AISI 5120 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 5120 Steel Flange, heat treated, machined to 25 mm, pseudocarburized, reheated to 775°C (1430°F), 150°C (300°F) temper Product Information -:- For detailed product information, please contact sales. -: AISI 5120 Steel Flange, heat treated, machined to 25 mm, pseudocarburized, reheated to 775°C (1430°F), 150°C (300°F) temper Synonyms -:- For detailed product information, please contact sales. -:

AISI 5120 Steel, heat treated, machined to 25 mm, pseudocarburized, reheated to 775°C (1430°F), 150°C (300°F) temper Product Information -:- For detailed product information, please contact sales. -: # **AISI 5120 Steel - Special Processing Condition Technical Specification** ## **1. Product Overview & Processing Summary** **AISI 5120 steel processed under the specified conditions** represents a material subjected to a **specialized thermomechanical treatment sequence** designed to simulate core properties after carburizing while enabling precise machining to final dimensions. This specific processing route creates a material with **enhanced core strength and toughness** suitable for components that would normally undergo carburizing but require dimensional stability and machinability after heat treatment. **Processing Sequence Summary:** 1. **Initial Heat Treatment:** Full hardening and tempering 2. **Precision Machining:** Machined to 25mm final dimensions 3. **Pseudo-Carburizing:** Thermal cycle simulating carburizing temperature exposure 4. **Reheating:** 775°C (1430°F) - below Ac1 (intercritical annealing) 5. **Final Tempering:** 150°C (300°F) **Result:** A material with **optimized core properties** (no actual carburized case) suitable for applications where the final component will be assembled with separately produced hardened surfaces or where case hardening is not required but the core properties of a case-hardening steel are desired. --- ## **2. Chemical Composition (SAE J404/J412)** | Element | Composition Range (%) | Role in This Application | |---------|----------------------|--------------------------| | **Carbon (C)** | 0.17 - 0.22 | Provides core strength; higher than 5115 for increased hardenability | | **Manganese (Mn)** | 0.70 - 0.90 | Enhances core hardenability and strength | | **Phosphorus (P)** | ≤ 0.035 | Controlled impurity | | **Sulfur (S)** | ≤ 0.040 | Typically low for better transverse properties | | **Silicon (Si)** | 0.15 - 0.35 | Strengthens ferrite, provides solid solution strengthening | | **Chromium (Cr)** | 0.70 - 0.90 | Enhances core hardenability and tempering resistance | | **Iron (Fe)** | Balance | Base matrix | **Note:** This specific processing sequence utilizes the standard 5120 chemistry but develops unique mechanical properties through controlled thermal processing. --- ## **3. Detailed Processing Parameters & Metallurgical Effects** ### **Step-by-Step Processing:** **1. Initial Heat Treatment:** - **Purpose:** Establish baseline microstructure - **Typical Process:** Austenitize at 870-900°C, oil quench, temper to required hardness for machining - **Result:** Tempered martensite structure **2. Precision Machining to 25mm:** - **Machining Condition:** Material in tempered state (typically 25-35 HRC) - **Tolerance:** Close dimensional control (±0.025mm typical) - **Surface Finish:** 0.8-3.2 μm Ra achievable - **Significance:** Machining after initial hardening minimizes distortion concerns **3. Pseudo-Carburizing Thermal Cycle:** - **Purpose:** Simulate thermal exposure of carburizing without carbon addition - **Temperature:** Typically 925°C (1700°F) - standard carburizing temperature - **Time:** Equivalent to intended carburizing cycle (typically 2-8 hours) - **Atmosphere:** Inert or slightly reducing to prevent decarburization - **Metallurgical Effect:** Grain growth control, stress relief, microstructural homogenization **4. Reheating to 775°C (1430°F):** - **Metallurgical Significance:** Intercritical annealing temperature (between Ac1 and Ac3) - **Phase Transformation:** Partial austenitization (α + γ region) - **Result:** Dual-phase microstructure (ferrite + austenite) that transforms to fine martensite on cooling - **Soak Time:** Typically 30-60 minutes for 25mm section **5. Quenching from 775°C:** - **Method:** Oil quench or forced air, depending on hardenability requirements - **Result:** Fine martensite with some retained ferrite **6. Tempering at 150°C (300°F):** - **Duration:** 1-2 hours minimum - **Purpose:** Stress relief without significant hardness reduction - **Effect on Microstructure:** Tempered martensite with fine carbides --- ## **4. Resultant Physical & Mechanical Properties** ### **Microstructural Characteristics:** - **Primary Phase:** Fine tempered martensite - **Secondary Phase:** Small amount of retained ferrite (5-15%) - **Carbide Distribution:** Fine, uniformly dispersed carbides - **Grain Size:** ASTM 8-10 (very fine) - **Prior Austenite Grain Size:** Refined due to intercritical processing ### **Mechanical Properties (25mm diameter):** | Property | Typical Value Range | Test Standard | |----------|---------------------|---------------| | **Hardness** | 