ASME SA-387/SA-387M

SA387 Grade 2 Pressure Vessel Steel Plate Product-Performance

Technical Datasheet

Chromium-molybdenum (0.5Cr-0.5Mo) pressure vessel steel plate, supplied in annealed or normalized and tempered condition, with good high-temperature strength and creep resistance. Suitable for elevated temperature service in petrochemical and power generation applications.

1. SA387 Grade 2 Material Identification & ASTM ASME Standards

Standards

  • ASTM A387 / ASME SA387
  • ASTM A20/A20M (General Requirements)
  • ASME BPVC Section II Part A

Alloy Type

0.5Cr-0.5Mo

Grade Classification

  • SA387 Gr.2 (0.5Cr-0.5Mo) ← This Spec
  • SA387 Gr.5 (5Cr-0.5Mo)
  • SA387 Gr.9 (9Cr-1Mo)
  • SA387 Gr.11 (1.25Cr-0.5Mo)
  • SA387 Gr.12 (1Cr-0.5Mo)
  • SA387 Gr.21 (3Cr-1Mo)
  • SA387 Gr.22 (2.25Cr-1Mo)
  • SA387 Gr.91 (9Cr-1Mo-V)

2. SA387 Gr.2 Chemical Composition & Ladle Analysis Requirements

2.1 SA387 Grade 2 Chemical Composition Limits

Table 2.1: SA387 Gr.2 Chemical Composition Requirements (ASTM A387/ASME SA387 Mass Percent)
Element Smelting Analysis Finished Product Analysis
C 0.05-0.21① 0.04-0.21①
Mn 0.55-0.80 0.50-0.88
P, ≤ 0.025 0.025
S, ≤ 0.025 0.025
Si 0.15-0.40 0.13-0.45
Cr 0.50-0.80 0.46-0.85
Mo 0.45-0.60 0.40-0.65
Ni ...
V ...
Nb② ...
B, ≤③ ...
N ...
N/Al ...
Al, ≤③ ...
Ti, ≤③ ...
Zr, ≤③ ...
W, ≤③ ...
Cu, ≤③ ...
Sb, ≤③ ...
As, ≤③ ...
Sn, ≤③ ...

Carbon Equivalent (CE)

CE = C + Mn/6 + (Cr+Mo+V)/5 + (Ni+Cu)/15

Typical value: 0.45-0.70 (depending on actual composition)

Note: 0.5Cr-0.5Mo steel requires controlled welding procedures due to moderate hardenability

  • A For steel plates with a thickness greater than 5 inches (125 mm), the carbon content in the finished product analysis should not exceed 0.17%
  • B Cb and Nb are interchangeable and commonly used names for the same element, and both names are applicable to the ASTM "A101" standard
  • C Both smelting analysis and finished product analysis are applicable

3. SA387 Grade 2 Mechanical Properties & Tensile Strength Specification

3.1 SA387 Grade 2 Tensile Properties (Class I Steel Plates)

Property Standard Value Test Method Remarks
Tensile Strength Rm 380-550 MPa ASTM A370 Transverse specimen
Yield Strength ReL or Rp0.2 >=230 MPa 0.2% Offset Method Or 0.5% Extension
Elongation A (8in./200mm) >=18% ASTM A370 Per A20/A20M
Elongation A (2in./50mm) >=22% ASTM A370 Per A20/A20M
Reduction of Area Z ... — Not specified

3.2 SA387 Grade 2 Tensile Properties (Class II Steel Plates)

Property Standard Value Test Method Remarks
Tensile Strength Rm 485-620 MPa ASTM A370 Transverse specimen
Yield Strength ReL or Rp0.2 >=310 MPa 0.2% Offset Method Or 0.5% Extension
Elongation A (8in./200mm) >=18% ASTM A370 Per A20/A20M
Elongation A (2in./50mm) >=22% ASTM A370 Per A20/A20M
Reduction of Area Z ... — Not specified

3.3 Charpy Impact Test Requirements for SA387 Gr.2

Standard Grade

Impact testing not required by standard

High Temperature Service

High Temperature Service

  • 0.5Cr-0.5Mo provides moderate creep resistance
  • Service temperature: up to 500°C
  • Impact testing: By agreement
By Agreement

3.4 SA387 Gr.2 Hardness & Brinell Hardness Limits

  • As-supplied condition (annealed or N+T): Typically ≤225 HBW
  • NACE service environment: Weld & HAZ ≤250 HV10

4. SA387 Gr.2 Annealed or Normalized + Tempered: Heat Treatment Guide

1

As-Rolled (AR)

