ASTM A738 Carbon Steel Flange, Grade A

1,We Manufacturing processes are primarily classified into four types: 1:Forging, 2:Casting, 3:Cutting, 4:Rolling. 2,We can manufacture in accordance with these standards. Standards: GB Series (Chinese Standards), JB Series (Machinery Standards), HG Series (Chemical Industry Standards), ASME B16.5 (American Standards), BS4504 (British Standards), DIN (German Standards), and JIS (Japanese Standards). Internationally, there are two primary systems of pipe flange standards: the European system, represented by the German DIN standards (including those of the former Soviet Union), and the American system, represented by the US ANSI pipe flange standards. Other common standards include: the Chinese Ministry of Machinery Industry standards (JB series), the Ministry of Chemical Industry standards (HG series), the Chinese National Standard *GB/T 9112–9124-2010 Steel Pipe Flanges*, as well as US standards (ASME B16.5), British standards (BS4504), German standards (DIN), Japanese standards (JIS), and marine standards (CBM), among others. The nominal pressure ratings for the PN series are designated by "PN" and comprise the following nine levels: PN2.5, PN6, PN10, PN16, PN25, PN40, PN63, PN100, and PN160. The nominal pressure ratings for the Class series are designated by "Class" and comprise the following six levels: Class150, Class300, Class600, Class900, Class1500, and Class2500. Flange Classification 1. **According to Chemical Industry Standards:** Flanges are classified as follows: Plate Flat Welding Flange (PL), Necked Flat Welding Flange (SO), Necked Butt Welding Flange (WN), Integral Flange (IF), Socket Welding Flange (SW), Threaded Flange (Th), Butt Welding Ring Loose Flange (PJ/SE), Blind Flange (BL), Flat Welding Ring Loose Flange (PJ/PJ), and Lined Blind Flange (BL(s)). 2. **According to Petrochemical (SH) Industry Standards:** Flanges are classified as follows: Threaded Flange (PL), Butt Welding Flange (WN), Flat Welding Flange (SO), Socket Welding Flange (SW), Loose Flange (LJ), and Blind Flange (no specific designation). 3. **According to Machinery (JB) Industry Standards:** Flanges are classified as follows: Integral Flange, Butt Welding Flange, Plate Flat Welding Flange, Butt Welding Ring Plate Loose Flange, Flat Welding Ring Plate Loose Flange, Lap Joint Ring Plate Loose Flange, and Blind Flange. 4. **According to Connection Method/Type:** Flanges are classified as follows: Plate Flat Welding Flange, Necked Flat Welding Flange, Necked Butt Welding Flange, Socket Welding Flange, Threaded Flange, Blind Flange, Necked Butt Welding Ring Loose Flange, Flat Welding Ring Loose Flange, Ring-Type Joint (RTJ) Flange and Blind Flange, Large-Diameter Plate Flange, Large-Diameter High-Neck Flange, Figure-8 Blind Plate, Butt Welding Ring Loose Flange, etc. 5. **According to the Component Being Connected:** Flanges can be classified into Vessel Flanges and Pipe Flanges. 6. **According to Structural Type:** Flanges include Integral Flanges, Threaded Flanges, Flat Welding Flanges, Butt Welding Flanges, Lap Joint (Loose/Swivel) Flanges, and Blind Flanges. A flange—also referred to as a flange plate or rim—is a component used to connect shafts to one another, or, more commonly, to join the ends of pipes. Flanges are also utilized at the inlet and outlet ports of equipment to facilitate connections between two devices—for instance, the flange on a speed reducer. A "flange connection" or "flanged joint" refers to a detachable joint assembly comprising three interconnected elements—a flange, a gasket, and bolts—that together form a sealed structural unit. In the context of piping systems, a "pipe flange" specifically denotes a flange used for plumbing within the installation; when applied to equipment, it refers to the inlet or outlet flange of that specific device. Flanges feature a series of holes through which bolts are inserted to securely fasten the two flanges together, while a gasket placed between the flanges ensures a leak-proof seal. Flanges are broadly categorized into three types: threaded (screw-in) flanges, welded flanges, and clamp-type flanges. Flanges are invariably used in pairs; threaded flanges are suitable for low-pressure piping applications, whereas welded flanges are required for systems operating at pressures exceeding 4 kilograms per square centimeter. A sealing gasket is inserted between the two flange plates, which are then firmly secured using bolts. The thickness of a flange—as well as the specifications of the bolts used to fasten it—vary depending on the specific pressure rating required for the application. When connecting equipment such as water pumps or valves to piping systems, the corresponding connection points on these devices are often manufactured in the shape of a matching flange; this method of attachment is also referred to as a "flange connection." Generally, any