AISI 8720 Steel Flange

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. -: AISI 8720 Steel Flange Product Information -:- For detailed product information, please contact sales. -: AISI 8720 Steel Flange Synonyms -:- For detailed product information, please contact sales. -:

AISI 8720 Steel Product Information -:- For detailed product information, please contact sales. -: ### **Product Introduction: AISI 8720 Steel** #### **1. Overview** AISI 8720 is a **boron-modified nickel-chromium-molybdenum (Ni-Cr-Mo-B) alloy steel** within the AISI 8700 series, specifically designed as a **high-performance case-hardening (carburizing) grade**. The intentional addition of **boron (B)**, typically in minute quantities (0.0005-0.003%), significantly enhances the hardenability of the steel without substantially increasing the alloying element content or cost. This results in a material that offers **excellent core hardenability and strength** at a favorable economic profile. Following carburizing heat treatment, AISI 8720 develops a deep, hard wear-resistant case over a tough, strong core, making it a **cost-effective alternative** to higher-alloy grades like AISI 8620/8622 for many medium-to-heavy duty applications. #### **2. International Standards & Designations** AISI 8720 is recognized under several international standards, with notable equivalents that account for its boron content. | Region/System | Standard Designation | Title / Purpose | | :--- | :--- | :--- | | **USA (AISI/SAE)** | **AISI 8720, SAE J404** | Standard Chemical Composition | | **USA (ASTM)** | **ASTM A322** | Standard Specification for Steel Bars, Alloy, Standard Grades | | **USA (ASTM)** | **ASTM A534** | Carburizing Steels for Anti-Friction Bearings | | **UNS Number** | **G87200** | Unified Numbering System | | **Europe (EN)** | **20NiCrMoS2-2 (with B)** | Equivalent Boron-Treated Grade (Note: Direct EN equivalent often references boron addition) | | **Germany (DIN/W-Nr.)** | **20NiCrMo2-2 +B** | Boron-Treated Equivalent Designation | | **Japan (JIS)** | **SNC815H / SNCM220H** | Similar Hardenability Grades | | **Boron Steel Ref.** | **ASTM A304 (Grade 86B20)** | Often cross-referenced for boron hardenability steels | #### **3. Chemical Composition** The key distinction of AISI 8720 lies in its boron content, which dramatically increases hardenability. Its base composition is similar to AISI 8620. | Element | Content (% by Weight) | Metallurgical Role | | :--- | :--- | :--- | | **Carbon (C)** | 0.18 - 0.23 | Provides base core strength; sufficient for effective case carburizing. | | **Manganese (Mn)** | 0.70 - 0.90 | Enhances hardenability and strength. | | **Phosphorus (P)** | ≤ 0.035 | Impurity control. | | **Sulfur (S)** | ≤ 0.040 | Impurity control; sometimes slightly increased for machinability. | | **Silicon (Si)** | 0.15 - 0.35 | Deoxidizer and strengthener. | | **Nickel (Ni)** | 0.40 - 0.70 | Enhances core toughness and hardenability. | | **Chromium (Cr)** | 0.40 - 0.60 | Increases hardenability and wear resistance of the case. | | **Molybdenum (Mo)** | 0.20 - 0.30 | Slightly higher range than 8620; increases hardenability and temper resistance. | | **Boron (B)** | **0.0005 - 0.003** | **Key Differentiator:** A potent hardenability intensifier. It segregates to austenite grain boundaries, delaying the transformation to softer phases (ferrite, pearlite) during quenching, thereby promoting deeper martensite formation. | | **Iron (Fe)** | Balance | Base metal. | #### **4. Mechanical & Physical Properties** *Properties are condition-dependent. The following represents typical ranges.