ASME SA-542/SA-542M
SA542 Type D Category 2 Pressure Vessel Steel Plate Product-Performance
Technical Datasheet
Chromium-molybdenum-vanadium (Cr-Mo-V) quenched and tempered pressure vessel steel plate, with very high strength and excellent toughness. Suitable for the most demanding pressure vessel applications in petrochemical and power generation industries.
1. SA542 Type D Category 2 Material Identification & ASTM ASME Standards
Standards
- ASTM A542 / ASME SA542
- ASTM A20/A20M (General Requirements)
- ASME BPVC Section II Part A
Alloy Type
2.25Cr-1Mo-V
Grade Classification
- SA542 Type D Class 4a (2.25Cr-1Mo-V, lower strength)
- SA542 Type D Category 2 (2.25Cr-1Mo-V, very high strength) ← This Spec
- SA542 Type D Category 3 (2.25Cr-1Mo-V, high strength)
- SA542 Type E (2.75Cr-1Mo-V)
- SA542 Type E Class 1 (2.75Cr-1Mo-V)
2. SA542 Type D Category 2 Chemical Composition & Ladle Analysis Requirements
2.1 SA542 Type D Category 2 Chemical Composition Limits
| Element | Smelting Analysis | Finished Product Analysis |
|---|---|---|
| C | 0.11-0.15 | 0.09-0.18 |
| Mn | 0.30-0.60 | 0.25-0.66 |
| Si, ≤ | 0.10 | 0.10 |
| S, ≤ | 0.010 | 0.010 |
| P, ≤ | 0.015 | 0.015 |
| Cr | 2.00-2.50 | 1.08-2.62 |
| Mo | 0.90-1.10 | 0.85-1.15 |
| Ni, ≤ | 0.25 | 0.28 |
| V | 0.25-0.35 | 0.23-0.37 |
| B, ≤ | 0.0020 | NA |
| Ti, ≤ | 0.030 | 0.035 |
| Cu, ≤ | 0.20 | 0.23 |
| Nb, ≤ | 0.07 | 0.08 |
| Ca, ≤ | 0.015 | 0.020 |
| Zr | ... | |
| Others | ... | |
Carbon Equivalent (CE)
CE = C + Mn/6 + (Cr+Mo+V)/5 + (Ni+Cu)/15
Typical value: 0.65-0.85 (depending on actual composition)
Note: Cr-Mo-V steel requires controlled welding procedures due to high hardenability; low hydrogen practice is mandatory. Boron is added for hardenability but is not applicable to finished product analysis.
3. SA542 Type D Category 2 Mechanical Properties & Tensile Strength Specification
3.1 SA542 Type D Category 2 Tensile Properties
| Property | Standard Value | Test Method | Remarks |
|---|---|---|---|
| Tensile Strength Rm | 795-930 MPa | ASTM A370 | Transverse specimen |
| Yield Strength ReH | >=690 MPa | ASTM A370 | Upper yield strength |
| Elongation A (2in./50mm) | >=13% | ASTM A370 | Per A20/A20M |
| Charpy Impact KV₂ | ... | — | By agreement |
3.2 Charpy Impact Test Requirements for SA542 Type D Category 2
Standard Grade
Impact testing not required by standard
Very High Strength ServiceLow Temperature Service
- Impact testing by agreement
- Cr-Mo-V provides good toughness
- Typical test temperature: 0°C to -20°C
3.3 SA542 Type D Category 2 Hardness & Brinell Hardness Limits
- As-supplied condition (quenched + tempered): Typically ≤280 HBW
- NACE service environment: Weld & HAZ ≤250 HV10
4. SA542 Type D Category 2 Quenched + Tempered: Heat Treatment Guide
1
As-Rolled (AR)
Not applicable for SA542
High hardenability requires Q+T
→
2
Quenched + Tempered (Q+T)
Austenitizing: 900-960°C
Quench: Water or Oil
Tempering: 620-700°C
→
3
Simulated PWHT (SPWHT)
620-700°C × 2-4h
For property verification
Critical Control Points:
- SA542 must be supplied in quenched + tempered condition
- Austenitizing temperature: 900-960°C, quench in water or oil
- Tempering temperature: 620-700°C, air cool
- Tempering temperature must be carefully controlled to achieve required strength and toughness balance
5. SA542 Type D Category 2 Welding Procedure Specification (WPS/PQR)
5.1 SA542 Type D Category 2 Welding Procedure Specification WPS
SMAW (Shielded Metal Arc) SAW (Submerged Arc) GTAW (Gas Tungsten Arc) FCAW (Flux Cored)
5.2 SA542 Type D Category 2 Preheat & Interpass Temperature Chart
| Thickness Range | Min Preheat Temp | Recommended Preheat | Max Interpass Temp |
|---|---|---|---|
| <=13mm | 150°C | 150-200°C | 250-300°C |
| >13-38mm | 150°C | 150-250°C | |
| >38mm | 150°C | 200-250°C |
5.3 Recommended Welding Consumables for SA542 Type D Category 2
| Process | AWS Classification | Strength Match | Hydrogen Control |
|---|---|---|---|
| SMAW | E11018-M, E11018-M-H4 | 110 ksi | Low Hydrogen (H4) |
| GTAW | ER110S-G | 110 ksi | Shielding: Ar |
| FCAW | E110T5-K4 | 110 ksi | Self/ Gas Shielded |
