AISI 4817 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 4817 Steel Flange Product Information -:- For detailed product information, please contact sales. -: AISI 4817 Steel Flange Synonyms -:- For detailed product information, please contact sales. -:

AISI 4817 Steel Product Information -:- For detailed product information, please contact sales. -: # **AISI 4817 Alloy Steel (UNS G48170)** ## **Medium Carbon Nickel-Molybdenum Case-Hardening Steel with Premium Toughness** --- ### **1. PRODUCT OVERVIEW** **AISI 4817 Alloy Steel (UNS G48170)** - **Material Classification:** Medium-carbon nickel-molybdenum alloy steel - **Primary Application:** Case hardening (carburizing or carbonitriding) - **Carbon Content:** 0.15-0.20% (optimal for deep case formation) - **Key Alloying Elements:** Nickel (3.25-3.75%) + Molybdenum (0.20-0.30%) - **Material Family:** AISI/SAE 48xx series (high-nickel molybdenum steels) - **"17" Designation:** Nominal carbon content of 0.17% - **UNS Designation:** G48170 (Standard), H48170 (Hardenability controlled) - **Premium Feature:** Exceptionally high core toughness due to 3.5% nickel content - **Typical Forms:** Bars, forgings, billets, tubing for critical components **Material Characteristics:** 1. **Superior Core Toughness:** 3.5% nickel provides exceptional impact resistance 2. **Deep Case Capability:** Low carbon allows deep carburizing without core brittleness 3. **Excellent Fatigue Performance:** Ideal for high-stress, fatigue-critical applications 4. **Good Hardenability:** Suitable for large section sizes 5. **Premium Cost:** Higher nickel content increases material cost but delivers exceptional performance --- ### **2. CHEMICAL COMPOSITION SPECIFICATION** | Element | AISI 4817 Standard Range (%) | Typical Aim Composition (%) | Metallurgical Function | |---------|-----------------------------|-----------------------------|------------------------| | **Carbon (C)** | 0.15-0.20 | 0.16-0.18 | Base strength, optimized for deep case formation | | **Manganese (Mn)** | 0.40-0.70 | 0.50-0.60 | Enhances hardenability, controls sulfur | | **Phosphorus (P)** | ≤ 0.035 | ≤ 0.020 | Residual impurity (strictly controlled) | | **Sulfur (S)** | ≤ 0.040 | 0.020-0.035 | Machinability enhancer (controlled levels) | | **Silicon (Si)** | 0.15-0.30 | 0.20-0.25 | Deoxidizer, solid solution strengthening | | **Nickel (Ni)** | 3.25-3.75 | 3.40-3.60 | **Primary alloy:** Provides exceptional toughness and hardenability | | **Molybdenum (Mo)** | 0.20-0.30 | 0.22-0.27 | **Secondary alloy:** Grain refinement, prevents temper embrittlement | | **Chromium (Cr)** | - | ≤ 0.20 | Trace residual (not specified but typically present) | | **Copper (Cu)** | - | ≤ 0.35 | Trace residual | | **Aluminum (Al)** | - | 0.020-0.040 | Grain size control (typically added) | | **Iron (Fe)** | Balance | Balance | Matrix element | **Composition Design Philosophy:** - **Carbon Optimization:** 0.17% nominal allows very deep case formation (>2mm possible) - **Nickel Premium:** 3.5% nominal provides aerospace-grade toughness - **Molybdenum Addition:** Ensures fine grain structure and tempering stability - **Economic Consideration:** Premium material justified for critical applications only - **Balance:** Optimized for maximum toughness with good case hardening response **High Nickel Advantages:** 1. **Exceptional Toughness:** Charpy impact values 2-3× higher than 8600 series 2. **Low Temperature Performance:** Maintains toughness down to -50°C (-60°F) 3. **Fatigue Crack Resistance:** Slows crack propagation significantly 4. **Distortion Control:** Reduces transformation stresses during heat treatment --- ### **3. INTERNATIONAL STANDARDS & EQUIVALENTS** | Standard System | Designation | Title / Description | Notes | |----------------|-------------|---------------------|-------| | **UNS** | G48170 | Unified Numbering System | Primary US designation | | **AISI/SAE** | 4817 | SAE J404, J412 | Original specification | | **ASTM** | A322 | Standard Specification for Steel Bars, Alloy | Grade 4817 | | **ASTM** | A29/A29M | Steel Bars, Carbon and Alloy | General requirements | | **ASTM** | A534 | Carburizing Steels