ASME SA-203/SA-203M
SA203 Grade E Pressure Vessel Steel Plate Product-Performance
Technical Datasheet
Nickel-alloyed (3.25-3.75% Ni) pressure vessel steel plate, supplied in normalized condition, with excellent low-temperature notch toughness and weldability. Suitable for welded pressure vessels, boilers, and storage tanks in low temperature service.
1. SA203 Grade E Material Identification & ASTM ASME Standards
Standards
- ASTM A203 / ASME SA203
- ASTM A20/A20M (General Requirements)
- ASME BPVC Section II Part A
Nickel Content
3.25-3.75% Ni
Grade Classification
- Grade A (2.25% Ni)
- Grade B (2.25% Ni)
- Grade D (3.50% Ni)
- Grade E (3.50% Ni) ← This Spec
- Grade F (3.50% Ni)
2. SA203 Gr.E Chemical Composition & Ladle Analysis Requirements
2.1 SA203 Grade E Chemical Composition Limits by Thickness
| Element | Analysis Type | ≤2in. (50mm) | >2-4in. (50-100mm) | >4in. (100mm) |
|---|---|---|---|---|
| C, ≤① | Ladle/Product | 0.20 | 0.23 | ... |
| Mn, ≤ | Smelting | 0.70 | 0.80 | — |
| Smelting | ≤50mm | ≤50mm | — | |
| Product | 0.78 | 0.88 | — | |
| Product | ≤50mm | ≤50mm | — | |
| P, ≤① | Ladle/Product | ≤0.025 | ||
| S, ≤① | Ladle/Product | ≤0.025 | ||
| Si | Smelting | 0.15-0.40 | ||
| Product | 0.13-0.45 | |||
| Ni | Smelting | 3.25-3.75 | ||
| Product | 3.18-3.82 | |||
Carbon Equivalent (CE)
CE = C + Mn/6 + (Cr+Mo+V)/5 + (Ni+Cu)/15
Typical value: 0.42-0.52 (depending on actual composition)
Note: Nickel addition improves low-temperature toughness but may slightly increase hardenability
- 1 Both smelting analysis and finished product analysis are applicable
- 2 Manganese limits apply to both smelting (0.70 max ≤50mm, 0.80 max >50-100mm) and product analysis (0.78 max ≤50mm, 0.88 max >50-100mm)
- 3 Nickel is the primary alloying element, providing excellent low-temperature toughness
3. SA203 Grade E Mechanical Properties & Tensile Strength Specification
3.1 SA203 Grade E Tensile Properties at Room Temperature
| Property | Standard Value | Test Method | Remarks |
|---|---|---|---|
| Tensile Strength Rm | 485-620 MPa (≤50mm) 485-620 MPa (>50mm) |
ASTM A370 | Transverse specimen |
| Yield Strength ReL or Rp0.2 | >=275 MPa (≤50mm) >=275 MPa (>50mm) |
0.2% Offset Method | Or 0.5% Extension |
| Elongation A | >=17% (200mm GL) >=21% (50mm GL) |
ASTM A370 | Per A20/A20M |
| Reduction of Area Z | — | — | Not mandatory |
3.2 Charpy Impact Test Temperature Requirements for SA203 Gr.E
Standard Grade (Non-Low Temp)
Impact testing not required by standard
General ServiceLow Temperature Grade
- Nickel content (3.25-3.75%) provides excellent low-temp toughness
- Test Temp: -101°C (-150°F) typical for LNG service
- Absorbed Energy: By agreement
3.3 SA203 Gr.E Hardness & Brinell Hardness Limits
- As-supplied condition: Typically ≤200 HBW
- NACE service environment: Weld & HAZ ≤250 HV10
4. SA203 Gr.E Normalized: Heat Treatment Guide
1
As-Rolled (AR)
Not recommended for nickel steel
Low-temperature toughness not guaranteed
→
2
Normalized (N)
Heating: 870-900°C
Holding: 1-2 min/mm
Cooling: Air
→
3
Simulated PWHT (SPWHT)
595-620°C × 2-4h
For property verification
Critical Control Points:
- Nickel steel requires normalizing to develop optimal low-temperature toughness
- Normalizing temperature: 870-900°C, hold 1-2 min/mm, air cool
