SA 387 Grade 5 Class 1 is a carbon-manganese steel plate specification developed for use in welded pressure vessels where improved notch toughness is required. It is part of the ASME Boiler and Pressure Vessel Code, specifically under Section II, Part A, and is intended for service at moderate to elevated temperatures.
This grade provides a good combination of strength and ductility, along with resistance to brittle fracture, making it suitable for applications such as boilers, heat exchangers, and other pressure-containing components. The steel is normally supplied in the normalized condition, which refines the grain structure and enhances its mechanical properties.
Chemical Composition
| C | Si | Mn | P | S | Cr | Mo |
| 0.15 max | 0.55 max | 0.25-0.66 max | 0.035 max | 0.035 max | 3.90-6.10 max | 0.40-0.70 max |
Mechanical Properties
| Thickness mm | Yield Min Mpa | Tensile Mpa | Elongation Min % |
| t≦50 | 205 | 415-585 | 18 |
| 50 | - | - | - |
Tensile Requirements for ASME SA387 Grade 5 Alloy Steel Plates Class 1 Plates
| Designation: | Requirement: | Grade 5 |
|
SA387 Grade 5 |
Tensile strength, ksi [MPA] | 75 to 100 [515 to 690] |
| Yield strength, min, ksi [MPa]/(0.2% offset) | 45 [310] | |
| Elongation in 8 in. [200mm], min % | ... | |
| Elongation in 2 in. [50mm], min, % | 18 | |
| Reduction of area, min % | 45 (measured on round specimen) 40 (measured on flat specimen) |
Fabrication Process
1. Standard Heat Treatment Process
According to the ASME SA 387/SA 387M specification, Grade 5 plates must be thermally treated using one of the following methods:
Annealing: Heating above the transformation temperature and cooling slowly in a furnace.
Normalizing and Tempering:
Normalizing: Heating to 900–950°C (1650–1750°F) and cooling in still air.
Tempering: Must be performed at a minimum temperature of 705°C (1300°F).
Accelerated Cooling: If permitted by the purchaser, plates may be liquid quenched or air-blast cooled from the austenitizing temperature, followed by tempering at 705°C (1300°F) minimum.
2. Mechanical Requirements (Class 1)
For Grade 5 Class 1, the following tensile requirements must be met:
Tensile Strength: 60 to 85 ksi [415 to 585 MPa].
Yield Strength (min): 30 ksi [205 MPa] (some sources list 45 ksi / 310 MPa depending on specific test conditions/updates).
Elongation in 2" (min): 18%.
3. Chemical Composition (Grade 5)
Key elements that provide heat and corrosion resistance include:
Chromium (Cr): 4.00% – 6.00% (provides oxidation and corrosion resistance).
Molybdenum (Mo): 0.45% – 0.65% (enhances high-temperature tensile strength and creep resistance).
Carbon (C): 0.15% maximum (maintains good weldability).
4. Technical Characteristics
Weldability: Excellent due to controlled carbon levels.
Temperature Range: Typically used in applications ranging from 316°C to 593°C.
Resistance: Highly resistant to hydrogen embrittlement and thermal cycling failure.
Common Applications: Heat exchangers, reactor vessels, and steam drums in the oil, gas, and petrochemical industries.
Why Choose Us :
You can get the perfect material according to your requirement at the least possible price.
We also offer Reworks, FOB, CFR, CIF, and door to door delivery prices. We suggest you to do deal for shipping which will be quite economical.
The materials we provide are completely verifiable, right from raw material test certificate to the final dimensional statement.(Reports will show on requirement)
We guarantee to give a response within 24hours(usually in the same hour)
You can get stock alternatives, mill deliveries with minimizing manufacturing time.
We are fully dedicated to our customers. If it will not possible to meet your requirements after examining all options, we will not mislead you by making false promises which will create good customer relations.
Contact us at beam@gneesteelgroup.com for pricing, technical support, or customized solutions. We are always ready to support your project.
What is SA 387 Grade 5 Class 1?
SA 387 Grade 5 Class 1 is a specification for carbon‑manganese steel plates used in welded pressure vessels where good notch toughness is required. It is part of the ASME Boiler and Pressure Vessel Code.
Under which part of the ASME Code is SA 387 Grade 5 Class 1 listed?
It is listed in Section II, Part A of the ASME Boiler and Pressure Vessel Code, which covers ferrous materials for boilers and pressure vessels.
What is the primary intended use of SA 387 Grade 5 Class 1?
It is intended for use in welded pressure vessels and pressure-containing components that operate at moderate to elevated temperatures.
What type of steel is SA 387 Grade 5 Class 1?
It is a carbon‑manganese steel, which provides a good balance of strength and ductility.
What key mechanical property does SA 387 Grade 5 Class 1 emphasize?
It emphasizes improved notch toughness, which helps prevent brittle fracture, especially in welded structures.
What are the typical mechanical properties of SA 387 Grade 5 Class 1?
It has moderate strength, good ductility, and acceptable toughness at both room and moderately low temperatures, making it suitable for pressure vessel service.
In what condition is SA 387 Grade 5 Class 1 usually supplied?
It is typically supplied in the normalized condition, which refines the grain structure and improves toughness and strength.
Why is normalization used for SA 387 Grade 5 Class 1?
Normalization is used to refine the grain size, homogenize the microstructure, and enhance the material's toughness and ductility.
Can SA 387 Grade 5 Class 1 be supplied in other heat‑treated conditions?
While normalization is the standard condition, some supplementary requirements may allow for other heat treatments, depending on the purchaser's specification.
What welding processes are commonly used with SA 387 Grade 5 Class 1?
Common welding processes include shielded metal arc welding, gas metal arc welding, flux-cored arc welding, and submerged arc welding, provided appropriate procedures are followed.
Does SA 387 Grade 5 Class 1 require preheating before welding?
Preheating is often recommended, especially for thicker plates or in cold environments, to reduce the risk of hydrogen-induced cracking and ensure sound welds.