Not applicable for Grade 2

Moderate hardenability requires heat treatment

→
2

Annealed or Normalized + Tempered

Annealing: 855-900°C

Or N: 900-950°C + T: 650-720°C

Cooling: Furnace or Air

→
3

Simulated PWHT (SPWHT)

650-720°C × 2-4h

For property verification

Critical Control Points:
  • Grade 2 can be supplied in annealed or normalized + tempered condition
  • Annealing temperature: 855-900°C, furnace cool
  • Normalizing + tempering: 900-950°C + 650-720°C
  • Cooling rate after normalizing: Air cool or accelerated cooling as required

5. SA387 Gr.2 Welding Procedure Specification (WPS/PQR)

5.1 SA387 Gr.2 Welding Procedure Specification WPS

SMAW (Shielded Metal Arc) SAW (Submerged Arc) GTAW (Gas Tungsten Arc) FCAW (Flux Cored)

5.2 SA387 Gr.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 SA387 Grade 2

Process AWS Classification Strength Match Hydrogen Control
SMAW E8015-B2, E8015-B2H4 80 ksi Low Hydrogen (H4)
GTAW ER80S-B2 80 ksi Shielding: Ar
FCAW E81T1-B2 80 ksi Self/ Gas Shielded
SAW F8A2-B2, F8P2-B2 80 ksi Flux bake 300°C*2h

5.4 SA387 Gr.2 PWHT Requirements & Post Weld Heat Treatment

Temperature Range 650-720°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 Grade 2 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. SA387 Gr.2 High Temperature Service & Creep Resistance

6.1 SA387 Gr.2 High Temperature Properties

High Temperature Capability

  • Moderate creep resistance up to 500°C
  • Good hydrogen resistance at elevated temperatures
  • Moderate oxidation resistance (0.5% Cr)
  • High thermal conductivity

Applications

  • Hydroprocessing reactors
  • Hydrocracking equipment
  • High-temperature heat exchangers
  • Petrochemical pressure vessels

6.2 SA387 Gr.2 Creep Rupture Properties

Grade 2 provides moderate creep rupture strength at elevated temperatures:

  • At 450°C: 100,000 hour creep rupture strength ~90 MPa
  • At 500°C: 100,000 hour creep rupture strength ~60 MPa
  • At 550°C: 100,000 hour creep rupture strength ~35 MPa

7. SA387 Grade 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. SA387 Gr.2 Physical Properties & Thermal Conductivity

Density

7.80

g/cm3 (20°C)

Melting Point

~1510

°C

Thermal Conductivity

38-42

W/(m*K) (20-100°C)

Linear Expansion

11.0

*10-6/°C (20-300°C)

Specific Heat

460-500

J/(kg*K) (20°C)

Elastic Modulus

200-210

GPa (20°C)

9. SA387 Grade 2 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. SA387 Gr.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
  • ✓Creep test reports (if applicable)

11. SA387 Grade 2 Equivalent Grades: 0.5Cr-0.5Mo Comparison

Grade Standard Country Yield
MPa		 Tensile
MPa		 Cr Content
%		 Key Differences
SA387 Gr.2 ASME USA >=230 (CI)
>=310 (CII)		 380-550 (CI)
485-620 (CII)		 0.50-0.80 ASME BPVC, 0.5Cr-0.5Mo high temp steel
SA387 Gr.11 ASME USA >=240 (CI)
>=310 (CII)		 415-585 (CI)
515-690 (CII)		 1.00-1.50 Higher Cr content, better high-temp capability
13CrMo4-5 EN 10028-2 Europe >=275 440-590 0.70-1.15 European equivalent, higher Cr than Gr.2
SA387 Gr.12 ASME USA >=230 (CI)
>=275 (CII)		 380-550 (CI)
450-585 (CII)		 0.80-1.15 Higher Cr content, slightly better high-temp capability than Gr.2
High Temperature Service Notes:
  • SA387 Gr.2: Maximum service temperature up to 500°C, moderate creep resistance
  • SA387 Gr.11: Higher Cr content for better high-temp capability up to 550°C
  • SA387 Gr.12: 1Cr-0.5Mo steel, intermediate between Gr.2 and Gr.11
  • 13CrMo4-5: European equivalent with higher Cr and Mo content
  • 0.5Cr-0.5Mo 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. SA387 Gr.2 Design Considerations & Fabrication Guidelines

Design Considerations

  • High temperature creep: SA387 Gr.2 suitable for long-term service up to 500°C
  • 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: Bend radius recommended >=4t (t=plate thickness) to avoid surface cracking
  • Hot forming: Forming temperature 855-900°C, re-annealing 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

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