AISI 4720H 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 4720H Steel Flange Product Information -:- For detailed product information, please contact sales. -: AISI 4720H Steel Flange Synonyms -:- For detailed product information, please contact sales. -:

AISI 4720H Steel Product Information -:- For detailed product information, please contact sales. -: # **AISI 4720H Alloy Steel (UNS H47200)** ## **Hardenability Controlled Nickel-Chromium-Molybdenum Case-Hardening Steel** --- ### **1. PRODUCT OVERVIEW** **AISI 4720H Alloy Steel - Hardenability Controlled** - **Material Classification:** Medium-carbon nickel-chromium-molybdenum alloy steel with guaranteed hardenability - **Primary Application:** Case hardening for critical components requiring consistent performance - **H-Grade Designation:** Complies with SAE J1268/ASTM A304 hardenability requirements - **Carbon Content:** 0.18-0.23% (tightly controlled within narrow aim range) - **Key Alloy Feature:** Triple alloy system with controlled chemistry for predictable transformation - **UNS Designation:** H47200 (Hardenability controlled version) - **Quality Advantage:** Guaranteed case-core hardness gradient and consistent heat treatment response **Critical H-Grade Features:** - **Controlled Chemistry:** Elements adjusted to hit specific hardenability bands - **Mandatory Testing:** Each heat Jominy tested and certified - **Reduced Variability:** Lot-to-lot consistency within ±2 HRC - **Predictable Performance:** Accurate case depth and core hardness prediction - **Certified Quality:** Full traceability with hardenability curve documentation --- ### **2. CHEMICAL COMPOSITION SPECIFICATION (H-GRADE)** | Element | AISI 4720H Standard Range (%) | Typical Aim Composition (%) | H-Grade Control Significance | |---------|-----------------------------|-----------------------------|------------------------------| | **Carbon (C)** | 0.18-0.23 | 0.19-0.21 | Centered for consistent carburizing response; primary hardenability control | | **Manganese (Mn)** | 0.50-0.70 | 0.58-0.65 | Major hardenability element; fine-tuned per heat to hit band targets | | **Phosphorus (P)** | ≤ 0.025 | ≤ 0.015 | Tighter control than standard grade (0.035% max) | | **Sulfur (S)** | ≤ 0.025 | 0.015-0.020 | Tighter control than standard grade (0.040% max); optimized for machinability | | **Silicon (Si)** | 0.15-0.30 | 0.20-0.25 | Consistent deoxidation; minor hardenability effect | | **Nickel (Ni)** | 0.90-1.20 | 1.00-1.10 | Tightly controlled for consistent core toughness (±0.05% typical) | | **Chromium (Cr)** | 0.35-0.55 | 0.45-0.50 | Controlled for consistent hardenability and wear properties | | **Molybdenum (Mo)** | 0.15-0.25 | 0.18-0.22 | Grain refinement; controlled for tempering stability | | **Aluminum (Al)** | 0.020-0.050 | 0.030-0.040 | **Mandatory for H-grades:** Grain size control (ASTM 6-8 typical) | | **Copper (Cu)** | Report | ≤ 0.20 | Residual; monitored and reported | | **Chromium (Cr)** | Report | ≤ 0.20 | Residual; monitored and reported | | **Boron (B)** | Optional: 0.0005-0.003 | Optional | Hardenability enhancer (4720HB if specified) | **H-Grade Chemistry Control Philosophy:** 1. **Aim Chemistry:** Elements maintained at center of H-ranges for consistency 2. **Lot Adjustment:** Mn, C fine-tuned while staying within H-ranges to hit hardenability targets 3. **Residual Control:** Tighter limits on P, S, Cu for predictable behavior 4. **Mandatory Aluminum:** Ensures consistent grain size (ASTM 6-8) 5. **Reporting Requirement:** All residuals must be reported and controlled **Comparison: Standard 4720 vs. 4720H Chemistry Control** | Element | Standard 4720 | 4720H | Impact | |---------|---------------|-------|---------| | **P max** | 0.035% | 0.025% | Better machinability consistency | | **S max** | 0.040% | 0.025% | Improved hot workability | | **Al range** | Not specified | 0.020-0.050% | Consistent grain size | | **Testing** | Chemistry only | Chemistry + Jominy | Guaranteed performance | | **Traceability** | Heat number | Full heat history + Jominy curve | Complete quality record | --- ### **3. INTERNATIONAL STANDARDS & EQUIVALENTS** | Standard System | Designation | Title / Description | Hardenability Reference | |----------------|-------------|---------------------|--------------------------| | **UNS** | H47200 | Unified Numbering System | Includes hardenability requirement | | **SAE** | 4720H | SAE J1268 | Hardenability Bands for Hardenability Steels | | **ASTM** | A304 | Steel Bars, Alloy, Subject to End-Quench Hardenability | Primary H-grade specification | | **ASTM** | A29/A29M | Steel Bars, Carbon and Alloy | Includes H-grade requirements | | **AMS** | 6271H | Steel Bars and Forgings | Aerospace H-grade specification | | **ISO** | 683-11 | Heat-treatable steels | Includes H-designation requirements | | **DIN** | 1.6523H | 20NiCrMo2-2 H-güte | German H-grade equivalent | | **EN** | 1.6523H | 20NiCrMo2-2 H-grade | European H-designation | | **JIS** | - | Controlled hardenability grades | Similar specifications available | | **GB** | 20NiCrMoH | Chinese H-grade standard | Chinese equivalent | **Hardenability Band System (SAE J1268):** - **Available Bands:** Typically Bands 1-4 for 4720H - **Band Selection Criteria:** Based on section size and application requirements - **Common Selection:** Band 2 for general applications, Band 3 for heavier sections - **Certification:** Each heat supplied with actual Jominy curve showing band compliance **Industry-Specific Standards:** - **Automotive:** Often specified to OEM standards (Ford, GM, Chrysler, etc.) - **Aerospace:** AMS 6271H with additional cleanliness requirements - **Bearing Industry:** Modified versions for bearing applications - **Military:** MIL-S specifications for defense applications --- ### **4. HARDENABILITY SPECIFICATION (JOMINY TEST)** #### **Standard Hardenability Bands for AISI 4720H:** | Distance from Quenched End | Band 1 (HRC) | Band 2 (HRC) | Band 3 (HRC) | Band 4 (HRC) | |----------------------------|--------------|--------------|--------------|--------------| | **1.5 mm (1/16")** | 36-42 | 39-45 | 42-48 | 45-51 | | **5 mm (3/16")** | 32-38 | 35-41 | 38-44 | 41-47 | | **10 mm (3/8")** | 28-34 | 31-37 | 34-40 | 37-43 | | **15 mm (5/8")** | 25-31 | 28-34 | 31-37 | 34-40 | | **20 mm (3/4")** | 23-29 | 26-32 | 29-35 | 32-38 | | **25 mm (1")** | 21-27 | 24-30 | 27-33 | 30-36 | #### **Predicted Hardness for 25mm Round (Oil Quenched, Band 3):** | Position in 25mm Diameter | Hardness Range (HRC) | Microstructure % Martensite | Carbon Equivalent | |---------------------------|----------------------|----------------------------|-------------------| | **Surface** | 42-48 | 90-100% | ~0.45% | | **Mid-Radius** | 34-40 | 70-85% | ~0.35% | | **Center** | 27-33 | 40-60% | ~0.25% | | **Case Hardened Surface** | 58-63* | High-carbon martensite | 0.70-0.90%* | *After carburizing; core values shown are for through-hardened condition #### **Hardenability Consistency Guarantee:** - **Band Compliance:** Each heat guaranteed within specified band - **Hardness Variation:** ±2 HRC maximum across production lots - **Case Depth Predictability:** ±0.1mm effective case depth variation - **Core Hardness Consistency:** ±3 HRC maximum variation #### **Ideal Critical Diameter (Dᵢ) by Band:** | Band | Dᵢ in Oil Quench (mm) | Dᵢ in Water Quench (mm) | Typical Applications | |------|------------------------|--------------------------|---------------------| | **Band 1** | 35-45 | 55-65 | Small sections, light duty | | **Band 2** | 45-55 | 65-75 | General purpose | | **Band 3** | 55-65 | 75-85 | Medium sections, automotive | | **Band 4** | 65-75 | 85-95 | Heavy sections, industrial | --- ### **5. PHYSICAL PROPERTIES** | Property | Value | Conditions / Notes | |----------|-------|-------------------| | **Density** | 7.85 g/cm³ (0.284 lb/in³) | At 20°C, consistent across heats | | **Melting Range** | 1480-1520°C | Predictable due to controlled chemistry | | **Thermal Conductivity** | 42.5 W/m·K | At 100°C, annealed condition | | **Specific Heat Capacity** | 460 J/kg·K | At 20°C | | **Coefficient of Thermal