ASME SA387 Grade 21L Class 1 (SA387 Gr 21L Cl 1) Steel Plate

ASME SA387 Grade 21L Class 1 (SA387 Gr 21L Cl 1) alloy steel plates are a low-carbon variant in the ASME SA387 specification, designed for improved weldability while maintaining high performance. As a normalized grade, SA387 Gr 21L Cl 1 provides tensile strength (415–585 MPa) and yield strength (minimum 205 MPa) with excellent creep and oxidation resistance, suitable for environments where standard Grade 21 might pose welding challenges.

The SA387 Grade 21L Class 1 plates are manufactured using normalizing heat treatment, which enhances ductility and toughness at elevated temperatures, making them ideal for boilers, pressure vessels, and petrochemical equipment under severe high-heat conditions. The low carbon content (max 0.12%) minimizes hydrogen-induced cracking risks.

SHH STEEL supplies ASME SA387 Gr 21L Cl 1 alloy steel plates in a wide size range from 6mm to 100mm thickness, up to 4600mm width, and up to 12000mm length, meeting both ASME Section VIII pressure vessel code and customer-specific requirements.

As a production and export expert at SHH STEEL, we can confirm that ASME SA387 Grade 21L Class 1 alloy steel plates are governed by ASME SA-387/SA-387M, the standard for pressure vessel plates, alloy steel, chromium-molybdenum.

This specification outlines requirements for normalized plates for elevated temperature service, ensuring suitability for welded pressure vessels and boilers. SHH STEEL complies fully with this standard, providing plates in normalized conditions to optimize mechanical properties. Grade 21L is available only as Class 1.

The specification supports thicknesses from 6mm to 100mm, widths up to 4600mm, and lengths to 12000mm, with custom dimensions available for vessel designs. Ultrasonic examination per ASME SA-578 Class 1 detects laminations, guaranteeing defect-free material, while dual certification with ASTM A387 Gr 21L Cl 1 or EN 10028-2 is offered for international compatibility.

This makes our ASME SA387 Gr 21L Cl 1 plates a reliable choice for global buyers, supported by mill test certificates for complete traceability.

At SHH STEEL, we ensure the chemical composition of ASME SA387 Grade 21L Class 1 is tightly controlled per ASME SA-387/SA-387M to guarantee elevated temperature stability and weldability.

The maximum carbon content is 0.12%, preventing brittleness while improving weldability, manganese (0.30-0.60%) enhances strength. Phosphorus and sulfur are capped at 0.025% each to minimize cracking, chromium (3.00-3.50%) and molybdenum (1.00-1.50%) provide creep resistance.

Our testing per ASME SA-350 maintains a Carbon Equivalent (CE) ≤0.45 per AWS D1.1. Melt analysis (heat analysis) and product analysis differ slightly with tolerances. Melt analysis is stricter for ladle chemistry, while product analysis allows variation for finished plates.

This ensures consistency, making ASME SA387 Gr 21L Cl 1 plates a reliable choice for buyers searching for “ASME SA387 Gr 21L Cl 1 chemical composition.”

As a production and export expert at SHH STEEL, we can assure you that ASME SA387 Grade 21L Class 1 pressure vessel steel plates deliver strong mechanical properties, tested per ASME SA-370 for tensile/yield, ASME SA-23 for impact, and ASME SA-466 for fatigue.

With a minimum yield strength of 205 MPa and tensile range of 415-585 MPa, these plates support load-bearing in high-temp environments, while 19% elongation ensures ductility for forming. The impact energy of 27J typical prevents brittle failure, and the modulus of elasticity (200 GPa) provides structural stability.

The fatigue limit (200 MPa est.) varies with surface finish, optimized by our grinding process. This makes ASME SA387 Gr 21L Cl 1 plates a reliable choice for buyers searching for “ASME SA387 Gr 21L Cl 1 mechanical properties.”

