ASTM SA225 Grade D Pressure Vessel Steel Plate Chemical Composition & Mechanical Properties
Chinese-made American Standard Steel Plate Technical Data
Manganese-vanadium-nickel alloy steel plate intended primarily for welded layered pressure vessels. Grade D provides a balanced combination of strength and toughness for moderate-temperature pressure equipment.
1. ASTM SA225 Grade D Material Identification & Standards
Standards
- ASTM A225 / A225M
- ASME SA225 / SA225M
- ASTM A20/A20M (General Requirements)
- ASME BPVC Section II Part A
Alloy Type
Mn-V-Ni
Manganese-Vanadium-Nickel Steel
Grade Classification
- ASTM SA225 Grade D ← This Spec
- SA225 Grade C (higher strength, 725-930 MPa)
Note: ASTM A225 Grade D is a manganese-vanadium-nickel alloy steel plate intended primarily for welded layered pressure vessels [citation:1][citation:2]. The steel shall be killed and shall conform to fine austenitic grain size requirements [citation:1]. Current mill practice normally limits Grade D to 6 in. [150 mm] maximum thickness [citation:5].
2. ASTM SA225 Grade D Chemical Composition & Ladle Analysis Requirements
2.1 ASTM SA225 Grade D Chemical Composition Limits
| Element | Smelting Analysis | Finished Product Analysis |
|---|---|---|
| C, ≤ | 0.20 | |
| Mn, ≤ | 1.70 | 1.84 |
| Si | 0.10-0.50 | 0.08-0.56 |
| S, ≤ | 0.035 | |
| P, ≤ | 0.035 | |
| Ni | 0.40-0.70 | 0.37-0.73 |
| V | 0.10-0.18 | 0.08-0.20 |
| Cr | ... | |
| Mo | ... | |
Alloy Design Notes
SA225 Grade D is a Mn-V-Ni steel. The vanadium addition provides precipitation strengthening, while nickel improves toughness. This grade is primarily intended for welded layered pressure vessels [citation:1].
3. ASTM SA225 Grade D Mechanical Properties & Tensile Strength Specification
3.1 ASTM SA225 Grade D Tensile Properties
| Property | Thickness ≤75mm | Thickness >75mm | Test Method |
|---|---|---|---|
| Tensile Strength Rm | 550-725 MPa | 515-690 MPa | ASTM A370 |
| Yield Strength ReH | >=380 MPa | >=380 MPa | ASTM A370 |
| Elongation A (8in./200mm) | >=19% | >=19% | ASTM A370 |
| Elongation A (2in./50mm) | >=17% | ASTM A370 | |
| Charpy Impact KV₂ | By agreement | ASTM A370 | |
3.2 Charpy Impact Test Requirements for ASTM SA225 Grade D
Impact Testing
Not required by standard for Grade D
May be specified by agreement
By AgreementService Conditions
- Moderate-temperature pressure service
- Layered pressure vessel construction
- Impact test temperature by agreement
3.3 ASTM SA225 Grade D Hardness Limits
- As-supplied condition: Typically ≤250 HBW
- NACE service environment: Weld & HAZ hardness control required
4. ASTM SA225 Grade D Heat Treatment Guide
The plates shall undergo heat treatment per ASTM A225 [citation:1]. Specific heat treatment parameters shall be agreed upon between manufacturer and purchaser.