for Anti-Friction Bearings | Bearing quality available | | **AMS** | 6281 | Steel Bars and Forgings, 3.5Ni-0.25Mo (0.15-0.20C) | Aerospace specification | | **ISO** | 683-11 | Heat-treatable steels | 17NiCrMo6-4 equivalent | | **DIN** | 1.6567 | 17NiCrMo6-4 | German equivalent | | **EN** | 1.6567 | 17NiCrMo6-4 | European designation | | **JIS** | SNCM420 | Nickel-chromium-molybdenum steel | Japanese similar grade | | **GB** | 17Ni2Mo | Chinese standard | Chinese equivalent | **H-Grade Availability:** - **AISI 4817H:** Hardenability controlled version - **Complies with:** SAE J1268 and ASTM A304 - **Typical bands:** Bands 2-4 depending on application - **Special versions:** Enhanced cleanliness for aerospace applications **Industry-Specific Standards:** - **Aerospace:** AMS 6281 with additional testing requirements - **Bearing Industry:** Modified versions for large bearing applications - **Oil & Gas:** Special requirements for sour service applications - **Defense:** MIL-S specifications for military components --- ### **4. PHYSICAL PROPERTIES** | Property | Value | Conditions / Notes | |----------|-------|-------------------| | **Density** | 7.85 g/cm³ (0.284 lb/in³) | At 20°C | | **Melting Range** | 1480-1520°C | Liquidus to solidus temperature | | **Thermal Conductivity** | 41.5 W/m·K | At 100°C, annealed condition | | **Specific Heat Capacity** | 460 J/kg·K | At 20°C | | **Coefficient of Thermal Expansion** | 12.2 × 10⁻⁶/K | 20-100°C temperature range | | **Electrical Resistivity** | 0.23 μΩ·m | At 20°C | | **Modulus of Elasticity** | 205 GPa (29.7×10⁶ psi) | Typical for steel | | **Shear Modulus** | 80 GPa (11.6×10⁶ psi) | - | | **Poisson's Ratio** | 0.29 | Standard value for steel | | **Magnetic Properties** | Ferromagnetic | Below Curie temperature (~770°C) | **Transformation Temperatures:** - **Ac₁:** ~730°C (1345°F) - **Ac₃:** ~800°C (1470°F) - **Ms (Martensite Start):** ~360°C (680°F) for core composition - **Mf (Martensite Finish):** ~210°C (410°F) for core composition - **Case Ms:** ~180°C (355°F) after carburizing to 0.8% C **Thermal Processing Characteristics:** - **Slow Austenitizing:** Benefits from longer soak times due to nickel content - **Controlled Quenching:** Oil quench sufficient for large sections - **Tempering Response:** Good stability with molybdenum addition - **Distortion Control:** Nickel reduces transformation stresses --- ### **5. MECHANICAL PROPERTIES** #### **As-Annealed Properties (For Machining):** | Property | Value Range | Testing Standard | Application Significance | |----------|-------------|------------------|--------------------------| | **Hardness** | 149-197 HB (85-93 HRB) | ASTM E10 | Optimized for machinability | | **Tensile Strength** | 500-650 MPa (73-94 ksi) | ASTM E8/E8M | Adequate for pre-hardening handling | | **Yield Strength (0.2%)** | 350-450 MPa (51-65 ksi) | ASTM E8/E8M | Sufficient for fixturing and assembly | | **Elongation in 4D** | 25-30% | ASTM E8/E8M | Excellent ductility for forming | | **Reduction of Area** | 50-60% | ASTM E8/E8M | High energy absorption capacity | | **Machinability Rating** | 60-65% of B1112 steel | Comparative | Moderate due to nickel content | #### **After Case Hardening (Typical):** *Carburize at 925°C, Oil Quench from 820°C, Temper at 175°C* | Property | Case Region | Core Region | Premium Feature | |----------|-------------|-------------|-----------------| | **Hardness** | 58-63 HRC | 35-42 HRC | Case similar to other grades | | **Tensile Strength** | - | 1000-1200 MPa | High due to nickel | | **Yield Strength** | - | 850-1050 MPa | Excellent for heavy loads | | **Elongation** | - | 12-18% | Good ductility | | **Charpy V-Notch Impact** | 10-20 J | **50-80 J** | **Exceptional toughness** | | **Fatigue Strength** | 600-700 MPa | - | Superior to lower-nickel grades | #### **Core Properties by Tempering Temperature:** | Tempering Temperature | Core Hardness (HRC) | Core UTS (MPa) | Core Impact Energy (J) | Nickel Benefit | |----------------------|---------------------|----------------|-----------------------|----------------| | **150°C (300°F)** | 38-42 | 1200-1400 | 55-75 | **Exceptional** | | **200°C (390°F)** | 36-40 | 1100-1300 | 60-85 | **Superior** | | **315°C (600°F)** | 32-36 | 950-1150 | 65-95 | **Outstanding** | | **425°C (800°F)** | 28-32 | 850-1000 | 70-105 | **Premium** | #### **Low Temperature Toughness (Core):** | Temperature | Charpy V-Notch Impact (J) | Retention vs 20°C | |-------------|----------------------------|-------------------| | **20°C (68°F)** | 50-80 | 100% | | **0°C (32°F)** | 45-75 | 85-95% | | **-20°C (-4°F)** | 40-70 | 75-90% | | **-40°C (-40°F)** | 35-65 | 65-85% | | **-60°C (-76°F)** | 30-55 | 55-75% | --- ### **6. CASE HARDENING CHARACTERISTICS** #### **Carburizing Response:** - **Optimal Carburizing Temperature:** 900-930°C (1650-1710°F) - **Case Depth Capability:** Up to 2.5mm (0.100") for heavy-duty applications - **Surface Carbon Content:** 0.75-0.90% achievable - **Case Hardness:** 58-63 HRC after proper heat treatment - **Effective Case Depth:** To 550 HV (50 HRC) typically 0.8-2.0mm #### **Hardenability Data (Jominy Test - Typical):** | Distance from Quenched End | Hardness (HRC) | Microstructure | Nickel Enhancement | |----------------------------|----------------|---------------|-------------------| | **1.5 mm (1/16 inch)** | 42-48 | 85-95% martensite | Significant | | **5 mm (3/16 inch)** | 38-44 | 75-90% martensite | Noticeable | | **10 mm (3/8 inch)** | 34-40 | 60-80% martensite | Moderate | | **15 mm (5/8 inch)** | 30-36 | 45-70% martensite | Present | | **25 mm (1 inch)** | 26-32 | 30-55% martensite | Still effective | #### **Through-Hardening Capability:** - **Maximum Section for Through-Hardening:** ~75mm (3 inches) diameter in oil - **Ideal Critical Diameter (Dᵢ):** ~55-70mm in oil quench - **Large Section Advantage:** Maintains better core properties than lower-nickel grades - **Quenching Flexibility:** Can use slower quenches for complex shapes #### **Deep Case Applications:** - **Very Deep Case:** >1.5mm for extreme contact stress applications - **Core Support:** High nickel ensures core supports deep case without yielding - **Gradient Control:** Nickel allows smoother case-core transition - **Distortion Management:** Better for deep case due to reduced transformation stress --- ### **7. TYPICAL APPLICATIONS** #### **Aerospace and Defense (Primary Market):** - **Helicopter Transmission Components:** Gears, pinions, shafts - **Aircraft Landing Gear:** Critical pins, bushings, actuation components - **Jet Engine Accessory Drives:** Gearbox components, drive shafts - **Military Vehicle Components:** Tank transmission gears, heavy-duty bearings - **Missile System Components:** Actuator gears, guidance mechanism parts #### **Energy Sector Critical Components:** - **Wind Turbine Gearboxes:** Planetary gears, high-speed shafts - **Gas Turbine Accessory Drives:** Critical gearing systems - **Oil & Gas Drilling Equipment:** Heavy-duty gear sets, bearing components - **Nuclear Power Plant Components:** Safety-critical gearing systems - **Hydroelectric Turbine Components:** Large gear sets, drive systems #### **Heavy Industrial Equipment:** - **Mining Equipment:** Crusher gears, conveyor drive components - **Steel Mill Equipment:** Roller table drives, heavy-duty gearboxes - **Marine Propulsion:** Reduction gears for large vessels - **Crane and Hoist Systems:** Critical gearing components - **Heavy Construction Equipment:** Final drive components, swing mechanisms #### **Transportation Critical Systems:** - **Railway Traction Systems:** Gearbox components for locomotives - **Heavy Truck Transmissions:** High-torque gear sets - **Marine Transmission Systems:** Reduction gears for workboats - **Special Vehicle Components:** Racing transmission gears, extreme-duty applications #### **Premium Industrial Applications:** - **Large Bearing Components:** Races for extreme-load bearings - **Heavy-Duty Gearboxes:** For cement, mining, and heavy industry - **Press and Forging Equipment:** Critical drive components - **Test Equipment Components:** For high-load fatigue testing machines - **Research and Development:** Material studies for extreme conditions --- ### **8. PROCESSING CHARACTERISTICS** #### **Machinability (Annealed Condition):** - **Relative