Expansion** | 12.3 × 10⁻⁶/K | 20-100°C; consistent heat-to-heat (±5%) | | **Electrical Resistivity** | 0.22 μΩ·m | At 20°C | | **Modulus of Elasticity** | 205 GPa (29.7×10⁶ psi) | Consistent across all heats | | **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 (Guaranteed Consistency):** - **Ac₁:** 735±5°C (1355±10°F) - **Ac₃:** 805±5°C (1480±10°F) - **Ms (Core):** 380±5°C (715±10°F) - **Mf (Core):** 220±5°C (430±10°F) - **Ms (Case):** 180±5°C (355±10°F) after carburizing - **Mf (Case):** 0±10°C (32±20°F) after carburizing **Consistency Advantages:** 1. **Predictable Austenitizing:** Consistent temperature requirements 2. **Uniform Transformation:** Similar phase change kinetics across lots 3. **Controlled Distortion:** Predictable dimensional changes during heat treatment 4. **Repeatable Results:** Same heat treatment parameters yield same results --- ### **6. MECHANICAL PROPERTIES (GUARANTEED)** #### **As-Annealed Properties (Guaranteed Consistency):** | Property | Value Range | Consistency Guarantee | Testing Standard | |----------|-------------|------------------------|------------------| | **Hardness** | 149-197 HB | ±10 HB maximum variation | ASTM E10 | | **Tensile Strength** | 500-650 MPa | ±5% maximum variation | ASTM E8/E8M | | **Yield Strength (0.2%)** | 350-450 MPa | ±5% maximum variation | ASTM E8/E8M | | **Elongation in 4D** | 25-30% | ±2 percentage points | ASTM E8/E8M | | **Reduction of Area** | 50-60% | ±5 percentage points | ASTM E8/E8M | | **Machinability** | 65-70% of B1112 | Consistent tool life (±15%) | Comparative | #### **After Case Hardening (Guaranteed Minimums - Band 3):** *Carburize at 925°C, Oil Quench, Temper at 175°C* | Property | Case Region | Core Region | Consistency | |----------|-------------|-------------|------------| | **Hardness** | 58-63 HRC | 32-38 HRC | ±1.5 HRC case, ±2 HRC core | | **Tensile Strength** | - | ≥1000 MPa | ±5% | | **Yield Strength** | - | ≥850 MPa | ±5% | | **Charpy Impact** | ≥10 J | ≥40 J | ±15% | | **Effective Case Depth** | 0.5-1.5mm at 550 HV | - | ±0.1mm | #### **Core Properties by Tempering Temperature (Predictable):** | Tempering Temperature | Core Hardness (HRC) | Core UTS (MPa) | Core Impact (J) | Prediction Accuracy | |----------------------|---------------------|----------------|----------------|---------------------| | **150°C (300°F)** | 36-40 | 1200-1400 | 35-45 | ±2 HRC, ±5% UTS | | **200°C (390°F)** | 34-38 | 1100-1300 | 40-50 | ±2 HRC, ±5% UTS | | **315°C (600°F)** | 30-34 | 950-1150 | 45-60 | ±2 HRC, ±5% UTS | | **425°C (800°F)** | 26-30 | 850-1000 | 50-70 | ±2 HRC, ±5% UTS | #### **Fatigue Properties (Typical, Consistent):** - **Rotating Bending Fatigue Limit:** 550-650 MPa (core dependent) - **Contact Fatigue Strength (Case):** L₁₀ ~ 10⁷ cycles at 2000 MPa contact stress - **Gear Bending Fatigue:** Consistent S-N curve with minimal scatter - **Predictability:** Fatigue life variation reduced by 30-50% vs. standard grade --- ### **7. CASE HARDENING PERFORMANCE (PREDICTABLE)** #### **Carburizing Response Consistency:** - **Carbon Absorption Rate:** Consistent across heats (±5%) - **Case Depth Growth:** Predictable time-depth relationship - **Surface Carbon Control:** 0.75-0.85% achievable with standard practice - **Carbon Gradient:** Reproducible profile from surface to core #### **Effective Case Depth Prediction (Based on Jominy Data):** | Carburizing Time at 925°C | Predicted ECD (mm) | Prediction Accuracy | |---------------------------|---------------------|---------------------| | **4 hours** | 0.5-0.7 | ±0.05mm | | **8 hours** | 0.8-1.0 | ±0.08mm | | **12 hours** | 1.1-1.3 | ±0.10mm | | **16 hours** | 1.4-1.6 | ±0.12mm | *ECD = Effective Case Depth to 550 HV (50 HRC)* #### **Distortion Control Advantages:** 1. **Predictable Growth:** Consistent case expansion during carburizing 2. **Uniform Transformation:** Similar martensite formation across lots 3. **Controlled Warpage:** Reduced and predictable distortion patterns 4. **Machining Allowance:** Can be optimized based on predictable behavior --- ### **8. TYPICAL