a few hundred ppm of picked-up C+N ruin weld toughness and corrosion resistance.
GTAW with matching filler or ERNiCrMo-3 is usual. Do not stress-relieve in the 400–550 °C range (475 °C embrittlement).
Cutting: we cut 008Cr27Mo 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 008Cr27Mo (GB/T 4237-2015 Annex C): 900 – 1 050 °C, rapid cooling.
High-purity ferritics are annealed and cooled rapidly; slow cooling through 400–550 °C and long holds at 600–900 °C must be avoided.
International equivalents of 008Cr27Mo S12791
| Standard system | Equivalent / closest grade |
|---|---|
| China GB/T 4237-2015 | 008Cr27Mo (S12791) |
| Former Chinese name | 00Cr27Mo |
| ASTM A240/A240M | XM-27 / S44627 |
| EN 10088-2 | — |
| JIS G4304 (hot rolled) | SUSXM27 |
| Common name | E-Brite 26-1-type |
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 446. See also our ASTM A240/A240M and JIS G4305 plate lists.
Choosing between 008Cr27Mo and its neighbours
The table compares 008Cr27Mo 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 |
|---|---|---|---|---|
| 008Cr27Mo S12791 | C ≤ 0.010, Cr 25.00 – 27.50, Mo 0.75 – 1.50, N ≤ 0.015 | 27.5 | 275 | 450 |
| GB/T 4237 008Cr30Mo2 S13091 | C ≤ 0.010, Cr 28.50 – 32.00, Ni ≤ 0.50, Mo 1.50 – 2.50, N ≤ 0.015, Cu ≤ 0.20 | 33.5 | 295 | 450 |
| GB/T 4237 022Cr27Ni2Mo4NbTi S12763 | C ≤ 0.030, Cr 25.00 – 28.00, Ni 1.00 – 3.50, Mo 3.00 – 4.00, N ≤ 0.040 | 34.9 | 450 | 585 |
| GB/T 4237 022Cr29Mo4NbTi S12963 | C ≤ 0.030, Cr 28.00 – 30.00, Ni ≤ 1.00, Mo 3.60 – 4.20, N ≤ 0.045 | 39.9 | 415 | 550 |
High-purity ferritics need vacuum or electron-beam refining; only a few mills produce them. Protect welds with full gas shielding, as nitrogen and carbon pickup destroys toughness.
Applications of 008Cr27Mo plate
Typical uses:
- Nitric and organic acid equipment
- Caustic soda evaporators
- Heat exchangers in chloride water
- Pulp and paper plant parts
Buyers specifying 008Cr27Mo for these jobs often compare it with GB/T 4237 008Cr30Mo2 S13091 and GB/T 4237 022Cr29Mo4NbTi S12963; the comparison table on this page shows the differences.
Other GB/T 4237 grades buyers request alongside it: GB/T 4237 10Cr17 S11710, GB/T 4237 022Cr12 S11203, GB/T 4237 022Cr12Ni S11213, GB/T 4237 022Cr18Ti S11863, GB/T 4237 019Cr19Mo2NbTi S11972, GB/T 4237 06Cr13Al S11348.
GB/T 4237 008Cr27Mo specification details
| 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 | 008Cr27Mo / S12791 |
| Steel class | Ferritic (super ferritic) |
| Chemical composition | Table 17 (heat analysis); product analysis per GB/T 222 |
| Mechanical properties | Table 22 |
| 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 | 2 – 8 mm |
| Delivery condition | 900 – 1 050 °C, rapid cooling |
| Surface | Hot rolled, heat treated, pickled (No.1 / 1D) as standard; ground or polished by agreement |
| Density | 7.67 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.
Sizes, tolerances and weight
| Dimension | Typical supply |
|---|---|
| Thickness | 2 – 8 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 (7.67 g/cm³). A 10 mm 008Cr27Mo plate weighs about 76.7 kg/m²; a 1 500 × 6 000 × 10 mm plate about 690 kg.
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 |
| Ground | Ground surface for defect removal or UT | On request |
| 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.
Quality documents supplied
- Heat chemical analysis on every heat; product analysis by agreement
- Tensile test (Rp0.2, Rm, A) per batch
- Hardness test
- 180° bend 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.
What to put on a 008Cr27Mo purchase order
- Standard and edition: GB/T 4237-2015
- Grade and code: 008Cr27Mo (S12791); 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.
Supply chain and lead time
008Cr27Mo 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.
FAQ
- What is 008Cr27Mo?
- 008Cr27Mo (S12791, old 00Cr27Mo) is a high-purity super ferritic with C ≤0.010% and N ≤0.015%, equivalent to ASTM XM-27 (S44627) and JIS SUSXM27. GB/T 4237-2015 minimums: 275 MPa proof, 450 MPa tensile.
- What is the chemical composition of 008Cr27Mo?
- Under GB/T 4237-2015 Table 17, 008Cr27Mo (S12791) has C ≤ 0.010, Cr 25.00 – 27.50, Mo 0.75 – 1.50, N ≤ 0.015; Ni+Cu≤0.50. Phosphorus is limited to ≤0.030% and sulfur to ≤0.020%.
- What is the ASTM equivalent of 008Cr27Mo?
- The closest equivalents of 008Cr27Mo (S12791) are XM-27 / S44627 in ASTM, SUSXM27 in JIS (common name: E-Brite 26-1-type). Chemistry limits differ slightly, so dual certification depends on the actual heat.
- What are the mechanical properties of 008Cr27Mo plate?
- GB/T 4237-2015 Table 22 requires for 008Cr27Mo: proof strength Rp0.2 ≥275 MPa, tensile strength ≥450 MPa and elongation ≥22%, hardness ≤187 HBW. Values apply to plate in the delivery heat-treated condition.
- Is 008Cr27Mo stainless steel magnetic?
- Yes. 008Cr27Mo is ferritic (super ferritic) and is magnetic in all conditions.
- What thickness of 008Cr27Mo plate can you supply?
- Under GB/T 4237 we supply 008Cr27Mo hot-rolled plate in 2 – 8 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 008Cr27Mo (S12791) is a high-purity super ferritic plate grade, known internationally as XM-27 / 26-1. It is defined by Table 17 chemistry (C ≤ 0.010, Cr 25.00 – 27.50, Mo 0.75 – 1.50, N ≤ 0.015) and Table 22 properties of at least 275 MPa proof strength and 450 MPa tensile strength. Typical uses include nitric and organic acid equipment, caustic soda evaporators and heat exchangers in chloride water. High-purity ferritics need vacuum or electron-beam refining; only a few mills produce them.
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 008Cr27Mo 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 008Cr30Mo2 S13091 and GB/T 4237 022Cr27Ni2Mo4NbTi S12763, our GB/T 4237 category and the AISI 446 page. Send your sizes and quantities for a quotation.
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