38-45 HRC | ASTM E18 | | **Tensile Strength** | 1200-1400 MPa (174-203 ksi) | ASTM E8/E8M | | **Yield Strength (0.2% offset)** | 1000-1200 MPa (145-174 ksi) | ASTM E8/E8M | | **Elongation (in 4D)** | 10-15% | ASTM E8/E8M | | **Reduction of Area** | 35-50% | ASTM E8/E8M | | **Impact Toughness (Charpy V-notch, 25°C)** | 30-50 J | ASTM E23 | | **Fatigue Strength (Rotating Beam, R=-1)** | 450-550 MPa | ASTM E466 | | **Modulus of Elasticity** | 205 GPa (29,700 ksi) | ASTM E111 | ### **Section Size Sensitivity:** - **25mm Diameter:** Optimal for this processing route - **<25mm:** Higher cooling rates may increase hardness slightly - **>25mm:** Lower cooling rates may decrease hardness; modified processing required ### **Residual Stress State:** - **Surface:** Moderate compressive stresses (150-250 MPa) - **Core:** Near-neutral or slight tension - **Stress Distribution:** More uniform than conventional through-hardening --- ## **5. Material Advantages & Unique Characteristics** ### **Benefits of This Processing Route:** **Dimensional Advantages:** - ✅ **Machining after initial hardening** minimizes final distortion - ✅ **Stable dimensions** after final thermal cycles - ✅ **Precise final machining** to 25mm before final heat treatment **Metallurgical Advantages:** - ✅ **Refined microstructure** from intercritical processing - ✅ **Excellent strength-toughness balance** - ✅ **Good fatigue resistance** without carburized case - ✅ **Minimal distortion** compared to conventional carburizing **Processing Advantages:** - ✅ **Eliminates grinding allowance** (no carburized case to remove) - ✅ **Simplifies manufacturing flow** - ✅ **Reduces total processing time** compared to full carburizing - ✅ **Energy efficient** (lower final heat treatment temperature) ### **Comparison with Conventional Processing:** | Property | This Process | Conventional Carburized 5120 | |----------|--------------|-----------------------------| | **Surface Hardness** | 38-45 HRC | 58-63 HRC (case) | | **Core Hardness** | 38-45 HRC | 25-40 HRC | | **Case Depth** | None | 0.5-2.0 mm | | **Machining Sequence** | After initial HT | Before carburizing | | **Distortion** | Minimal | Significant (requires grinding) | | **Fatigue Strength** | Good | Excellent (with case) | | **Production Cost** | Lower | Higher | --- ## **6. Product Applications** ### **Ideal Applications:** **Power Transmission Components:** - **Gear Cores:** Where teeth are separately hardened and attached - **Shafts:** Requiring high strength with precise dimensions - **Splined Components:** Where dimensional accuracy is critical **Automotive Applications:** - **Steering Components:** Tie rods, linkage arms (where surface hardening not needed) - **Suspension Parts:** Non-wearing structural components - **Engine Components:** Non-contact rotating parts **Industrial Machinery:** - **Precision Arbors and Mandrels** - **Fixture and Tooling Components** - **Machine Tool Elements** requiring dimensional stability **Specialized Applications:** - **Aerospace Components:** Where weight and precision are critical - **Medical Devices:** Surgical instrument components - **Hydraulic Components:** Precision pistons and rods ### **Application Limitations:** - ❌ **Not suitable** for applications requiring wear-resistant surfaces - ❌ **Not recommended** for high-contact stress applications - ❌ **Avoid** in corrosive environments without protection --- ## **7. International Standards & Specifications** ### **Base Material Standards:** | Standard | Designation | Reference | |----------|-------------|-----------| | **SAE/AISI** | **5120** | SAE J404, J412 | | **UNS** | **G51200** | Unified Numbering System | | **ASTM** | - | A322 (Standard for Steel Bars) | ### **International Equivalent Grades:** | Region | Standard | Equivalent | Notes | |--------|----------|-----------|-------| | **Europe** | EN 10084 | **20Cr4** | 1.7027 | | **Germany** | DIN 17210 | **20Cr4** | Similar composition | | **Japan** | JIS G4105 | **SCr420** | Close equivalent | | **China** | GB/T 5216 | **20Cr** | Chinese standard | ### **Processing Standards Reference:** - **Heat Treatment:** AMS 2759 (Pyrometry) - **Microstructure:** ASTM E112 (Grain Size) - **Hardness Testing:** ASTM E18 (Rockwell) - **Tensile Testing:** ASTM E8/E8M --- ## **8. Quality Control & Inspection** ### **Critical Inspection Points:** **1. Dimensional Verification (After Machining):** - Diameter: 25mm ±0.025mm - Straightness: ≤0.05mm per 100mm - Surface Finish: 0.8-3.2 μm Ra **2. Microstructural Requirements:** - **Grain Size:** ASTM 8 minimum - **Microcleanliness:** Inclusion rating per ASTM E45 - **Microstructure:** Fine tempered martensite with ≤15% ferrite **3. Hardness Uniformity:** - **Surface to Center:** ≤3 HRC variation - **Lot-to-Lot Consistency:** ±2 HRC - **Verification:** Multiple points on representative samples **4. Non-Destructive Testing:** - **Magnetic Particle:** For surface defects - **Ultrasonic:** For internal quality (if specified) ### **Certification Requirements:** - Chemistry certification to SAE J404 - Heat treatment cycle documentation - Mechanical test reports - Dimensional inspection reports - Microstructure analysis (if specified) --- ## **9. Design & Engineering Considerations** ### **Optimal Design Parameters:** - **Section Size:** 20-30mm diameter optimal - **Stress Concentrations:** Generous fillets (R ≥ 2mm) - **Surface Finish:** Critical for fatigue applications - **Tolerances:** Can be held tightly due to processing sequence ### **Fatigue Design Values:** - **Endurance Limit (fully reversed):** 450-550 MPa - **Surface Factor (Ka):** 0.9 (good surface finish) - **Size Factor (Kb):** 0.85 for 25mm diameter - **Reliability Factor (Kc):** 0.814 for 99% reliability ### **Manufacturing Considerations:** - **Secondary Operations:** Can be performed after final heat treatment - **Joining:** Limited welding capability; specialized procedures required - **Surface Treatments:** Can be plated or coated as needed - **Assembly:** Good for press fits and interference fits --- ## **10. Comparison with Alternative Materials & Processes** ### **Alternative 1: Conventional Through-Hardening** - **Process:** Austenitize at 870°C, quench, temper - **Result:** Higher hardness (45-52 HRC) but lower toughness - **Distortion:** Significant, requires grinding - **Application:** Higher wear resistance needed ### **Alternative 2: Normalize & Temper** - **Process:** Normalize at 900°C, temper - **Result:** Lower strength (800-1000 MPa) but better machinability - **Application:** Less critical components ### **Alternative 3: Induction Hardening** - **Process:** Localized surface hardening - **Result:** Hard surface with soft core - **Application:** Specific wear areas only ### **Why Choose This Process:** - **When:** Dimensional precision is critical - **When:** Core properties more important than surface hardness - **When:** Minimizing post-heat treatment machining is essential - **When:** Good toughness with moderate strength is required --- ## **11. Technical Notes & Special Considerations** ### **Metallurgical Rationale:** The intercritical reheating to 775°C creates a dual-phase structure that refines the final martensite grain size. This provides: - **Improved toughness** compared to conventional through-hardening - **Better fatigue crack initiation resistance** - **More uniform properties** through the section ### **Production Economics:** - **Tooling:** Standard tooling can be used - **Scrap Rate:** Lower due to dimensional stability - **Energy Use:** Reduced compared to full carburizing - **Lead Time:** Shorter processing cycle ### **Environmental Impact:** - **Energy Efficiency:** Reduced energy consumption (lower temperatures) - **Waste Reduction:** No grinding sludge from case removal - **Chemical Usage:** No carburizing gases required --- ## **12. Storage & Handling** ### **Post-Processing Handling:** - **Cleaning:** Remove all oils and contaminants - **Protection:** Apply rust preventive if not immediately used - **Storage:** Dry, temperature-controlled environment - **Handling:** Use protective coatings on precision surfaces ### **Quality Preservation:** - **Shelf Life:** Indefinite with proper storage - **Re-inspection:** Recommended after extended storage - **Re-work:** Limited capability due to final dimensions --- **Technical Significance:** This specific processing of AISI 5120 represents an innovative approach to achieving optimal core properties for case-hardening steels without the complications of actual carburizing. It is particularly valuable for applications where dimensional precision cannot be compromised by the distortion inherent in conventional carburizing processes. **Revision:** 1.0 **Date:** October 2023 **Disclaimer:** This specification describes material processed under specific conditions. Variations in processing parameters, section size, or alloy composition may significantly alter the resultant properties. Always conduct application-specific testing and consult with metallurgical engineers for critical applications. The described process requires precise control of all thermal cycles to achieve consistent results. -:- For detailed product information, please contact sales. -: AISI 5120 Steel, heat treated, machined to 25 mm, pseudocarburized, reheated to 775°C (1430°F), 150°C (300°F) temper Specification Dimensions Size： Diameter 20-1000 mm Length <4110 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 5120 Steel, heat treated, machined to 25 mm, pseudocarburized, reheated to 775°C (1430°F), 150°C (300°F) temper Properties -:- For detailed product information, please contact sales. -:

Applications of AISI 5120 Steel Flange, heat treated, machined to 25 mm, pseudocarburized, reheated to 775°C (1430°F), 150°C (300°F) temper -:- For detailed product information, please contact sales. -: Chemical Identifiers AISI 5120 Steel Flange, heat treated, machined to 25 mm, pseudocarburized, reheated to 775°C (1430°F), 150°C (300°F) temper -:- For detailed product information, please contact sales. -:

Packing of AISI 5120 Steel Flange, heat treated, machined to 25 mm, pseudocarburized, reheated to 775°C (1430°F), 150°C (300°F) temper -:- 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 581 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