APPLICATIONS (H-GRADE SPECIFIC)** #### **Applications Requiring 4720H Consistency:** 1. **Automotive Transmission Components:** - Synchronizer hubs and rings (consistent engagement) - Gear sets (uniform load distribution, noise control) - Shift forks and selectors (reliable shifting performance) - *Requirement:* Interchangeability across production lots 2. **Aerospace Gearing Systems:** - Actuator gears (flight control reliability) - Landing gear mechanisms (safety-critical performance) - Engine accessory drives (certification requirements) - *Requirement:* Certification and traceability 3. **Industrial Gearboxes:** - High-speed gear sets (predictable fatigue life) - Heavy-duty mining gears (consistent wear resistance) - Precision reduction gears (minimal backlash variation) - *Requirement:* Reduced downtime, predictable maintenance 4. **Bearing Components:** - Bearing races (consistent contact fatigue life) - Roller bearings (uniform hardness profile) - Aerospace bearings (reliability in critical applications) - *Requirement:* L₁₀ life predictability 5. **Medical Equipment:** - Surgical instrument gears (sterilization cycle resistance) - Imaging system components (reliability in clinical settings) - Dental equipment (consistent performance) - *Requirement:* Regulatory compliance, patient safety #### **Economic Justification for H-Grade Premium:** | Cost Category | Standard 4720 | 4720H | Savings/Benefit | |---------------|---------------|-------|-----------------| | **Heat Treatment Scrap** | 3-5% | 1-2% | 2-3% reduction | | **Inspection Costs** | 100% testing | Statistical sampling | 40-60% reduction | | **Assembly Issues** | Occasional fit problems | Minimal | Reduced downtime | | **Warranty Claims** | Higher due to variability | Lower, predictable | 1-2% of part cost | | **Development Time** | Longer due to tuning | Shorter, predictable | 20-30% time savings | | **Total Cost Impact** | Higher hidden costs | Predictable, optimized | Better ROI | --- ### **9. PROCESSING CHARACTERISTICS** #### **Machinability (Annealed Condition - Consistent):** - **Relative Rating:** 65-70% of B1112 steel - **Tool Life Consistency:** ±15% variation vs ±30% for standard grade - **Recommended Parameters for 25mm Round:** - Cutting speed: 40-70 m/min (HSS), 80-130 m/min (carbide) - Feed rate: 0.15-0.30 mm/rev for roughing - Depth of cut: 2-5 mm optimal - Tool geometry: Positive rake angles recommended - **Chip Formation:** Consistent across material lots - **Surface Finish:** 1.6-3.2μm Ra easily achievable with consistent results #### **Heat Treatment Processing Advantages:** 1. **Reduced Parameter Adjustment:** Fewer heat treatment trials needed 2. **Consistent Soak Times:** Predictable austenitization requirements 3. **Uniform Quenching Response:** Similar cooling rate requirements 4. **Predictable Tempering:** Same tempering parameters yield same hardness #### **Welding Considerations (Pre-Hardening):** - **Weldability Rating:** Fair (similar to standard grade but more predictable) - **Preheat Requirement:** 150-200°C, consistent across heats - **HAZ Hardness:** Predictable hardness profiles - **Post-Weld Treatment:** Consistent response to stress relief - **Filler Recommendation:** AWS E10018-D2 or matching composition #### **Grinding After Case Hardening:** - **Consistent Grindability:** Similar wheel wear rates across lots - **Surface Integrity:** Predictable grinding burn sensitivity - **Dimensional Control:** Consistent growth/shrinkage during grinding - **Recommended Practice:** Use CBN wheels for hardened material --- ### **10. QUALITY ASSURANCE & CERTIFICATION** #### **Mandatory Testing for Each Heat of 4720H:** 1. **Complete Chemical Analysis:** - Spectrographic analysis (ASTM E415) - All elements including residuals - Carbon verification by combustion analysis 2. **Jominy End-Quench Test:** - ASTM A255 on each heat - Full curve with 12-15 data points - Band verification against SAE J1268 3. **Hardness Verification:** - Multiple points in annealed condition - Surface and core hardness if supplied