Rating:** 60-65% of B1112 free-cutting steel - **Nickel Effect:** Work hardening tendency requires sharp tools and positive geometry - **Optimum Cutting Parameters:** - Cutting speed: 35-55 m/min for HSS tools - Cutting speed: 70-110 m/min for carbide tools - Feed rate: 0.15-0.25 mm/rev for roughing - Depth of cut: 2-4 mm optimal for chip control - Tool materials: Carbide with tough grade recommended - **Coolant Requirement:** Essential for heat control and chip evacuation - **Surface Finish:** Good (1.6-3.2μm Ra achievable with proper techniques) #### **Forming and Forging:** - **Hot Working Temperature:** 1150-900°C (2100-1650°F) - **Forgeability:** Good - suitable for most forging operations - **Cold Formability:** Fair in annealed condition - **Annealing Between Operations:** Recommended for severe deformation - **Forging Advantage:** Nickel reduces cracking tendency during forging #### **Welding Characteristics:** - **Weldability Rating:** Fair to Poor (requires significant precautions) - **Preheat Temperature:** 200-300°C (400-570°F) minimum - **Post-Weld Heat Treatment:** Stress relief at 590-650°C (1100-1200°F) mandatory - **Recommended Methods:** GTAW (TIG) with matching filler - **Filler Material:** AWS E12018-D2 or matching high-nickel composition - **Critical Consideration:** High nickel increases hot cracking susceptibility #### **Grinding After Case Hardening:** - **Surface Region:** Requires CBN or diamond wheels - **Heat Generation Control:** Critical to avoid tempering - **Wheel Selection:** Fine grit for finish, coarser for stock removal - **Coolant Application:** Copious flow essential - **Dressing Frequency:** Regular to maintain wheel sharpness --- ### **9. HEAT TREATMENT RECOMMENDATIONS** #### **Standard Case Hardening Process:** 1. **Carburizing:** - Temperature: 910-930°C (1670-1710°F) - Atmosphere: Endothermic gas with precise carbon control - Carbon Potential: 0.80-0.90% - Time: Varies with desired case depth (typically 6-24 hours) 2. **Quenching Options:** - Direct Quench: From carburizing temperature (for simple shapes) - Reheat Quench: Cool, reheat to 815-835°C (1500-1535°F), then quench - Medium: Oil quench recommended for most applications - Agitation: Moderate to ensure uniform cooling 3. **Tempering:** - Temperature: 150-200°C (300-400°F) - Time: 1-2 hours minimum, longer for thick sections - Purpose: Stress relief, retained austenite stabilization 4. **Optional Treatments:** - Sub-zero treatment: To transform retained austenite (-70°C to -100°C) - Shot peening: For improved fatigue resistance - Stress relieving: Additional treatment if machining after hardening #### **Annealing for Machining:** - **Full Annealing:** 830-850°C (1525-1560°F), furnace cool at 20°C/hour to 600°C - **Process Annealing:** 650-700°C (1200-1300°F), air cool - **Spheroidize Annealing:** 730-750°C (1350-1380°F), slow cool at 10°C/hour - **Resulting Hardness:** 149-197 HB (optimal for machining) #### **Special Considerations for 4817:** - **Longer Austenitizing:** Nickel requires longer soak times for complete transformation - **Controlled Cooling:** Benefits from controlled cooling rates due to hardenability - **Tempering Stability:** Molybdenum ensures good tempering resistance - **Distortion Control:** Nickel reduces distortion compared to lower-nickel grades --- ### **10. MICROSTRUCTURAL CHARACTERISTICS** #### **As-Annealed Condition:** - **Matrix:** Ferrite with spheroidized carbides - **Grain Size:** ASTM 5-7 (fine to medium) - **Carbide Distribution:** Uniformly dispersed fine carbides - **Band Structure:** Minimal due to controlled processing #### **After Case Hardening:** | Region | Microstructure | Characteristics | Nickel Benefit | |--------|---------------|-----------------|----------------| | **Surface Case** | High-carbon martensite + carbides | Hardness: 58-63 HRC, Retained austenite: 15-30% | Fine carbide distribution | | **Transition Zone** | Mixed martensite structures | Gradual hardness decrease | Smooth transition | | **Core** | Low-carbon martensite/bainite | **Exceptional toughness**, Hardness: 35-42 HRC | **Nickel provides superior microstructure** | #### **Grain