ASTM A515 Grade 65 is a carbon steel plate material specifically developed for use in pressure vessels and boiler components that operate at moderate to elevated temperatures. It is part of the ASTM A515 specification, which covers carbon steel plates intended for service in high-temperature pressure applications. Grade 65 is characterized by its relatively high tensile and yield strength, good weldability, and reliable performance under conditions involving heat and pressure. This material is widely used in industries such as power generation, petrochemical processing, and general pressure vessel fabrication, where it provides a cost-effective solution without compromising structural integrity or durability.
| Physical Properties | Metric | English | Comments |
|---|---|---|---|
| Density | 7.80 g/cc | 0.282 lb/in³ | Typical of ASTM Steel |
| Mechanical Properties | Metric | English | Comments |
| Tensile Strength, Ultimate | 450 - 585 MPa | 65300 - 84800 psi | |
| Tensile Strength, Yield | 240 MPa | 34800 psi | |
| Elongation at Break | 19 % | 19 % | in 200mm |
| 23 % | 23 % | in 50mm | |
| Modulus of Elasticity | 200 GPa | 29000 ksi | Typical Carbon Steel |
| Bulk Modulus | 160 GPa | 23200 ksi | Typical for Steel |
| Poissons Ratio | 0.29 | 0.29 | Typical Carbon Steel |
| Shear Modulus | 80.0 GPa | 11600 ksi | Typical for Steel |
| Electrical Properties | Metric | English | Comments |
| Electrical Resistivity | 0.0000170 ohm-cm | 0.0000170 ohm-cm | Typical Carbon Steel |
| Thermal Properties | Metric | English | Comments |
| CTE, linear | 12.0 µm/m-°C | 6.67 µin/in-°F | Typical Carbon Steel |
| Specific Heat Capacity | 0.470 J/g-°C | 0.112 BTU/lb-°F | Typical Carbon Steel |
| Thermal Conductivity | 52.0 W/m-K | 361 BTU-in/hr-ft²-°F | Typical Carbon Steel |
| Component Elements Properties | Metric | English | Comments |
| Carbon, C | 0.33 % | 0.33 % | may vary with plate thickness |
| Iron, Fe | 98.42 % | 98.42 % | as balance |
| Manganese, Mn | 0.90 % | 0.90 % | |
| Phosphorus, P | 0.035 % | 0.035 % | |
| Silicon, Si | 0.15 - 0.40 % | 0.15 - 0.40 % | |
| Sulfur, S | 0.040 % | 0.040 % | |
Processing Flow
Steelmaking: Refine molten iron to meet the required carbon and manganese content, while strictly controlling and minimizing impurities (such as sulfur and phosphorus) to ensure the material's basic performance.
Slab Casting: Cast the refined molten steel into slabs through continuous casting or ingot casting processes, which serve as the raw material for subsequent rolling.
Hot Rolling: Heat the slabs to a controlled high temperature and perform rolling operations to form steel plates of the desired thickness. This process helps optimize the material's grain structure and enhance its mechanical properties.
Heat Treatment (Normalizing): Conduct normalizing heat treatment on the rolled steel plates (especially thick plates). Heat the material to an appropriate temperature, hold it for a certain period, and then cool it in air to improve toughness, structural uniformity and dimensional stability.
Quality Inspection: Perform strict non-destructive testing (such as ultrasonic testing) and mechanical property testing on the steel plates to ensure they fully comply with ASTM A515 Grade 65 standards, eliminating defects like internal cracks or inclusions.
Cutting & Forming: Cut the qualified steel plates into specific sizes according to actual application needs, and carry out forming processes (such as bending, pressing) to make semi-finished products matching the shape of components.
Welding: Weld the semi-finished products into final components (e.g., boiler drums, pressure vessel shells) using common welding processes (SMAW, GMAW, etc.), leveraging the material's excellent weldability to ensure firm and leak-proof joints.
Final Finishing & Inspection: Conduct surface finishing (such as derusting, cleaning) on the welded components and perform a final overall inspection to confirm that the finished products meet the technical requirements of end-use scenarios.
applications
Boiler Manufacturing: Used for high‑temperature boilers in power plants and industrial heating systems, particularly in steam drums, where it withstands long‑term high‑temperature steam and pressure without deformation or leakage.
Petrochemical Industry: Applied in medium‑pressure hydrogenation reactors and catalytic cracking regenerators operating at 300–380°C and 4–8MPa. Also used for shells of tube‑and‑shell heat exchangers, welding reliably with 304 stainless steel tubes at 200–350°C, and for LPG and propylene storage tanks to avoid low‑temperature cracking.