connecting component that utilizes bolts to join and seal the perimeters of two flat surfaces—such as the joints in ventilation ducts—is termed a "flange"; such components may collectively be classified as "flange-type parts." However, since such a connection often constitutes merely a *portion* of a larger device—for instance, the interface between a flange and a water pump—it would be inappropriate to classify the entire water pump itself as a "flange-type part." Conversely, smaller components—such as valves—that feature such flanged interfaces may indeed be appropriately categorized as "flange-type parts." -:- For detailed product information, please contact sales. -: ASTM A738 Carbon Steel Flange, Grade A Product Information -:- For detailed product information, please contact sales. -: ASTM A738 Carbon Steel Flange, Grade A Synonyms -:- For detailed product information, please contact sales. -:

ASTM A738 Carbon Steel, Grade A Product Information -:- For detailed product information, please contact sales. -: # **Product Introduction: ASTM A738 Grade A Carbon-Manganese-Silicon Steel for Pressure Vessels** **ASTM A738 Grade A** is a **heat-treated carbon-manganese-silicon steel plate** specifically designed for **welded pressure vessels requiring a precise balance of strength and notch toughness at low temperatures**. This grade offers a **minimum yield strength of 50 ksi (345 MPa)** and is distinguished by its **mandatory heat treatment requirements and stringent impact toughness testing**. Unlike conventional carbon steels, A738 Grade A is supplied exclusively in the **normalized, normalized and tempered, or quenched and tempered condition**, ensuring refined grain structure and uniform mechanical properties essential for reliable performance in demanding service environments. --- ## **International Standard & Key Specifications** * **Primary Standard:** **ASTM A738/A738M** - Standard Specification for Pressure Vessel Plates, Heat-Treated, Carbon-Manganese-Silicon Steel, for Moderate and Lower Temperature Service. * **Key Distinction:** This specification **requires heat treatment** for all plates, distinguishing it from many other carbon steel pressure vessel specifications that may offer as-rolled products. * **ASME Code Equivalent:** **SA-738/SA-738M** in ASME Boiler and Pressure Vessel Code, Section II, Part A. Mandatory for ASME-stamped pressure equipment. * **Governing Standard:** **ASTM A20/A20M** - Standard Specification for General Requirements for Steel Plates for Pressure Vessels. * **Impact Test Requirement:** A defining feature - all plates must be **Charpy V-notch impact tested**, with specific minimum energy values required at designated temperatures. --- ## **Chemical Composition (Weight %, max unless range is specified)** The composition is controlled to achieve good hardenability for heat treatment while maintaining excellent weldability and toughness. | Element | Composition (%) | Role in Performance | | :--- | :--- | :--- | | **Carbon (C)** | 0.24 max | Provides strength; controlled to balance weldability with hardenability for heat treatment. | | **Manganese (Mn)** | 0.85 - 1.50 | Enhances strength and hardenability; improves response to heat treatment. | | **Phosphorus (P)** | 0.035 max | Impurity, kept low for good notch toughness. | | **Sulfur (S)** | 0.040 max | Impurity, controlled for optimal weldability and ductility. | | **Silicon (Si)** | 0.15 - 0.40 | Deoxidizer and solid solution strengthener. | | **Nickel (Ni)** | **0.40 max (optional)** | May be added by agreement to enhance low-temperature toughness. | | **Copper (Cu)** | 0.35 max | Residual element, may be present. | | **Vanadium (V)** | 0.05 max | May be present as a microalloying addition for grain refinement. | | **Carbon Equivalent (CE)** | Typically ≤ 0.45 | Calculated per specification to ensure good weldability. | **Note:** The optional addition of nickel (up to 0.40%) can significantly improve impact toughness, particularly for lower temperature applications. --- ## **Typical Physical & Mechanical Properties** Properties are guaranteed after the specified heat treatment (normalized, normalized and tempered, or quenched and tempered). | Property | Value / Description | Condition | | :--- | :--- | :--- | | **Tensile Strength** | 485 - 620 MPa (70,000 - 90,000 psi) | N, N&T, or Q&T | | **Yield Strength (min)** | **345 MPa (50,000 psi)** | N, N&T, or Q&T | | **Elongation in 2-in (50 mm) (min)** | 21% | N, N&T, or Q&T | | **Modulus of Elasticity** | ~200 GPa (29 x 10⁶ psi) | -- | | **Density** | ~7.85 g/cm³ (0.284 lb/in³) | -- | | **Charpy V-Notch Impact Toughness** | **Test Temperature:** **-50°F (-45°C)**. **Minimum Avg. for 3 Specimens:** **20 ft·lbf (27 J)**. **Minimum Single Value:** 15 ft·lbf (20 J). | **Mandatory requirement** | | **Brinell Hardness (typical)** | 170 - 220 HBW | Normalized condition | --- ## **Product Applications** ASTM A738 Grade A is engineered for pressure vessel applications where reliable low-temperature toughness is essential, particularly in environments where thermal cycles or sudden temperature changes may occur. **Primary Industries and Equipment:** 1. **Petrochemical & Gas Processing:** * **Low-Temperature Separators** and **Scrubbers** in natural gas processing plants. * **Ammonia Storage Vessels** and related equipment. * **LPG (Liquefied Petroleum Gas) Storage Tanks** operating at moderate to low temperatures. 