ASME SA387 Grade 12 Class 1 (SA387 Gr 12 Cl 1) Steel Plate

ASME SA387 Grade 12 Class 1 (SA387 Gr 12 Cl 1) Steel Plate

ASME SA387 Grade 12 Class 1 alloy steel plates are normalized for high-temperature pressure vessels. With 450-585 MPa tensile and 275 MPa yield, they suit 550°C, 300 bar use per ASME Section VIII, supplied by SHH STEEL.
Specification
ASME SA-387/SA-387M for chromium-molybdenum alloy steel plates in pressure vessels
Dimensions
6-100mm thick, 4600mm max wide, 12000mm max long
Hardness/Density
ASME SA387 Gr 12 Cl 1 Hardness 150-220 HB, Density 7.85 g/cm³
Equivalent Material
10CrMo9-10 (EN10028-2), STBA24 (JIS G4109), 10CrMo910 (GB/T 713)
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General Description
Material Specification
Chemical Composition
Mechanical Properties
Heat Treatment
Delivery
Tolerances
Weldability
Equivalent Grades
Supplementary
Applications
Why Choose Us
FAQ
Conclusion

What is ASME SA387 Grade 12 Class 1?

ASME SA387 Grade 12 Class 1 (SA387 Gr 12 Cl 1) alloy steel plates are a higher chrome-moly grade in the ASME SA387 specification. While Class 2 is quenched and tempered for enhanced performance, Class 1 is normalized, providing tensile strength (450–585 MPa) and yield strength (minimum 275 MPa) with robust creep and oxidation resistance.

The plates are manufactured using normalizing heat treatment, which improves ductility and toughness at elevated temperatures, making them suitable for boilers, pressure vessels, and petrochemical equipment under severe high-heat conditions.

SHH STEEL supplies ASME SA387 Grade 12 Class 1 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.

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asme sa387 grade 91 class 2asme sa387 grade 22 class 2asme sa387 grade 21 class 2
asme sa387 grade 22l class 1asme sa387 grade 12 class 1asme sa387 grade 11 class 1
asme sa387 grade 9 class 2asme sa387 grade 22 class 1asme sa387 grade 12 class 2
asme sa387 grade 9 class 1asme sa387 grade 5 class 2asme sa387 grade 2 class 1
asme sa387 grade 5 class 1 asme sa387 grade 21 class 1asme sa387 grade 21l class 1

Material Specification

As a production and export expert at SHH STEEL, we can confirm that ASME SA387 Grade 12 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.

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 12 Cl 1 or EN 10028-2 is offered for international compatibility.

This makes our ASME SA387 Gr 12 Cl 1 plates a reliable choice for global buyers, supported by mill test certificates for complete traceability.

Specification ElementRequirementSHH STEEL ComplianceKeywords
Primary StandardASME SA-387/SA-387MASME Section VIIISA387 Gr 12 Cl 1 specification
Thickness Range6mm-100mm (custom)Mill Test CertificateSA387 Gr 12 Cl 1 dimensions
Width/LengthUp to 4600mm / 12000mmCustom fabrication availableSA387 Gr 12 Cl 1 size options
Ultrasonic TestingNo laminations >0.25% thicknessClass 1 per ASME SA-578SA387 Gr 12 Cl 1 inspection
Heat TreatmentNormalized900-950°C furnace controlSA387 Gr 12 Cl 1 heat treat

ASME SA387 Grade 12 Class 1 Chemical Composition

We ensure the chemical composition of ASME SA387 Grade 12 Class 1 is tightly controlled per ASME SA-387/SA-387M to guarantee elevated temperature stability and weldability.

The maximum carbon content is 0.17%, preventing brittleness, while manganese (0.40-0.65%) and silicon (0.50-0.80%) enhance strength and deoxidation. Phosphorus and sulfur are capped at 0.025% each to minimize cracking, chromium (1.00-1.50%) and molybdenum (0.45-0.65%) 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 12 Cl 1 plates a reliable choice for buyers searching for “ASME SA387 Gr 12 Cl 1 chemical composition.”

ElementMelt Analysis (%)Product Analysis (%)Standard LimitTest MethodRoleKeywords
Carbon (C)0.05-0.170.04-0.180.17 maxASME SA-350Strength without brittlenessSA387 Gr 12 Cl 1 carbon
Manganese (Mn)0.40-0.650.35-0.730.40-0.65ASME SA-350Toughness, hardenabilitySA387 Gr 12 Cl 1 manganese
Phosphorus (P)≤0.025≤0.0250.025 maxASME SA-350Reduces brittlenessSA387 Gr 12 Cl 1 phosphorus
Sulfur (S)≤0.025≤0.0250.025 maxASME SA-350Improves weldabilitySA387 Gr 12 Cl 1 sulfur
Silicon (Si)0.50-0.800.44-0.860.50-0.80ASME SA-350Deoxidation, fluiditySA387 Gr 12 Cl 1 silicon
Chromium (Cr)1.00-1.500.94-1.561.00-1.50ASME SA-350Corrosion resistanceSA387 Gr 12 Cl 1 chromium
Molybdenum (Mo)0.45-0.650.40-0.700.45-0.65ASME SA-350Creep resistanceSA387 Gr 12 Cl 1 molybdenum