- Grain size after normalizing: >=ASTM 5 (fine grain steel)
- Thickness >50mm: Normalizing mandatory to ensure toughness
5. SA203 Gr.E Welding Procedure Specification (WPS/PQR)
5.1 SA203 Gr.E Welding Procedure Specification WPS
SMAW (Shielded Metal Arc) SAW (Submerged Arc) GMAW (Gas Metal Arc) FCAW (Flux Cored) GTAW (Gas Tungsten Arc)
5.2 SA203 Gr.E Preheat & Interpass Temperature Chart
| Thickness Range | Min Preheat Temp | Recommended Preheat | Max Interpass Temp |
|---|---|---|---|
| <=13mm | 10°C (Ambient) | 100-150°C | 250-315°C |
| >13-38mm | 100°C | 100-150°C | |
| >38mm | 110°C | 150-200°C |
5.3 Recommended Welding Consumables for SA203 Grade E
| Process | AWS Classification | Strength Match | Hydrogen Control |
|---|---|---|---|
| SMAW | E8018-C3, E8018-Ni3 | 80 ksi | Low Hydrogen (H4) |
| GMAW | ER80S-Ni3 | 80 ksi | Shielding: Ar+CO2 |
| FCAW | E81T1-Ni3 | 80 ksi | Self/ Gas Shielded |
| SAW | F8A4-ENi3, F8P4-ENi3 | 80 ksi | Flux bake 300°C*2h |
5.4 SA203 Gr.E PWHT Requirements & Post Weld Heat Treatment
Temperature Range 593-649°C (1100-1200°F)
Holding Time 1h/25mm thickness (min 15min)
Heating Rate <=220°C/h (<=300mm thick)
Cooling Rate <=260°C/h (Air cool)
PWHT Exemption Conditions (ASME VIII-1 UCS-79):
- Base metal thickness <=38mm and preheat >=95°C
- Weld thickness <=32mm (fillet weld throat <=28mm)
- Temper bead technique qualified by PQR
6. SA203 Gr.E HIC NACE MR0175 & Low Temperature Service Requirements
6.1 SA203 Gr.E HIC Test NACE TM0284 Solution A for Wet H2S Service
HIC Test (Hydrogen Induced Cracking)
- Test Standard: NACE TM0284 Solution A
- Acceptance Criteria:
- CLR (Crack Length Ratio) <=5%
- CTR (Crack Thickness Ratio) <=1.5%
- CSR (Crack Sensitivity Ratio) <=0.5%
- Sampling: 1/4T and 1/2T of plate thickness
SSC Test (Sulfide Stress Cracking)
- Test Standard: NACE TM0177 Method A
- Stress Level: 80% AYS (Actual Yield Strength)
- Test Duration: 720 hours
- Acceptance: No cracking
6.2 SA203 Gr.E Low Temperature Service
For equipment with design temperature below -29°C:
- Low temperature impact testing mandatory (-101°C typical for LNG service)
- Nickel content (3.25-3.75%) provides excellent toughness at cryogenic temperatures
- Normalized condition required for optimal low-temperature properties
7. SA203 Grade E Inspection & NDT Testing Methods
7.1 Non-Destructive Testing
UT ASTM A578/A578M Level C (Most Strict)
MT ASTM A275/A275M Surface Crack Detection
PT ASTM A165 Surface Open Defects
RT ASME V Article 2 Weld Internal Quality
7.2 Specimen Orientation & Location
Transverse (T)
Preferred for tensile & impact
Reflects transverse properties
Longitudinal (L)
Only when width insufficient
Higher strength, lower toughness
Thickness Position
1/4T or 1/2T
Represents worst location
7.3 Retest Procedures
- Tensile failure: Double retest from same plate; plate acceptable if both pass
- Impact failure: Additional 3 sets (9 specimens) from same plate; average must meet requirement with individual values >=70% of specified
- UT failure: Defect removal and re-inspection or rejection
8. SA203 Gr.E Physical Properties & Thermal Conductivity
Density
7.85
g/cm3 (20°C)
Melting Point
~1510
°C
Thermal Conductivity
40-45
W/(m*K) (20-100°C)
Linear Expansion
11.5
*10-6/°C (20-300°C)
Specific Heat
460-500
J/(kg*K) (20°C)
Elastic Modulus
200-210
GPa (20°C)