2. **Power Generation:** * **Feedwater Heaters** and **Deaerators**. * **Condenser Shells** and associated low-temperature pressure vessels. * **Hydrogen Coolers** in turbine-generator systems. 3. **Industrial Refrigeration & Cryogenics:** * **Vessels for Industrial Refrigeration Systems**. * **Storage Tanks** for carbon dioxide and certain refrigerants. * **Process Equipment** in food processing and chemical plants requiring low-temperature operation. 4. **General Pressure Vessel Fabrication:** * **Custom Pressure Vessels** designed for service at or below ambient temperature. * **Heat Exchangers** operating with cold process streams. --- ## **Advantages and Critical Fabrication Considerations** * **Advantages:** * **Guaranteed Low-Temperature Toughness:** Mandatory impact testing at -50°F ensures reliable performance in low-temperature service. * **Consistent Properties:** Heat treatment provides uniform microstructure and mechanical properties throughout the plate thickness. * **Good Weldability:** Moderate carbon content and controlled composition result in good weldability with proper procedures. * **Versatile Heat Treatment Options:** Available in normalized, normalized and tempered, or quenched and tempered conditions to optimize properties for specific applications. * **Critical Fabrication & Welding Considerations:** * **Heat Treatment Stability:** Post-fabrication heat treatment must consider the original heat treatment of the plate to avoid degradation of properties. * **Welding Requirements:** **Low-hydrogen welding practices are essential**. Preheat is typically required, especially for thicker sections and when welding in the quenched and tempered condition. * **Impact Test Verification:** Welding Procedure Specifications (WPS) may require impact testing of weld metal and heat-affected zone to ensure toughness compatibility. * **Post-Weld Heat Treatment (PWHT):** Often required for pressure vessel fabrication; parameters must be carefully controlled. * **Thermal Cutting:** For quenched and tempered material, thermal cutting may require preheat to prevent localized hardening and cracking. * **Thickness Limitations:** Mechanical properties, particularly toughness, may vary with plate thickness; design should consider the specific thickness being used. **In summary, ASTM A738 Grade A is a heat-treated carbon steel plate that provides guaranteed strength and reliable notch toughness at temperatures down to -50°F. Its mandatory heat treatment and impact testing requirements make it a preferred choice for pressure vessels operating in low-temperature environments where fracture resistance is critical. The material offers engineers a cost-effective solution for applications requiring better low-temperature performance than conventional as-rolled carbon steels, while maintaining good fabricability for pressure vessel construction.** -:- For detailed product information, please contact sales. -: ASTM A738 Carbon Steel, Grade A Specification Dimensions Size： Diameter 20-1000 mm Length <4534 mm Size:We can customized as required Standard： Per your request or drawing We can customized as required Properties（Theoretical） Chemical Composition -:- For detailed product information, please contact sales. -: ASTM A738 Carbon Steel, Grade A Properties -:- For detailed product information, please contact sales. -:

Applications of ASTM A738 Carbon Steel Flange, Grade A -:- For detailed product information, please contact sales. -: Chemical Identifiers ASTM A738 Carbon Steel Flange, Grade A -:- For detailed product information, please contact sales. -:

Packing of ASTM A738 Carbon Steel Flange, Grade A -:- For detailed product information, please contact sales. -: Standard Packing: -:- For detailed product information, please contact sales. -: Typical bulk packaging includes palletized plastic 5 gallon/25 kg. pails, fiber and Steel Flange drums to 1 ton super sacks in full container (FCL) or truck load (T/L) quantities. Research and sample quantities and hygroscopic, oxidizing or other air sensitive materials may be packaged under argon or vacuum. Solutions are packaged in polypropylene, plastic or glass jars up to palletized 1005 gallon liquid totes Special package is available on request. E FORUs’ is carefully handled to minimize damage during storage and transportation and to preserve the quality of our products in their original condition