- Steel shall be killed and conform to fine austenitic grain size requirements [citation:1]
- Plates shall undergo heat treatment as specified [citation:1]
- Maximum thickness limited by capacity to meet mechanical properties [citation:1]
- Current mill practice limits Grade D to 6 in. [150 mm] maximum [citation:5]
5. ASTM SA225 Grade D Welding Procedure Specification (WPS/PQR)
5.1 ASTM SA225 Grade D Welding Procedure Specification WPS
5.2 ASTM SA225 Grade D Preheat & Interpass Temperature Chart
| Thickness Range | Min Preheat Temp | Recommended Preheat | Max Interpass Temp |
|---|---|---|---|
| <=25mm | 100°C | 100-150°C | 200-250°C |
| >25mm | 150°C | 150-200°C |
5.3 Recommended Welding Consumables for ASTM SA225 Grade D
| Process | AWS Classification | Strength Match | Hydrogen Control |
|---|---|---|---|
| SMAW | E8018-B2, E8018-B2H4 | 80 ksi | Low Hydrogen (H4) |
| GTAW | ER80S-B2 | 80 ksi | Shielding: Ar |
| FCAW | E81T1-B2 | 80 ksi | Self/ Gas Shielded |
| SAW | F8A2-EB2, F8P2-EB2 | 80 ksi | Flux bake 300°C*2h |
- Use low hydrogen welding practice for Mn-V-Ni steel
- Preheat required to prevent cold cracking
- Control heat input to maintain base metal properties
- PWHT typically required for pressure vessel service
6. ASTM SA225 Grade D Pressure Vessel Service & Applications
6.1 ASTM SA225 Grade D Service Capability
Service Characteristics
- Moderate strength, good toughness balance
- Mn-V-Ni composition for pressure vessel service
- Suitable for layered vessel construction
- Vanadium provides precipitation strengthening
Typical Applications
- Welded layered pressure vessels [citation:1]
- Moderate-temperature pressure equipment
- Process industry vessels
- Storage tanks and reactors
6.2 ASTM SA225 Grade D Thickness Capability
Maximum thickness for Grade D: Limited only by capacity to meet mechanical properties [citation:1]
Current mill practice normally limits Grade D to 6 in. [150 mm] maximum [citation:5].
7. ASTM SA225 Grade D Inspection & NDT Testing Methods
7.1 Non-Destructive Testing
7.2 Specimen Orientation & Location
Preferred for tensile
Reflects transverse properties
Per ASTM A370
Standard plate specimen
By agreement
If required
8. ASTM SA225 Grade D Physical Properties
Density
7.67-7.86
g/cm3 [citation:7]
Elastic Modulus
190-210
GPa [citation:7]
Poisson's Ratio
0.27-0.30
[citation:7]
9. ASTM SA225 Grade D Dimensions & Thickness Tolerance
9.1 Available Dimensions
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. ASTM SA225 Grade D 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 if required)
- ✓Heat treatment records (temperature-time curves)
- ✓NDT reports (UT/MT etc.)
- ✓Dimensional inspection records
11. ASTM SA225 Grade D Equivalent Grades: Mn-V-Ni Steel Comparison
| Standard | Grade | Country | Yield MPa | Tensile MPa | Key Characteristics |
|---|---|---|---|---|---|
| ASTM A225 | Grade D | USA | ≥380 | 550-725 | Mn-V-Ni, layered pressure vessels [citation:1] |
| ASME SA225 | Grade D | USA | ≥380 | 550-725 | ASME equivalent to A225 Gr.D |
Warning: Equivalent grades are approximate. Project-specific Gap Analysis and PQR qualification required.
12. ASTM SA225 Grade D Design Considerations & Fabrication Guidelines
Design Considerations
- Moderate strength: SA225 Grade D provides yield strength of 380 MPa
- Thickness capability: Maximum limited by capacity to meet mechanical properties [citation:1]
- Application: Primarily for welded layered pressure vessels [citation:1]
- Steel shall be killed and fine grain practice [citation:1]
Fabrication Considerations
- Welding: Low hydrogen practice mandatory; preheat 100-150°C
- PWHT: Typically required for pressure vessel service
- Heat treatment: Plates shall undergo heat treatment [citation:1]
- Machining: Standard procedures for alloy steel
Common Failure Mode Prevention
- Hydrogen-induced cold cracking: Strict low-hydrogen practice, preheat
- HAZ softening: Control heat input during welding
- Lamellar tearing: Consider through-thickness properties for critical joints