9. SA203 Grade E Dimensions & Thickness Tolerance ASTM A20
9.1 Available Dimensions
Thickness 6-400 mm (Standard 6-200mm)
Width 1500-4350 mm
Length 3000-27000 mm
Unit Weight Max 60 MT
9.2 Thickness Tolerances (ASTM A20)
| Nominal Thickness | Class A (Unrestricted) | Class B (Restricted) |
|---|---|---|
| 6-25mm | +1.20mm, -0.30mm | +/-0.60mm |
| >25-50mm | +1.50mm, -0.30mm | +/-0.80mm |
| >50-100mm | +2.40mm, -0.30mm | +/-1.20mm |
10. SA203 Gr.E Mill Test Certificate & EN 10204 3.2 Documentation
EN 10204 3.1
Manufacturer Test Certificate
Based on non-specific inspection
EN 10204 3.2
Third Party Inspection Certificate
Witnessed by customer or third party
ASME Data Report
Form CM-1
For ASME stamped equipment
Mill Test Certificate must include:
- ✓Heat number, plate number, batch traceability
- ✓Chemical composition (ladle + product analysis)
- ✓Mechanical properties (tensile, impact)
- ✓Heat treatment records (temperature-time curves)
- ✓NDT reports (UT/MT etc.)
- ✓Dimensional inspection records
- ✓HIC/SSC test reports (if applicable)
11. SA203 Grade E Equivalent Grades: 12Ni14 3.5Ni Steel Comparison
| Grade | Standard | Country | Yield MPa |
Tensile MPa |
Ni Content % |
Key Differences |
|---|---|---|---|---|---|---|
| SA203 Gr.E | ASME | USA | >=275 | 485-620 | 3.25-3.75 | ASME BPVC, 3.5% Ni steel for low-temp service |
| SA203 Gr.D | ASME | USA | >=275 | 485-620 | 3.25-3.75 | Similar to Gr.E with different impact requirements |
| 12Ni14 | EN 10028-4 | Europe | >=390 | 530-710 | 3.25-3.75 | Higher strength, European low-temp standard |
| SL3N | JIS G 3126 | Japan | >=275 | 480-620 | 3.25-3.75 | Japanese cryogenic pressure vessel standard |
| 09MnNiDR | GB/T 3531 | China | >=320 | 440-570 | 0.30-0.80 | Chinese low-temp steel with lower Ni content |
Impact Test Notes:
- SA203 Gr.E: Impact testing at low temperature by agreement, typically -101°C for LNG service
- 12Ni14: Impact tested at -110°C, 27J minimum typical
- 09MnNiDR: Impact tested at -70°C, 34J minimum
- Nickel content directly correlates with low-temperature toughness capability
Warning: Equivalent grades are approximate. Project-specific Gap Analysis and PQR qualification required. Yield strength and impact energy are critical for pressure vessel design.
12. SA203 Gr.E Design Considerations & Fabrication Guidelines
Design Considerations
- High temperature creep: SA203 Gr.E limited to low-temperature service (typically <=200°C)
- Low temperature brittle fracture: Nickel addition provides excellent toughness at cryogenic temperatures (down to -101°C)
- Thickness effect: As plate thickness increases, strength and toughness decrease; allowable design stress must be interpolated per ASME II-D Table 1A
Fabrication Considerations
- Cold forming: Bend radius recommended >=3t (t=plate thickness) to avoid surface cracking
- Hot forming: Forming temperature 870-900°C, re-normalization required after forming
- Grinding: Defect removal depth not to exceed 7% of plate thickness, PT/MT verification required
Common Failure Mode Prevention
- Reheat cracking: Avoid prolonged PWHT in 550-600°C range
- Hydrogen-induced cold cracking: Strict low-hydrogen practice, control diffusible hydrogen <=5 mL/100g
- Temper embrittlement: Step cooling test verification (for elevated temperature service)