321 Stainless Steel Plate – Titanium-Stabilised High-Temperature Champion for 870 °C Welded Structures

When your equipment must survive continuous exposure between 425 °C and 850 °C, only 321 Stainless Steel Plate eliminates the risk of sensitisation and intergranular corrosion. The deliberate addition of titanium (≥5×C) locks up carbon as harmless TiC, preventing chromium depletion along grain boundaries during welding or long-term thermal cycling. This unique mechanism delivers full corrosion resistance after welding, excellent creep strength to 870 °C, and complete compatibility with standard welding procedures—making 321 stainless steel plate the undisputed standard for aircraft exhaust stacks, furnace baffles, thermal oxidizer shells, refinery flare stacks, and high-temperature expansion bellows worldwide.

Caption: 321 Stainless Steel Plate – Hot-Rolled No.1 Finish Direct from China's Top 321 Stainless Steel Plate Factory

Key Features & Benefits

Titanium stabilised (Ti ≥ 5×C) – immunity to sensitisation 425–850 °C
Continuous service to 870 °C; intermittent to 900 °C with minimal scaling
Excellent creep & stress-rupture strength above 600 °C
Superior weldability – no post-weld stabilising heat treatment required for most services
Fully austenitic – non-magnetic, even after heavy cold work
Available in both plate and 321 stainless steel bar or plate configurations
Full compliance – ASTM A240, ASME SA-240, AMS 5510, EN 1.4541, PED 2014/68/EU

Technical Specifications

Table 1 – Chemical Composition (ASTM A240)

Element	321 %	321H %	304 %	347 %
Cr	17.0–19.0	17.0–19.0	18.0–20.0	17.0–19.0
Ni	9.0–12.0	9.0–12.0	8.0–10.5	9.0–13.0
Ti	≥5×C	≥4×C	0	0
Nb	0	0	0	10×C
C (321)	≤0.08	0.04–0.10	≤0.08	≤0.08
Fe	Balance	Balance	Balance	Balance

Table 2 – Mechanical & Elevated-Temperature Properties

Property	Room Temp.	650 °C	870 °C
Tensile Strength	≥515 MPa	≥320 MPa	≥150 MPa
Yield Strength (0.2 %)	≥205 MPa	≥150 MPa	≥85 MPa
Elongation in 2"	≥40 %	≥28 %	≥30 %
Hardness HRB	≤92	—	—
Density	8.0 g/cm³ (0.289 lb/in³)	—	—
Thermal Expansion	17.2 µm/m·K (20–100 °C)	—	—

Standard Sizes & Thickness

Thickness (mm)	Standard Sizes (mm)	Weight (kg/m²)	Finish Options
3–12	1500 × 6000	24–96	No.1, pickled
12–30	2000 × 6000	96–240	No.1, HRAP
30–60	2000 × 6000	240–480	No.1, forged
60–100	2500 × 12000	480–800	No.1, forged

Custom cut-to-size and 304 stainless steel plate thickness from 3 mm to 100 mm available.

Product Range & Market Info

As one of the largest and most professional 321 stainless steel plate factory & 321 stainless steel plate manufacturer in China, we operate a 200 000 t/year Steckel mill with in-house solution annealing up to 1200 °C dedicated to 321 stainless steel plate production. Our 180 000 m² facility keeps 30 000 t of ready 321 stainless steel plate for sale in Shanghai and Houston, ensuring immediate availability for global aerospace and furnace builders. Whether you need one sheet of 10 mm × 1500 mm × 6000 mm or a full vessel of 80 mm × 2500 mm × 12000 mm, our mill-direct 321 stainless steel plate china pricing and ABS-approved quality give you the competitive edge. Contact our export team today for the most updated quotation and downloadable 3.1 MTC.

Specialty products include both plate and 321 stainless steel bar or plate – rounds, flats, and forgings manufactured under AMS 5510.

Caption: Massive Ready Stock of 321 Stainless Steel Plate for Sale – 321 Stainless Steel Plate Manufacturer with Full Traceability

Main Applications

Aircraft & piston engine exhaust systems – collector rings, flame tubes
Furnace plates & baffles – radiant tubes, muffles, baskets
Thermal oxidizer shells – flare stacks, reactor liners
Refinery flare stacks – high-temperature ducting
Expansion bellows – welded joints, flexible joints
High-temperature heat exchangers – tubesheets, shells
Superheater tubesheets – power station boilers
Chemical process vessels – operating 500–900 °C

Caption: Proven in 870 °C Service – 321 Stainless Steel Bar or Plate Used in Aviation & High-Temperature Applications

Why Choose Us – High-Temp Specialist

PED 2014/68/EU & TUV certified mill – EN 10204 3.1 & 3.2 MTC supplied
In-house solution annealing furnace up to 1200 °C – full metallurgical control
200 000 tons annual capacity – 5-day lead time for standard sizes
Same-day plasma/laser cutting – tolerances ±0.2 mm, beveling included
Full NDT service – UT, RT, PMI on every 321 stainless steel plate
Real-time stock portal – 24/7 visibility for any 321 stainless steel plate sizes

Grade Comparison Table: 321 vs 304 vs 316 vs 310S vs 347 vs 321H

Grade/Type	Ti %	Mo %	Max Temp (°C)	Weld Post-Treat	Relative Cost	Best Use
321/321H	≥5×C	0	870	Not needed	1.1×	High-temp welded
304	0	0	800	Not needed	1.0× (base)	General service
316	0	2–3	870	Not needed	1.35×	Marine chloride
310S	0	0	1150	Not needed	1.4×	Furnace radiant
347	Nb≥10×C	0	870	Not needed	1.2×	Nuclear welded

FAQ – 321 Stainless Steel Plate

What is the current pricing?
Mill-direct FOB China USD 2.60–3.00/kg depending on nickel and titanium surcharge; fixed for 48 h.
Stock status for 20 mm plate?
5 000 t ready inventory; live portal updated every 30 minutes.
Difference 321 vs 321H?
321H has 0.04–0.10 % carbon for higher creep strength; 321 is ≤0.08 % for better formability.
Lead time for 50 mm × 2000 × 6000 mm?
7 days production + 3–5 days ocean freight to Asian ports; 10 days to EU/US warehouses.
Welding recommendations?
TIG with ER321 filler; pre-heat not required; post-weld anneal optional for most high-temp services.
China factory advantages?
Mill-direct pricing, 200 000 t capacity, in-house 1200 °C annealing, same-day cutting, full NDT.
Do you supply both plate and bar?
Yes, full range of 321 stainless steel bar or plate – rounds, flats, forgings under AMS 5510.
Do you export worldwide?
Yes, to 70+ countries including USA, Germany, India, UAE, South Korea, and Brazil.

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Stop paying trader margins. Contact the most trusted 321 stainless steel plate manufacturer today for the latest price, immediate access to massive 321 stainless steel plate for sale stock, and same-day cutting of any 321 stainless steel plate sizes.