heat treated 4. **Microstructural Examination:** - Grain size measurement (ASTM E112) - Inclusion rating (ASTM E45, typically Method D) - Microcleanliness assessment #### **Certification Package Includes:** - **Material Test Certificate 3.2:** EN 10204 compliant - **Jominy Hardenability Curve:** Actual test results with band compliance statement - **Chemical Analysis Report:** Full elemental breakdown - **Heat Treatment Record:** If supplied heat treated - **Traceability Documentation:** Complete material history - **Optional:** Microcleanliness report, macroetch photos, ultrasonic test results #### **Acceptance Criteria (Guaranteed):** | Parameter | Requirement | Measurement Method | Tolerance | |-----------|-------------|-------------------|-----------| | **Chemistry** | Within H-grade ranges | Spectrographic | Per SAE J404 | | **Jominy Band** | Within specified band | ASTM A255 | Full compliance | | **Annealed Hardness** | 149-197 HB | Brinell/Rockwell B | ±10 HB | | **Grain Size** | ASTM 6-8 | ASTM E112 | ±1 number | | **Inclusion Rating** | As specified | ASTM E45 | Per customer requirement | #### **Statistical Process Control Advantages:** - **Reduced Testing:** Statistical sampling possible due to consistency - **Process Capability:** Higher Cpk values achievable - **Quality Metrics:** Consistent performance metrics - **Supplier Management:** Easier qualification and monitoring --- ### **11. COMPARISON WITH OTHER H-GRADES** | H-Grade | C% Range | Ni% Range | Cr% Range | Mo% Range | Typical Band | Relative Cost | Best Application | |---------|----------|-----------|-----------|-----------|--------------|---------------|------------------| | **4720H** | 0.18-0.23 | 0.90-1.20 | 0.35-0.55 | 0.15-0.25 | Band 2-3 | 100 | Balanced general applications | | **8620H** | 0.18-0.23 | 0.40-0.70 | 0.40-0.60 | 0.15-0.25 | Band 2-3 | 85 | Cost-sensitive automotive | | **4320H** | 0.17-0.22 | 1.65-2.00 | 0.40-0.60 | 0.20-0.30 | Band 2-3 | 120 | High-toughness applications | | **9310H** | 0.08-0.13 | 3.00-3.50 | 1.00-1.40 | 0.08-0.15 | Band 3-4 | 160 | Premium aerospace | | **5120H** | 0.17-0.22 | - | 0.70-0.90 | - | Band 1-2 | 75 | Low-cost general purpose | #### **Selection Matrix for Critical Applications:** | Primary Requirement | Recommended H-Grade | Reason | |---------------------|---------------------|--------| | **Optimal cost-performance** | 4720H | Best balance | | **Maximum toughness** | 4320H or 9310H | Higher nickel content | | **Cost optimization** | 8620H | Lower alloy cost | | **Aerospace certification** | 9310H | Premium performance | | **High volume automotive** | 4720H or 8620H | Consistency and cost | #### **H-Grade vs Standard Grade Justification:** | Decision Factor | Choose Standard 4720 When... | Choose 4720H When... | |-----------------|-----------------------------|----------------------| | **Volume** | Low volume, one-off parts | Medium to high volume | | **Criticality** | Non-critical components | Safety or performance critical | | **Heat Treatment** | Single heat treatment batch | Multiple batches over time | | **Assembly** | Manual adjustment possible | Automated assembly | | **Cost Focus** | Material cost primary | Total cost optimization | | **Quality System** | Basic quality requirements | Advanced quality systems (ISO/TS) | --- ### **12. TECHNICAL SPECIFICATION & PROCUREMENT** #### **Sample Procurement Specification:** ``` MATERIAL: AISI 4720H Alloy Steel Bars SPECIFICATION: ASTM A304, SAE J1268 Band 3 CONDITION: Annealed, 149-197 HB CHEMISTRY: Per SAE J404 with P≤0.020%, S≤0.020%, Al: 0.020-0.050% HARDENABILITY: Jominy curve to be supplied showing Band 3 compliance DIMENSIONS: [Specify sizes and tolerances per ASTM A29] TESTING REQUIREMENTS: - Jominy test on each heat - Chemical analysis (full spectrum) - Grain size: ASTM 6-8 minimum - Inclusion rating: ASTM E45 Method D, worst field ≤2.0 - Hardness verification (3 points minimum) CERTIFICATION: EN 10204 3.2 certificate required TRACEABILITY: Full heat number traceability maintained PACKAGING: Protected against