ASME SA240 Type 316L UG Plate for Urea Reactor

GNEE keeps a large stock of 316L stainless steel plates for fast delivery, providing high-purity, high-corrosion-resistant, and highly reliable plate solutions for urea reactors and high-pressure chemical equipment.

 

 

Our urea-grade 316L stainless steel plates are produced through electric furnace refining + AOD decarburization and solution annealed at 1100–1150°C. Using optimized urea-grade 316LMod (724L / 1.4435) melting technology, the plates feature a fully austenitic structure with residual ferrite ≤0.6%, a PREN value of 35–38, and significantly better resistance to ammonium carbamate selective corrosion than standard 316L. They are ideal for severe high-pressure corrosive environments at 180–200°C, such as urea synthesis reactors and high-pressure ammonium carbamate condensers.

 

Production Process for Urea-Grade 316L Stainless Steel Plates

 

The corrosion resistance of the SS 316LUG Plate has passed key urea industry tests: corrosion rate ≤3.3 μm in the 48-hour Huey boiling test, no rust after 72-hour neutral salt spray testing, and long-term resistance to urea–ammonium carbamate media corrosion, delivering a service life more than three times longer than conventional 316L. (ISO 21457 technical specifications are recommended for reference.)

 

GNEE supplies 316LUG stainless steel plates with thicknesses from 3–80 mm, widths from 1500–3000 mm, and lengths from 3000–12000 mm. Available surface finishes include NO.1 hot rolled pickled and 2B cold rolled finished surfaces. We support custom cutting, polishing, and deep processing services. Dimensional tolerances are strictly controlled within ±0.02 mm, with flatness ≤3 mm/m. EN 10204 3.2 certificates, SGS/TUV material certifications, and Huey test reports are available upon request.

Attached below is our Mill Test Certificate：

 

ASME SA240 Type 316LUG Plate Specification

Standard	ASTM A240 / AISI / DIN / JIS / GB
Grade	201/202
	304/304L/304H/309S/310S/316L/316Ti/317L/321//S31803/S32205/904L
Thickness	0.3-6.0mm for cold sheet scope; 3.0-100mm for hot rolled scope
Width&Length	1000mm/1219mm/1500mm/1800mm/2000mm
	Length from cutting, as requirement
Surface	Mill surface: 2B/BA/No.1
	Processing surface: 8k mirror/Hairline/No.4 Satin/Bead blast/Color etched
Protection	Transparent film/ Blue fulm/PVC film or laser film
Package	Standard export package with metal pallet + angle bar protection +
Processing	Edging/Laser(Plasma/Water Jet) cutting/Leveling/Slitting

 

ASME SA240 316LUG  Chemical Composition

Grade	The Element Max (%)
	C	Mn	P	S	Si	Cr	Ni
ASME SA240 316L	0.030	2.00	0.045	0.030	0.75	16.0-18.0	10.0-14.0
	Mo	N	Cu	Cb
	2.0-3.0	0.10

 

ASME SA240 316LUG Mechanical Properties

UNS No	Grade	Proof Stress 0.2% (MPa)	Tensile Strength (MPa)	Elongation A5 (%)	Hardness Max
					HB	HRB
S31603	316L	170	485	40	217	95

 

What is the difference between 316L and 316L urea grade?

316L Urea Grade (316L UG or 316Lmod) is a specialized, high-performance variant of standard 316L stainless steel, specifically engineered for urea production environments. Its primary distinguishing features include an ultra-low silicon content (< 0.5%), elevated levels of molybdenum (> 2.5%) and nickel, and an extremely low ferrite content (< 0.5%), resulting in exceptional corrosion resistance against ammonium carbamate.

 

What is the required ferrite content for Urea-grade 316L stainless steel?

Ferrite undergoes preferential corrosion in urea-containing media. Typically, the ferrite content is required to be ≤ 0.5% or 0.6% (with even lower limits sometimes specified). Measurements are typically performed using a combination of magnetic methods (e.g., the Fischer Ferritoscope) and metallographic analysis.

 

Applications in Urea Reactors

Shell Fabrication: Used to construct the main shells of chemical reactors and storage tanks.
High-Pressure Environments: Suitable for high-pressure urea production environments.
Specialized Components: The 316LMod alloy is specifically designed for urea-carbonate environments; it is frequently the preferred choice-over standard 316L stainless steel for manufacturing critical reactor components.

 

316L Stainless Steel Plate Price per kg (Latest 2026)

As of early May 2026, 316L stainless steel plate prices are heavily influenced by rising raw material costs, with, for example, 316/316L sheets from China trading around $3.96–$4.22 per kg (FOB) for standard thicknesses. Prices are volatile due to a 15–40% increase in molybdenum and stable nickel costs, with higher rates seen for European or North American, with 316L being up to 52% more expensive than 304.

Click to get 316L stainless steel plate prices

 

Non-Destructive Testing (NDT)

As the urea reactor is a high-pressure vessel (High-Pressure Section), the integrity of the plate material is of paramount importance.
Ultrasonic Testing (UT): A 100% scan is performed in accordance with SA-578 grade standards to ensure that the interior of the plate is free from laminations, shrinkage cavities, or dense porosity.
Penetrant Testing (PT): Applied to machined bevels or high-stress areas to ensure the absence of any minute surface discontinuities.
Routine Testing: Tensile strength, yield strength, and elongation.
Hardness Testing: Ensures uniform hardness and prevents localized hard spots that could lead to stress corrosion cracking.

High-Quality Seafreight Packaging

Packaging Requirements: Urea-grade sheets or plates must be kept free from contact with carbon steel (to prevent iron ion contamination); the use of wooden pallets lined with plastic film is recommended.
Identification and Traceability: Each sheet or plate must bear clear stamped and stenciled markings to ensure full traceability of the heat treatment furnace number and chemical composition.