SHH STEEL provides ASME SA387 Gr 21L Cl 1 plates in normalized condition as standard, heated to 900-950°C and air-cooled, with minimum tempering at 675°C to improve toughness for elevated temperature applications.

Plates are delivered with as-rolled or stress-relieved options for flexibility, including heat numbers for traceability. Our global shipping ensures timely delivery, with 3-7 days to Asia for standard orders.

We maintain strict tolerances per ASME SA-20: thickness ±1.5mm for <40mm and ±2.0mm for thicker up to 100mm; width/length ±10mm (or ±5mm custom); flatness 3mm per meter. EN 10029 Class B available for European compatibility.

ASME SA387 Gr 21L Cl 1 is highly weldable with low CE ≤0.45 per AWS D1.1. SHH STEEL recommends preheating at 150-200°C for thicknesses over 25mm to prevent hydrogen-induced cracking, with post-weld heat treatment (PWHT) at 620-650°C for stress relief. Supported processes include GTAW, SMAW, and GMAW with E7018 filler (AWS A5.1), achieving 90-95% joint efficiency per ASME Section IX. Low sulfur (≤0.025%) reduces hot shortness, and 19% elongation ensures ductility. Testing includes bend tests (ASTM E190) for 3t radius and ultrasonic for weld integrity per ASTM A435.

Global equivalents for ASME SA387 Gr 21L Cl 1 facilitate international projects, offering similar tensile and yield properties for pressure vessel use. For example, 13CrMoV9-10 (EN 10028-2) is a European equivalent with 440-590 MPa tensile and 290 MPa yield, suitable for EU boilers. STBA29 (JIS G4109) serves Japanese applications with 440-590 MPa tensile and 290 MPa yield, ideal for high-strength vessels. 12Cr3MoVSiTiB (GB/T 713) is the Chinese standard equivalent, providing 440-590 MPa tensile and 295 MPa yield for cost-effective high-temperature equipment in Asian markets. These equivalents ensure cross-compatibility, allowing buyers to substitute ASME SA387 Gr 21L Cl 1 plates seamlessly in global supply chains.

Supplementary requirements for ASME SA387 Gr 21L Cl 1 pressure vessel steel plates enhance performance for specialized applications. They offer buyers tailored options.

These include ultrasonic testing (Class 1 per ASTM A435 for no laminations >0.25% thickness). Charpy impact at -50°C (27J min per ASTM A20 for cold service) is another. Heat analysis per heat number (ASTM E350 for traceability) ensures quality. Product analysis allows ±0.02% tolerance on elements. Shot blasting to Sa 2.5 (50-100μm profile per ISO 8501-1) is available for surface preparation.

SHH STEEL provides these to meet stringent needs. Buyers search for “SA387 Gr 21L Cl 1 supplementary requirements.”

ASME SA387 Gr 21L Cl 1 pressure vessel steel plates are versatile for elevated-temperature and pressure environments. They have good toughness and formability.

Details: Pressure vessels benefit from 415-585 MPa tensile at 600°C. Boilers handle 600°C with 19% elongation for forming. Heat exchangers use 6-30mm plates for 150 bar at 550°C. Storage tanks leverage 30-80mm for 100 bar at 550°C per API 650. Steam drums utilize 20-60mm plates for 250 bar at 600°C, per ASME Section VIII for efficient steam generation.

SHH STEEL offers ASME and ASTM-certified SA387 Gr 21L Cl 1 plates. We provide custom thicknesses up to 300mm. Heat treatments are tailored to your project. Our 15-year track record includes zero defect deliveries to 50+ countries. This is backed by SGS verification and mill test certificates.

SHH STEEL’s ASME SA387 Gr 21L Cl 1 Pressure Vessel Steel Plates provide unmatched strength and reliability for high-temperature pressure vessels and boilers. With precise tolerances, superior weldability, and global equivalents, we offer customized solutions. Trust SHH STEEL for your steel needs.