ASTM A240 304L Stainless Steel Plate UNS S30403 with Low Carbon and Weldability

Shaanxi Shangyou Stainless Steel Co., Ltd. supplies ASTM A240 304L stainless steel plate for global distributors, fabricators, equipment manufacturers, and EPC contractors requiring superior weldability and corrosion resistance. Produced to ASTM A240/A240M as UNS S30403 (also equivalent to EN 1.4307 and SUS 304L), this low-carbon austenitic stainless steel is specifically engineered for welded applications requiring immunity to intergranular corrosion.

The primary distinction of 304L versus standard 304 is its ultra-low carbon content—0.03% maximum compared to 0.08% for 304. This reduction effectively eliminates chromium carbide precipitation (sensitization) in the heat-affected zone during welding, enabling 304L to be used in the "as-welded" condition without requiring post-weld annealing. For this reason, 304L is the preferred grade for welded structures, heavy-gauge sections, and severe corrosive environments. The alloy offers slightly lower strength than 304 but provides excellent formability, toughness, and cryogenic performance.

ASTM A240 304L stainless steel plate is specified for welded applications requiring immunity to intergranular corrosion, particularly where post-weld annealing is impractical.

Typical applications include:

• Chemical processing tanks and pressure vessels
• Pharmaceutical and biotech equipment
• Heat exchangers and condensers
• Welded heavy-gauge structures
• Sanitary and food processing equipment

Key selection considerations: 304L is the preferred grade for heavy-gauge welded sections where post-weld heat treatment is not feasible. The slightly lower strength compared to 304 is generally acceptable for most applications. For chloride-rich environments, 316L is recommended. All standard welding methods apply, and 304L can be used in the as-welded condition.

Shangyou Stainless Steel provides value-added processing including cut-to-length, slitting, polishing, laser cutting, bending and forming, and protective film application.

All plates are packed with export-standard protection including protective paper between sheets, edge protection, steel strapping, waterproof wrapping, and wooden pallets or steel frames.

Quality documents include MTC 3.1, inspection reports, packing list, and heat number traceability. Third-party inspection (SGS, TUV, BV) can be arranged upon request.

304L has lower carbon content (≤0.03% vs ≤0.08% for 304), providing improved weldability and resistance to intergranular corrosion after welding. 304L can be used in the as-welded condition; 304 may require post-weld annealing for heavy sections. Strength is slightly lower for 304L: tensile ≥485 MPa vs ≥515 MPa for 304, yield ≥170 MPa vs ≥205 MPa.

304L is austenitic and non-magnetic in the annealed condition. Cold working such as bending, forming, or cutting may induce some magnetism. This is typical for austenitic stainless steels and does not affect corrosion resistance.

Cold rolled sheet from 0.3mm to 3.0mm; hot rolled plate from 3.0mm to 50.0mm. Heavier thicknesses available on request depending on grade and application.

304L offers oxidation resistance up to 900°C in continuous service and 815°C in intermittent service. However, continuous use at 425-860°C may reduce aqueous corrosion resistance if sensitization occurs.

MTC 3.1 per EN 10204, inspection reports, packing list, heat number traceability. Third-party inspection (SGS, TUV, BV) available upon request.

Yes. 304L offers excellent weldability. Low carbon content eliminates sensitization in the heat-affected zone, allowing welding without post-weld annealing. TIG, MIG, stick, and resistance welding methods are applicable.

Density ~7.90 g/cm³, melting point 1399-1454°C, elastic modulus ~193 GPa, thermal conductivity 16.3 W/m·K at 100°C.

Yes. 304L maintains excellent toughness down to cryogenic temperatures, making it suitable for low-temperature and cryogenic equipment.

Chemical processing tanks, pharmaceutical vessels, heat exchangers, welded pressure vessels, sanitary equipment, and heavy-gauge welded structures.

Yes. SGS, TUV, or BV inspection can be arranged upon request to meet project specifications.

Need ASTM A240 304L stainless steel plate for welded fabrication, chemical processing, or pharmaceutical equipment? Send requirements including grade, thickness/width/length, surface finish, quantity, and application.

Shangyou Stainless Steel provides custom sizes, processing, and export solutions for global B2B customers.