* **As-Supplied (Annealed) Properties:** * **Hardness:** **149 - 197 HB** (Brinell) * **Tensile Strength:** **520 - 690 MPa** (75 - 100 ksi) * **Yield Strength:** **385 - 550 MPa** (56 - 80 ksi) * **Elongation:** **20% - 26%** * **Machinability:** **~60%** of B1112 steel. Good with proper tooling. **Properties After Case Hardening (Carburized & Hardened):** * **Surface Case Hardness:** **58 - 63 HRC** (Rockwell C) * **Effective Case Depth:** Can achieve greater depths for a given section size compared to non-boron grades like 8620, due to higher hardenability. * **Core Hardness:** **32 - 45 HRC** (Capable of higher values in larger sections than 8620). * **Core Tensile Strength:** **950 - 1300 MPa** (138 - 189 ksi) * **Core Yield Strength:** **750 - 1100 MPa** (109 - 160 ksi) * **Impact Toughness:** Good, maintained by nickel content. **Physical Properties (Core):** * **Density:** **7.85 g/cm³** * **Modulus of Elasticity:** **205 GPa** * **Poisson's Ratio:** **0.29** * **Thermal Conductivity:** **~45 W/m·K** at 100°C * **Coefficient of Thermal Expansion:** **12.5 × 10⁻⁶/°C** #### **5. Product Applications** AISI 8720 is widely used in applications requiring good hardenability and core strength at a competitive cost. It is often chosen as a substitute for more expensive alloy grades. * **Automotive Components:** Transmission gears, differential gears, pinions, shafts, and synchronizers in passenger cars and light trucks. * **General Industrial Gearing:** Gears and pinions for agricultural machinery, construction equipment, and material handling systems. * **Bearing Components:** Races and rollers for medium-duty bearings. * **Off-Highway Equipment:** Components for tractors, combines, and other mobile machinery. * **Fluid Power Components:** Gears and shafts in hydraulic pumps and motors. * **Fasteners & Pins:** High-strength bolts, studs, and dowel pins requiring case hardening. #### **6. Key Characteristics & Advantages** * **Cost-Effective Hardenability:** The primary advantage. Boron provides a significant boost in hardenability at a much lower cost than achieving similar depth of hardening through increased nickel, chromium, or molybdenum content. This makes 8720 a **high-value engineering material**. * **Good Core Strength in Larger Sections:** Capable of achieving satisfactory core properties in larger cross-sections than a non-boron grade like 8620, allowing for design flexibility. * **Deep Case Potential:** The enhanced hardenability supports the development of deeper effective case depths if required by the application. * **Good Toughness:** Maintains adequate impact resistance due to its nickel content. * **Good Machinability and Formability:** In the annealed condition, it can be readily machined and formed. * **Weldability:** Fair to good with proper precautions (preheat, low-hydrogen electrodes), though the boron content requires careful procedure to avoid cracking in the heat-affected zone. **Important Processing Notes:** * **Boron Effectiveness:** Boron's hardenability effect is most potent in leaner alloy steels and is maximized with sufficient titanium or aluminum to protect it by forming stable nitrides/oxides. * **Quenching:** Requires adequate quench severity to realize the boron hardenability benefit, typically oil quenching. * **Not for Nitriding:** Boron can adversely affect nitrided case properties; 8720 is not typically recommended for nitriding processes. **Conclusion:** **AISI 8720 is a strategically engineered, cost-optimized case-hardening steel that leverages the powerful hardenability effect of boron.** It delivers a performance profile often comparable to higher-alloy grades (like 8620/8622) at a more favorable material cost, making it a popular choice for **high-volume, cost-sensitive applications** across the automotive and general industrial sectors. Its success lies in providing an excellent balance of **performance, processability, and economics.** For designers and manufacturers seeking a reliable material for components that require a good combination of surface wear resistance and core strength without specifying premium alloy content, AISI 8720 presents a compelling and proven solution. -:- For detailed product information, please contact sales. -: AISI 8720 Steel Specification Dimensions Size： Diameter 20-1000 mm Length <5747 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. -: AISI 8720 Steel Properties -:- For detailed product information, please contact sales. -:

Applications of AISI 8720 Steel Flange -:- For detailed product information, please contact sales. -: Chemical Identifiers AISI 8720 Steel Flange -:- For detailed product information, please contact sales. -:

Packing of AISI 8720 Steel Flange -:- 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 2218 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