GB/T 4237 12Cr18Ni9 S30210 Stainless Steel Plate Supplier

12Cr18Ni9 is 302, the older high-carbon 18-8 grade (C ≤0.15%). It has the same 205/515 MPa minimums as 304 but hardens faster when cold worked, which is why Annex B lists it for building decoration parts.

How to read the name: under GB/T 20878 the leading ’12’ is the carbon code (here C ≤0.15%), then Cr18 = about 18% chromium; Ni9 = about 9% nickel. S30210 is the unified numeric code (ISC) used in GB/T 4237-2015. Older drawings and Chinese buyers may still write the pre-2007 name 1Cr18Ni9.

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. 12Cr18Ni9 is part of our GB/T 4237 stainless plate range; for comparison, see our AISI 302 page.

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.

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.

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 12Cr18Ni9 limits. Deviations apply to one side of a range only, never to both sides in the same heat.

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.

Strength minimums apply to solution-treated plate tested transverse to rolling. Actual mill results are usually well above these minimums and are reported on the certificate.

The lean-nickel 17-7 and older 18-8 grades are chosen for work hardening, cold forming or non-magnetic behaviour more than for corrosion resistance.

12Cr18Ni9 sits in this family as 302.

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 302, JIS G4305 SUS302. See also our ASTM A240/A240M and JIS G4305 plate lists.

The table compares 12Cr18Ni9 with the grades buyers most often weigh it against. Strength values are GB/T 4237-2015 minimums; PREN is calculated from the minimum chemistry.

For anything welded and wet, prefer 06Cr19Ni10 or 022Cr19Ni10: high carbon makes 302 weld zones prone to sensitization. 302 plate is rarely stocked thick; we mill-order or offer 304 where the drawing allows.

Austenitic 18-8 grades resist atmospheric corrosion, fresh water, foods, nitric acid and most organic acids. They are vulnerable to chlorides (pitting, crevice and stress corrosion cracking above about 60 °C).

PREN of 12Cr18Ni9 from the GB/T 4237 limits: 17.0 – 18.0. 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.

Recommended heat treatment for 12Cr18Ni9 (GB/T 4237-2015 Annex C): ≥ 1 040 °C, water quench or other rapid cooling.

Solution treatment dissolves carbides and restores full corrosion resistance and ductility. Hot forming should finish above about 900 °C and be followed by a new solution anneal if the part is used in corrosive service.

Austenitic 18-8 plate welds well with every arc process (SMAW, GTAW, GMAW, SAW, FCAW). Use ER308L/E308L filler for 304 and 304L, ER347 where the joint must resist sensitization at high carbon, and ER308H for H grades.

Keep interpass temperature below about 150 °C, avoid preheat, and remove heat tint by pickling or brushing with stainless brushes. Distortion is higher than with carbon steel because thermal expansion is about 50% greater and conductivity much lower; plan tacking sequence and fixtures.

Cold forming: austenitic plate bends to tight radii (inside radius ≈ thickness for most gauges) but springs back more than carbon steel.

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.

Weight: plate mass in kg/m² = thickness (mm) × density (7.93 g/cm³). A 10 mm 12Cr18Ni9 plate weighs about 79.3 kg/m²; a 1 500 × 6 000 × 10 mm plate about 714 kg.

Typical end uses we ship this grade for:

• Architectural decoration and trim
• Springs and clips (strip)
• Cold-formed brackets
• Kitchen equipment parts

Buyers specifying 12Cr18Ni9 for these jobs often compare it with GB/T 4237 06Cr19Ni10 S30408 and GB/T 4237 12Cr18Ni9Si3 S30240; the comparison table on this page shows the differences.

International grade pages for the alternatives mentioned above: ASTM A240 Type 304, ASTM A240 Type 301, AISI 302B.

• 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.

• Standard and edition: GB/T 4237-2015
• Grade and code: 12Cr18Ni9 (S30210); 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.

12Cr18Ni9 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.

• 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.

GB/T 4237 12Cr18Ni9 (S30210) is a 18-8 chromium-nickel austenitic plate grade, known internationally as 302. It is defined by Table 15 chemistry (C ≤ 0.15, Cr 17.00 – 19.00, Ni 8.00 – 10.00, N ≤ 0.10) and Table 20 properties of at least 205 MPa proof strength and 515 MPa tensile strength. Typical uses include architectural decoration and trim, springs and clips and cold-formed brackets. For anything welded and wet, prefer 06Cr19Ni10 or 022Cr19Ni10: high carbon makes 302 weld zones prone to sensitization.

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 12Cr18Ni9 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 06Cr19Ni10 S30408 and GB/T 4237 12Cr17Ni7 S30110, our GB/T 4237 category and the AISI 302 page. Send your sizes and quantities for a quotation.