Structure Advantages:** - **Fine Grain:** Molybdenum promotes austenite grain refinement - **Uniform Transformation:** Nickel ensures consistent response - **Clean Interface:** Smooth case-core transition - **Microcleanliness:** Typically high quality for premium applications #### **Retained Austenite Management:** - **Typical Level:** 15-30% in case after quenching - **Stabilization:** Nickel stabilizes austenite - **Control Methods:** Sub-zero treatment, tempering, shot peening - **Optimization:** Balance between toughness and dimensional stability --- ### **11. QUALITY ASSURANCE AND TESTING** #### **Standard Testing Requirements:** 1. **Chemical Analysis:** Spectrographic analysis per heat/lot (ASTM E415) 2. **Mechanical Testing:** Tensile and hardness tests (ASTM E8, E18) 3. **Impact Testing:** Charpy V-notch at multiple temperatures (ASTM E23) 4. **Microstructural Examination:** Grain size, cleanliness (ASTM E112, E45) 5. **Hardenability Testing:** For H-grades per ASTM A255 6. **Non-Destructive Testing:** UT, MPI as required by specification #### **Premium Testing for Critical Applications:** - **Fracture Toughness Testing:** KIC or JIC per ASTM E399/E1820 - **Fatigue Testing:** S-N curves, crack growth rates - **Residual Stress Analysis:** XRD measurement per ASTM E915 - **Cleanliness Rating:** Advanced inclusion assessment - **Macroetch Evaluation:** For segregation and soundness #### **Inclusion Rating (Typical for Premium Quality):** | Inclusion Type | ASTM E45 Rating (Worst Field) | Typical Premium Value | |----------------|-------------------------------|-----------------------| | **A (Sulfide)** | ≤ 1.5 | 0.5-1.0 | | **B (Alumina)** | ≤ 1.0 | 0.5 max | | **C (Silicate)** | ≤ 1.0 | 0.5 max | | **D (Globular Oxide)** | ≤ 1.0 | 0.5 max | #### **Certification Levels:** - **Standard Mill Certificate:** Chemical composition and hardness - **Test Certificate 3.1:** Includes mechanical property testing - **Premium Certificate 3.2:** Comprehensive testing including impact properties - **Aerospace Certification:** AMS 6281 compliance with additional testing - **H-Grade Certification:** Includes Jominy hardenability curve --- ### **12. COMPARISON WITH SIMILAR GRADES** #### **Comparison with Other High-Performance Grades:** | Grade | Ni% Range | C% Range | Core Toughness (J) | Relative Cost | Primary Advantage | |-------|-----------|----------|-------------------|---------------|-------------------| | **AISI 4817** | 3.25-3.75 | 0.15-0.20 | **50-80** | 100 | Optimal balance for extreme toughness | | **AISI 9310** | 3.00-3.50 | 0.08-0.13 | 55-85 | 120 | Aerospace standard, slightly higher toughness | | **AISI 4820** | 3.25-3.75 | 0.18-0.23 | 45-75 | 105 | Higher carbon for larger sections | | **AISI 4320** | 1.65-2.00 | 0.17-0.22 | 40-60 | 70 | Cost-effective alternative | | **AISI 8620** | 0.40-0.70 | 0.18-0.23 | 30-50 | 50 | General purpose, lower cost | #### **Performance Comparison Table:** | Property | 4817 | 9310 | 4320 | 8620 | 4817 Advantage | |----------|------|------|------|------|----------------| | **Core Toughness** | 95 | 100 | 75 | 60 | Excellent, near premium | | **Case Hardness** | 95 | 95 | 95 | 90 | Equal to best | | **Fatigue Strength** | 90 | 95 | 80 | 70 | Very good | | **Cost Effectiveness** | 80 | 70 | 90 | 100 | Premium but justified | | **Large Section Capability** | 90 | 85 | 80 | 70 | Very good | | **Low Temperature Performance** | 95 | 100 | 70 | 50 | Exceptional | #### **Selection Guidelines:** - **Choose 4817 over 9310:** For cost-sensitive critical applications - **Choose 4817 over 4320:** When maximum toughness is required - **Choose 4817 over 8620:** For extreme-duty or safety-critical applications - **Choose 4817 over 4820:** For deeper case applications with maximum toughness - **Consider H-grade (4817H):** When hardenability consistency is critical #### **Cost-Performance Analysis:** | Application Level | Recommended Grade | Justification | |------------------|-------------------|---------------| | **General Purpose** | 8620 | Cost-effective for non-critical applications | | **Medium Duty** | 4320 | Good balance of cost and performance | | **Heavy