ASME SA387 Grade 12 Class 1 Mechanical Properties

As a production and export expert at SHH STEEL, we can assure you that ASME SA387 Grade 12 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 275 MPa and tensile range of 450-585 MPa, these plates support load-bearing in high-temp environments, while 22% 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 (210 MPa est.) varies with surface finish, optimized by our grinding process. This makes ASME SA387 Gr 12 Cl 1 plates a reliable choice for buyers searching for “ASME SA387 Gr 12 Cl 1 mechanical properties.”

PropertyValueTest MethodTemperature (°C)Thickness EffectKeywords
Tensile Strength450-585 MPaASME SA-370Ambient-5% >100mmSA387 Gr 12 Cl 1 tensile
Yield Strength275 MPa (min)ASME SA-370AmbientStable to 100mmSA387 Gr 12 Cl 1 yield
Elongation22% (min)ASME SA-370Ambient20-24% (6-25mm)SA387 Gr 12 Cl 1 elongation
Impact Energy27J typicalASME SA-23AmbientAll thicknessesSA387 Gr 12 Cl 1 impact
Modulus of Elasticity200 GPaASME SA-111AmbientConstantSA387 Gr 12 Cl 1 modulus
Fatigue Limit210 MPa (est.)ASME SA-466AmbientVaries with surfaceSA387 Gr 12 Cl 1 fatigue

Heat Treatment

SHH STEEL provides ASME SA387 Gr 12 Cl 1 plates in normalized condition as standard, heated to 900-950°C and air-cooled to improve toughness for elevated temperature applications.

FactorValue/ConditionStandardRecommendedKeywords
Heat TreatmentNormalized at 900-950°CASME SA387Standard conditionSA387 Gr 12 Cl 1 heat treat

Delivery

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.

FactorValue/ConditionStandardRecommendedKeywords
Delivery ConditionNormalizedASME SA-20Transit 3-7 days AsiaSA387 Gr 12 Cl 1 delivery

Tolerances

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.

FactorValue/ConditionStandardRecommendedKeywords
Thickness Tolerance (<40mm)±1.5mmASME SA-206-40mmSA387 Gr 12 Cl 1 tolerance
Flatness3mm per meterASME SA-20AllSA387 Gr 12 Cl 1 flatness

 

Weldability

ASME SA387 Gr 12 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 22% elongation ensures ductility. Testing includes bend tests (ASTM E190) for 3t radius and ultrasonic for weld integrity per ASTM A435.

Weldability FactorValue/ConditionStandardRecommended ProcessKeywords
Carbon Equivalent (CE)≤0.45AWS D1.1GTAW, SMAWSA387 Gr 12 Cl 1 weldability
Preheating (°C)150-200 (>25mm)ASME Section IXGMAWSA387 Gr 12 Cl 1 welding
PWHT (°C)620-650ASME SA-20AllSA387 Gr 12 Cl 1 heat treat
Filler MetalE7018AWS A5.1SMAWSA387 Gr 12 Cl 1 welding rod
Bend Test Radius (mm)3t (t=thickness)ASTM E190AllSA387 Gr 12 Cl 1 bend test

ASME SA387 Grade 12 Class 1 Equivalent Grades

Global equivalents for ASME SA387 Gr 12 Cl 1 facilitate international projects, offering similar tensile and yield properties for pressure vessel use. For example, 10CrMo9-10 (EN 10028-2) is a European equivalent with 480-630 MPa tensile and 280 MPa yield, suitable for EU boilers. STBA24 (JIS G4109) serves Japanese applications with 480-630 MPa tensile and 280 MPa yield, ideal for high-strength vessels. 10CrMo910 (GB/T 713) is the Chinese standard equivalent, providing 480-630 MPa tensile and 280 MPa yield for cost-effective high-temperature equipment in Asian markets. These equivalents ensure cross-compatibility, allowing buyers to substitute ASME SA387 Gr 12 Cl 1 plates seamlessly in global supply chains.

GradeStandardTensile (MPa)Yield (MPa)Elongation (%)Impact (J @ -20°C)Keywords
SA387 Gr 12 Cl 1ASME SA-387/SA-387M450-5852752227SA387 Gr 12 Cl 1 equivalent
10CrMo9-10EN 10028-2480-6302802027SA387 Gr 12 Cl 1 EN grade
STBA24JIS G4109480-6302802027SA387 Gr 12 Cl 1 JIS grade
10CrMo910GB/T 713480-6302801927SA387 Gr 12 Cl 1 GB grade
A387 Gr.12 Cl.1ASTM A387450-5852752234SA387 Gr 12 Cl 1 alternative
A516 Gr.60ASTM A516415-5502202127SA387 Gr 12 Cl 1 similar alt

Supplementary Requirements

Supplementary requirements for ASME SA387 Gr 12 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 12 Cl 1 supplementary requirements.”

