ASTM A203 Low Alloy Steel Flange, Grade D

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 A203 Low Alloy Steel Flange, Grade D Product Information -:- For detailed product information, please contact sales. -: ASTM A203 Low Alloy Steel Flange, Grade D Synonyms -:- For detailed product information, please contact sales. -:

ASTM A203 Low Alloy Steel, Grade D Product Information -:- For detailed product information, please contact sales. -: ### **Product Introduction: ASTM A203 Grade D Steel** **ASTM A203 Grade D** is a nickel-alloy steel plate designed for pressure vessel applications requiring excellent low-temperature toughness. With a nominal **3.50% nickel** content, this grade offers superior impact resistance at cryogenic temperatures, making it suitable for severe low-temperature service conditions where enhanced fracture toughness is critical. --- #### **1. International Standards & Grades** **Primary Standard:** **ASTM A203/A203M** - "Standard Specification for Pressure Vessel Plates, Alloy Steel, Nickel" **Grade Classification:** - **Grade D** - 3.50% nickel steel for severe low-temperature service - Other grades: A, B, E, F with varying nickel content **International Equivalents:** - **EN 10028-4**: 12Ni19 - **JIS G3127**: SLA 235B - **GB/T 3531**: 09MnNiDR - **ISO 9328-4**: 12Ni19 --- #### **2. Chemical Composition** The chemical composition requirements for ASTM A203 Grade D: | Element | Composition (Maximum %) | |---|---| | Carbon (C) | 0.17 | | Manganese (Mn) | 0.70 | | Phosphorus (P) | 0.035 | | Sulfur (S) | 0.040 | | Silicon (Si) | 0.30 | | Nickel (Ni) | 3.25-3.75 | **Key Composition Features:** - **Enhanced Nickel Content**: 3.25-3.75% for superior low-temperature toughness - **Low Carbon**: Ensures excellent weldability and fracture resistance - **Controlled Manganese**: Maintains optimal strength-toughness balance - **Restricted Silicon**: Maximizes impact properties --- #### **3. Physical & Mechanical Properties** **Mechanical Properties (for thicknesses ≤ 50 mm):** | Property | Value | |---|---| | **Tensile Strength** | 515-655 MPa (75-95 ksi) | | **Yield Strength (min.)** | 310 MPa (45 ksi) | | **Elongation in 2" (min.)** | 21% | | **Elongation in 8" (min.)** | 24% | **Low-Temperature Toughness Properties:** - **Charpy V-Notch Test Temperature**: -150°F (-101°C) - **Minimum Impact Energy**: 20 ft-lbf (27 J) - **Exceptional Toughness**: Maintains properties at extreme cryogenic temperatures **Physical Properties:** - **Density**: 7.87 g/cm³ (0.284 lb/in³) - **Modulus of Elasticity**: 201 GPa (29,150 ksi) - **Thermal Conductivity**: 48.5 W/m·K - **Coefficient of Thermal Expansion**: 11.4 × 10⁻⁶/°C - **Specific Heat Capacity**: 475 J/kg·K --- #### **4. Product Applications** **Severe Cryogenic Service:** - Liquid ethylene storage tanks - LNG processing equipment - Cryogenic research vessels - Ultra-low temperature storage systems **Chemical Processing:** - Ethylene cracker components - Low-temperature reactor vessels - Cryogenic distillation columns - Specialized chemical process equipment **Energy and Power:** - LNG liquefaction plant equipment - Cryogenic power generation systems - Advanced energy storage vessels - Specialized heat exchangers **Industrial Applications:** - Industrial gas liquefaction equipment - Cryogenic testing facilities - Specialized research equipment - Advanced cooling systems --- #### **5. Fabrication Characteristics** **Welding Performance:** - **Good Weldability**: Requires nickel-matched filler metals - **Preheat Requirements**: 200-250°F (95-120°C) recommended - **Post-Weld Heat Treatment**: Stress relieving at 1100-1150°F (595-620°C) - **Recommended Processes**: GTAW, GMAW, SMAW (low-hydrogen) - **Filler Metals**: ENiCrFe-2, ENiCrFe-3 or equivalent **Forming & Machining:** - **Excellent Formability**: Suitable for complex forming operations - **Machinability**: Good (approximately 65% of B1112 steel) - **Cutting Methods**: Waterjet, laser, and plasma cutting preferred - **Bend Performance**: Superior at low temperatures **Heat Treatment:** - Supplied in normalized and tempered condition - Normalizing temperature: 1550-1650°F (845-900°C) - Tempering temperature: 1100-1200°F (595-650°C) - Microstructural stability ensured **Quality Assurance:** - **Mandatory Impact Testing**: Charpy V-Notch at -150°F (-101°C) - **Chemical Analysis**: Complete heat certification - **Mechanical Testing**: Comprehensive property verification - **Non-Destructive Testing**: UT, RT, PT as specified --- ### **Technical Summary** ASTM A203 Grade D represents a premium nickel-alloy steel engineered for the most demanding cryogenic applications. The 3.50% nickel content provides exceptional toughness at temperatures as low as -150°F (-101°C), making this grade suitable for handling liquefied gases and operating in extreme low-temperature environments. The enhanced nickel content significantly improves the material's fracture toughness and lowers the ductile-to-brittle transition temperature, providing an additional safety margin for critical cryogenic applications. The 45 ksi minimum yield strength offers excellent structural efficiency while maintaining the required toughness properties. This grade demonstrates superior performance in fabricated cryogenic equipment, with welding characteristics that allow for the construction of complex pressure vessels and storage systems. The material's consistent response to thermal processing and reliable mechanical properties make it a preferred choice for engineers designing equipment for the LNG industry, ethylene production, and advanced cryogenic applications. ASTM A203 Grade D has established itself as a reliable solution for severe cryogenic service, offering performance characteristics that bridge the gap between lower nickel grades and more expensive high-nickel alloys. Its proven service history in critical low-temperature applications ensures continued preference among engineers and fabricators working with extreme cryogenic conditions. -:- For detailed product information, please contact sales. -: ASTM A203 Low Alloy Steel, Grade D Specification Dimensions Size： Diameter 20-1000 mm Length <4333 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 A203 Low Alloy Steel, Grade D Properties -:- For detailed product information, please contact sales. -:

Applications of ASTM A203 Low Alloy Steel Flange, Grade D -:- For detailed product information, please contact sales. -: Chemical Identifiers ASTM A203 Low Alloy Steel Flange, Grade D -:- For detailed product information, please contact sales. -:

Packing of ASTM A203 Low Alloy Steel Flange, Grade D -:- 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 804 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