Power Generation Industry: Utilized in thermal and nuclear power auxiliary equipment for steam pipelines and heat recovery systems, enduring continuous high‑temperature, high‑pressure steam scouring to ensure safe and efficient operation.
General Pressure Vessel Fabrication: Used for separators, spherical tanks, gas storage tanks, and other pressure vessels in chemical and metallurgical industries, providing the mechanical strength needed for long‑term pressure service.
High‑Pressure Pipeline Manufacturing: Rolled and welded into spiral or straight‑seam pipes for medium‑pressure steam (250–350°C, 3–5MPa), offering good strength and sealing for long‑distance transport with low leakage risk.
Request a professional quotation for A515 Grade 65 from GNEE Steel.
What heat treatment is applied to A515 Grade 65?
A515 Grade 65 plates are usually supplied in the as-rolled or normalized condition. Normalizing involves heating the steel to a temperature above the critical range and then air-cooling, which refines the grain structure and improves toughness and uniformity. For thicker plates or specific applications, quenching and tempering may be used to achieve higher strength and better impact properties, although this is less common for standard A515 grades.
What is the impact toughness requirement for A515 Grade 65?
A515 Grade 65 must meet certain impact toughness requirements, typically measured by Charpy V-notch tests. While the exact values depend on plate thickness and heat treatment, the material generally exhibits adequate toughness for pressure vessel service at ambient and moderately low temperatures. For applications requiring improved low-temperature toughness, producers may offer supplementary impact testing or modified chemistry.
Can A515 Grade 65 be used in low-temperature environments?
A515 Grade 65 is primarily designed for elevated-temperature service and may not provide sufficient toughness at very low temperatures. It can be used at moderately low temperatures, but for applications below approximately 0°F (-18°C), grades such as A516, which are specifically formulated for low-temperature toughness, are more appropriate. Using A515 in cold service without proper evaluation may risk brittle fracture.
What is the density of A515 Grade 65 steel?
The density of A515 Grade 65 is approximately 7.85 grams per cubic centimeter, similar to other carbon steels. This density is consistent across most carbon and low-alloy steels used in pressure vessel applications. Knowing the density is important for weight calculations in vessel design, transportation, and structural analysis, helping engineers optimize material usage and structural integrity.
What is the modulus of elasticity for A515 Grade 65?
A515 Grade 65 has a modulus of elasticity of about 29 million psi (200 GPa) at room temperature, typical of carbon steels. This value is used in structural and pressure vessel design to calculate deflection, stress distribution, and thermal expansion effects. The modulus remains relatively constant over a range of temperatures, although it decreases slightly at higher temperatures, affecting design considerations for high-temperature service.
What is the coefficient of thermal expansion for A515 Grade 65?
A515 Grade 65 has a coefficient of thermal expansion of approximately 6.5 × 10^-6 per °F (11.7 × 10^-6 per °C) between 70°F and 600°F. This property is crucial for designing pressure vessels that experience significant temperature changes, as it helps predict dimensional changes and thermal stresses. Engineers use this data to prevent buckling, fatigue, and failure due to thermal cycling.
What is the thermal conductivity of A515 Grade 65?
The thermal conductivity of A515 Grade 65 is around 26 to 30 W/m·K at room temperature, decreasing slightly at higher temperatures. Good thermal conductivity is important for boiler and heat exchanger applications, as it allows efficient heat transfer between fluids and the vessel walls. This property, combined with its strength, makes A515 Grade 65 suitable for high-temperature heat transfer equipment.
What is the melting point range of A515 Grade 65?
A515 Grade 65 has a melting point range similar to other carbon steels, typically between 2600°F and 2800°F (1425°C and 1540°C). The exact range depends on the chemical composition, particularly the carbon and alloy content. Understanding the melting point is important for welding and heat treatment processes, as it helps determine appropriate temperatures for heating, forging, and avoiding overheating or burning during fabrication.
What are the common forms of A515 Grade 65 supplied?
A515 Grade 65 is most commonly supplied as hot-rolled steel plates in various thicknesses and widths. Plates may be cut to size, beveled for welding, or processed further into vessel components. Some producers also offer normalized or quenched and tempered plates, depending on customer specifications. The material is rarely supplied as bars or shapes, as its primary application is pressure vessel plates.
What are the typical applications of A515 Grade 65 in the oil and gas industry?
In the oil and gas industry, A515 Grade 65 is used for pressure vessels, separators, and heat exchangers in refineries and processing plants. It is suitable for moderate-temperature services such as crude oil distillation units and process heaters. Its strength and weldability make it a reliable choice for fabricating large-diameter vessels and thick-walled components subjected to internal pressure and thermal loads.