RequirementDetailStandardTest FrequencyApplicable Thickness (mm)Keywords
Ultrasonic TestingClass 1, no laminationsASTM A435Full plate6-100SA387 Gr 12 Cl 1 ultrasonic
Charpy Impact-50°C, 27J minASTM A20Per heat6-100SA387 Gr 12 Cl 1 cold impact
Heat AnalysisPer heat numberASTM E350Each batchAllSA387 Gr 12 Cl 1 analysis
Product Analysis±0.02% toleranceASTM E350Sample per lotAllSA387 Gr 12 Cl 1 product test
Shot BlastingSa 2.5, 50-100μm profileISO 8501-1On request6-50SA387 Gr 12 Cl 1 blasting

 

Applications

ASME SA387 Gr 12 Cl 1 pressure vessel steel plates are versatile for elevated-temperature and pressure environments. They have good toughness and formability.

ApplicationTemperature (°C)Pressure (bar)Thickness (mm)Standard ComplianceKeywords
Pressure VesselsUp to 55030020-100ASME Section VIIISA387 Gr 12 Cl 1 vessels
BoilersUp to 55020010-50ASME Section ISA387 Gr 12 Cl 1 boilers
Heat ExchangersUp to 5001506-30TEMA StandardsSA387 Gr 12 Cl 1 heat exchange
Storage TanksUp to 45010030-80API 650SA387 Gr 12 Cl 1 tanks
Steam DrumsUp to 55025020-60ASME Section VIIISA387 Gr 12 Cl 1 steam drums

Details: Pressure vessels benefit from 450-585 MPa tensile at 550°C. Boilers handle 550°C with 22% elongation for forming. Heat exchangers use 6-30mm plates for 150 bar at 500°C. Storage tanks leverage 30-80mm for 100 bar at 450°C per API 650. Steam drums utilize 20-60mm plates for 250 bar at 550°C, per ASME Section VIII for efficient steam generation.

Why Choose SHH STEEL

SHH STEEL offers ASME and ASTM-certified SA387 Gr 12 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.

AdvantageBenefitKeywords
Expert CertificationASME Section VIII compliantSA387 Gr 12 Cl 1 certified
Custom FabricationUp to 300mm thicknessSA387 Gr 12 Cl 1 custom
Proven Reliability50+ countries, zero rejectsSA387 Gr 12 Cl 1 trusted supplier

FAQ

What is ASME SA387 Grade 12 Class 1 used for?
ASME SA387 Grade 12 Class 1 is widely used for high-temperature pressure vessels, boilers, and heat exchangers in power generation and petrochemical industries. It handles temperatures up to 550°C and pressures to 300 bar, with 450-585 MPa tensile strength ensuring reliability. SHH STEEL supplies these for welded constructions per ASME Section VIII Division 1.
What is the difference between SA387 Gr 12 Cl 1 and SA387 Gr 12 Cl 2?
SA387 Gr 12 Cl 1 is normalized with 275 MPa yield for standard service, while Gr 12 Cl 2 is quenched and tempered with 345 MPa yield for higher strength. SHH STEEL recommends Gr 12 Cl 1 for moderate loads.
What is the chemical composition of SA387 Gr 12 Cl 1?
The composition includes C 0.05-0.17%, Mn 0.40-0.65%, P ≤0.025%, S ≤0.025%, Si 0.50-0.80%, Cr 1.00-1.50%, Mo 0.45-0.65%, tested per ASME SA-350. This alloyed formula ensures creep resistance with CE ≤0.45 (AWS D1.1). SHH STEEL provides MTCs with full analysis for traceability.
Is SA387 Gr 12 Cl 1 weldable?
Yes, SA387 Gr 12 Cl 1 is highly weldable with low carbon (0.05-0.17%) and preheating at 150-200°C for >25mm thicknesses. Use E7018 filler (AWS A5.1) for 90% joint efficiency per ASME Section IX. PWHT at 620-650°C reduces stress, validated by bend tests per ASTM E190.
What is the density of SA387 Gr 12 Cl 1?
he density is 7.85 g/cm³, standard for alloy steel, aiding weight calculations in vessel design. Hardness is 150-220 HB (ASME SA-18), balancing wear resistance for high-temperature use.
What is the equivalent of ASME SA387 Gr 12 Cl 1 in EN standards?
The closest EN equivalent is 10CrMo9-10 (EN 10028-2), with 480-630 MPa tensile and 280 MPa yield, suitable for EU boilers. SHH STEEL provides dual-certified plates for seamless transitions.
What is the maximum thickness for SA387 Gr 12 Cl 1?
Standard thickness is 100mm, with custom options up to 300mm available. Normalized at 900-950°C per ASME SA-20, these plates are ideal for high-temperature vessels, with ultrasonic testing per ASME SA-578 ensuring no laminations for structural integrity.

Conclusion

SHH STEEL’s ASME SA387 Gr 12 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.

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