| SAW | F11A4-EG, F11P4-EG | 110 ksi | Flux bake 300°C*2h |
5.4 SA542 Type D Category 2 PWHT Requirements & Post Weld Heat Treatment
Temperature Range 620-700°C
Holding Time 1h/25mm thickness (min 30min)
Heating Rate <=150°C/h
Cooling Rate <=150°C/h (to 300°C)
PWHT Notes:
- PWHT is mandatory for SA542 steel to achieve required mechanical properties
- Tempering temperature must be carefully controlled to avoid over-tempering
- Cooling rate should be controlled to prevent residual stresses
6. SA542 Type D Category 2 High Temperature Service & Creep Resistance
6.1 SA542 Type D Category 2 High Temperature Properties
High Temperature Capability
- Very high strength at elevated temperatures
- Good hydrogen resistance at elevated temperatures
- Good oxidation resistance (2.25% Cr)
- High thermal conductivity
Applications
- Ultra-high-strength hydroprocessing reactors
- Hydrocracking equipment
- High-temperature heat exchangers
- Petrochemical pressure vessels
6.2 SA542 Type D Category 2 Creep Rupture Properties
Grade SA542 Type D Category 2 provides excellent creep rupture strength at elevated temperatures:
- At 450°C: 100,000 hour creep rupture strength ~200 MPa
- At 500°C: 100,000 hour creep rupture strength ~150 MPa
- At 550°C: 100,000 hour creep rupture strength ~90 MPa
- At 580°C: 100,000 hour creep rupture strength ~60 MPa
7. SA542 Type D Category 2 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. SA542 Type D Category 2 Physical Properties & Thermal Conductivity
Density
7.80
g/cm3 (20°C)
Melting Point
~1510
°C
Thermal Conductivity
35-40
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. SA542 Type D Category 2 Dimensions & Thickness Tolerance ASTM A20
9.1 Available Dimensions
Thickness 6-200 mm (Standard 6-100mm)
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. SA542 Type D Category 2 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
11. SA542 Type D Category 2 Equivalent Grades: Cr-Mo-V Steel Comparison
| Grade | Standard | Country | Yield MPa |
Tensile MPa |
Cr Content % |
Key Differences |
|---|---|---|---|---|---|---|
| SA542 Type D Category 2 | ASME | USA | >=690 | 795-930 | 2.00-2.50 | ASME BPVC, very high strength 2.25Cr-1Mo-V steel |
| SA542 Type D Category 3 | ASME | USA | >=515 | 655-795 | 2.00-2.50 | Lower strength, same composition |
| SA542 Type E Category 2 | ASME | USA | >=690 | 795-930 | 2.75-3.25 | Higher Cr content, similar strength |
| SA387 Gr.22 | ASME | USA | >=310 | 515-690 | 2.00-2.50 | Similar Cr content, no V, much lower strength |
High Temperature Service Notes:
- SA542 Type D Category 2: Very high strength, yield ≥690 MPa
- SA542 Type D Category 3: High strength, yield ≥515 MPa
- SA542 Type E Category 2: Higher Cr content, similar strength
- SA387 Gr.22: Similar Cr content, no V, much lower strength
- Cr-Mo-V steel requires controlled heat treatment and welding procedures
Warning: Equivalent grades are approximate. Project-specific Gap Analysis and PQR qualification required. Yield strength and creep rupture strength are critical for high-temperature pressure vessel design.
12. SA542 Type D Category 2 Design Considerations & Fabrication Guidelines
Design Considerations
- Very high strength: SA542 Type D Category 2 suitable for the most demanding pressure vessel applications
- Hydrogen service: Good resistance to hydrogen attack at elevated temperatures
- 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: Limited formability due to very high strength; bend radius recommended >=5t (t=plate thickness)
- Hot forming: Forming temperature 900-960°C, re-quenching and tempering required after forming
- Grinding: Defect removal depth not to exceed 7% of plate thickness, PT/MT verification required
Common Failure Mode Prevention
- Type IV cracking: Avoid prolonged PWHT in 750-850°C range
- Hydrogen-induced cold cracking: Strict low-hydrogen practice, control diffusible hydrogen <=5 mL/100g
- Creep damage: Regular inspection for creep damage in high-temperature service
- Temper embrittlement: Avoid prolonged exposure to 350-550°C range