Duty** | 4817 | Premium performance for critical applications | | **Aerospace Critical** | 9310 | Industry standard for aerospace | | **Extreme Conditions** | 4817 | Where 9310 cost cannot be justified | --- ### **13. DESIGN CONSIDERATIONS** #### **Optimal Design Parameters for 4817 Components:** 1. **Case Depth Recommendations:** - Standard duty: 0.5-1.0mm case depth - Heavy duty: 1.0-1.5mm case depth - Extreme duty: 1.5-2.5mm case depth (utilizes deep case capability) - Maximum practical: Up to 3.0mm for very large components 2. **Core Size Considerations:** - Minimum core size: Should be ≥2.5× case depth for deep cases - Optimal core hardness: 35-40 HRC for most applications - Core strength: Exceptionally high due to nickel content 3. **Geometry Guidelines:** - Generous fillet radii (minimum = case depth × 1.5) - Gradual section changes to minimize stress concentrations - Symmetrical designs to leverage nickel's distortion control - Adequate machining allowance: 0.2-0.4mm per side for post-hardening grinding #### **Fatigue Design Factors:** - **Surface Finish:** Critical for fatigue life (Ra < 0.8μm recommended) - **Residual Stresses:** Compressive stresses from case hardening beneficial - **Shot Peening:** Can increase fatigue life by 30-100% - **Case-Core Interface:** Smooth transition reduces stress concentrations #### **Large Component Design:** - **Section Size Capability:** Up to 200mm diameter for case hardening - **Through-Hardening:** Up to 75mm diameter possible - **Distortion Control:** Nickel reduces distortion in large, complex shapes - **Quenching Considerations:** Oil quench sufficient for most sizes --- ### **14. ENVIRONMENTAL AND ECONOMIC CONSIDERATIONS** #### **Cost Factors:** - **Material Cost:** High (3-4× 8600 series due to nickel content) - **Processing Cost:** Similar to other case-hardening grades - **Lifecycle Cost:** Excellent for critical applications (extended service life) - **Failure Cost:** Justified by preventing catastrophic failures - **Availability:** Limited to specialty steel producers #### **Environmental Aspects:** - **Recyclability:** 100% recyclable as nickel-alloy steel scrap - **Production Energy:** High due to nickel mining and refining - **Carbon Footprint:** Higher than lower-alloy steels - **Sustainability:** Nickel is fully recyclable but energy-intensive to produce - **Alternative Materials:** Consider lower-nickel grades for less critical applications #### **Supply Chain Considerations:** - **Lead Times:** Longer than standard grades (8-16 weeks typical) - **Global Availability:** Limited number of qualified producers - **Quality Consistency:** Requires strict supplier qualification - **Certification Requirements:** Extensive documentation needed - **Stock Availability:** Typically made-to-order rather than stock items #### **Total Cost of Ownership Analysis:** | Cost Component | 4817 vs 8620 | Justification | |----------------|--------------|---------------| | **Initial Material Cost** | 300-400% higher | Nickel content premium | | **Processing Cost** | Similar | Same heat treatment processes | | **Inspection Cost** | Similar or lower | Better consistency may reduce inspection | | **Failure Rate** | Significantly lower | Superior toughness reduces failures | | **Maintenance Cost** | Lower | Longer service intervals | | **Downtime Cost** | Much lower | Reduced unexpected failures | | **Total Lifecycle Cost** | Often lower | For critical applications | --- ### **15. TECHNICAL GUIDELINES** #### **Optimal Processing Sequence:** 1. **Material Selection:** Choose 4817 for applications requiring extreme toughness 2. **Design:** Incorporate adequate case depth and proper geometries 3. **Machining:** Complete all heavy machining in annealed condition 4. **Heat Treatment:** Follow recommended carburizing and hardening cycles 5. **Finishing:** Grind, hone, or superfinish as required 6. **Quality Verification:** Comprehensive testing including impact properties 7. **Documentation:** Maintain full traceability for critical applications #### **Troubleshooting Common Issues:** | Problem | Possible Cause | Solution for 4817 | |---------|---------------|-------------------| | **Excessive Retained Austenite** | High carbon, rapid quench | Sub-zero treatment, double temper | | **Insufficient Case Depth** | Low carbon potential, short time | Increase carbon potential, extend time | | **Core Too Hard** | Excessive carbon pickup | Better atmosphere control, shorter time | | **Distortion** | Uneven heating/cooling | Use fixtures, slower heating rates | | **Cracking** | Quench too severe, design issues | Use milder quenchant, redesign sharp corners | | **Poor Machinability** | Incorrect annealing | Ensure proper spheroidize annealing | #### **Special Considerations for 4817:** - **Nickel Segregation:** Monitor for banding in large sections - **Austenitizing Time:** Allow extra time for complete transformation - **Tempering Response:** May require higher tempering temperatures for certain hardness - **Weld Repair:** Generally not recommended after case hardening - **Storage:** Protect from corrosion during storage and handling --- **TECHNICAL SUMMARY:** AISI 4817 (UNS G48170) represents a premium nickel-molybdenum case-hardening steel designed for applications requiring exceptional toughness and reliability. With its high nickel content (3.25-3.75%) and optimal carbon level (0.15-0.20%), it delivers superior impact resistance, excellent fatigue performance, and good deep-case capability. While significantly more expensive than standard case-hardening grades, 4817 provides unmatched performance for safety-critical and extreme-duty applications where failure is not an option. **KEY ADVANTAGES:** 1. **Exceptional Toughness:** 2-3× higher impact resistance than 8600 series 2. **Superior Fatigue Performance:** Excellent resistance to crack initiation and growth 3. **Deep Case Capability:** Suitable for very deep case applications (>2mm) 4. **Large Section Performance:** Maintains properties in heavy sections 5. **Low Temperature Capability:** Maintains toughness to -50°C and below **APPLICATION RECOMMENDATION:** AISI 4817 is recommended for: - Aerospace and defense critical components - Energy sector extreme-duty applications - Heavy industrial equipment where downtime is costly - Safety-critical systems where failure is catastrophic - Applications requiring certification to premium standards - Components subject to impact loading at low temperatures --- **QUALITY ASSURANCE STATEMENT:** AISI 4817 alloy steel is produced to meet or exceed the requirements of SAE J404/J412 and ASTM A322. For critical applications, premium quality with enhanced cleanliness and comprehensive testing is available. H-grade material (4817H) provides guaranteed hardenability for applications requiring maximum consistency. Aerospace quality material complying with AMS 6281 is available with additional testing and documentation requirements. **DISCLAIMER:** The information provided represents typical properties and characteristics based on standard specifications. Actual values may vary within acceptable specification ranges. For critical applications, material testing and validation are essential. Consultation with qualified materials engineering professionals is recommended for specific application requirements. Proper heat treatment procedures must be followed to achieve specified properties. The high nickel content makes this material significantly more expensive than standard case-hardening grades; cost-benefit analysis should be performed before specification. Always verify material certification and test reports upon receipt for critical applications. -:- For detailed product information, please contact sales. -: AISI 4817 Steel Specification Dimensions Size： Diameter 20-1000 mm Length <4086 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 4817 Steel Properties -:- For detailed product information, please contact sales. -:

Applications of AISI 4817 Steel Flange -:- For detailed product information, please contact sales. -: Chemical Identifiers AISI 4817 Steel Flange -:- For detailed product information, please contact sales. -:

Packing of AISI 4817 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 557 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