corrosion, clearly marked ``` #### **Supplier Qualification Requirements:** - **Quality Certification:** ISO 9001, IATF 16949, or AS9100 - **Testing Capability:** In-house Jominy testing equipment - **Process Control:** SPC for chemistry and hardenability - **Experience:** Proven track record with H-grade materials - **Technical Support:** Engineering support available - **Traceability System:** Complete material history tracking #### **Quality Documentation Required:** - Material Test Certificate 3.2 (EN 10204) - Actual Jominy hardenability curve - Chemical analysis report (including residuals) - Heat treatment record (if supplied heat treated) - Dimensional inspection report - Optional: Microcleanliness report, macroetch photos --- ### **13. GLOBAL SUPPLY CHAIN CONSIDERATIONS** #### **Production Sources:** - **North America:** Major integrated mills and specialty producers - **Europe:** Widely available as 1.6523H - **Asia:** Produced in Japan, Korea, and increasingly in China - **Quality Variations:** Ensure supplier has proper H-grade controls #### **Lead Time Considerations:** - **Stock Material:** 1-3 weeks for common sizes/conditions - **Mill Production:** 8-12 weeks including testing - **Testing Time:** Additional 1-2 weeks for full certification - **Import Considerations:** Additional 2-4 weeks for certification validation #### **Cost Structure Analysis:** | Cost Component | Percentage of Total | Notes | |----------------|---------------------|-------| | **Base Material Premium** | 15-25% | Over standard 4720 | | **Testing & Certification** | 5-10% | Jominy test adds cost | | **Quality Assurance** | 3-5% | Additional controls | | **Total Premium** | 25-40% | Over standard grade | | **Justification** | Reduced processing costs and improved yield | Often 2-3× return on premium | #### **Inventory Management Strategy:** - **Safety Stock:** Lower requirements due to consistency - **Lot Sizes:** Can be larger with confidence in consistency - **First-In-First-Out:** Important but less critical than with standard grades - **Supplier Reduction:** Possible to single source due to consistency --- ### **14. TECHNICAL SUPPORT & ENGINEERING SERVICES** #### **Available Technical Support:** 1. **Heat Treatment Consulting:** - Optimal carburizing parameters - Quenching media selection - Tempering recommendations - Distortion minimization strategies 2. **Application Engineering:** - Case depth optimization - Core property recommendations - Design for manufacturability - Failure analysis support 3. **Quality Assurance Support:** - Testing protocol development - Statistical process control setup - Certification requirements guidance - Supplier quality management #### **Predictive Engineering Tools:** - **Case Depth Calculators:** Based on Jominy data - **Hardness Prediction Software:** For various sections and quenches - **Distortion Modeling:** Finite element analysis support - **Fatigue Life Prediction:** Based on consistent material data --- **TECHNICAL SUMMARY:** AISI 4720H represents the premium, hardenability-controlled version of nickel-chromium-molybdenum case-hardening steel. The H-grade designation ensures consistent heat treatment response through controlled chemistry and mandatory Jominy testing, providing predictable performance in critical applications. This material offers exceptional consistency for automotive, aerospace, industrial, and medical applications where reliability, traceability, and reduced variability are paramount. **PRIMARY VALUE PROPOSITION:** 1. **Unmatched Consistency:** Guaranteed hardenability within specified bands 2. **Predictable Performance:** Accurate case depth and hardness prediction 3. **Reduced Total Cost:** Lower processing costs offset material premium 4. **Improved Quality:** Higher first-pass yield and reduced inspection 5. **Enhanced Reliability:** Consistent component performance and life **APPLICATION GUIDELINES:** Specify AISI 4720H when: - Components require certification or qualification - Multiple production lots must be interchangeable - Heat treatment consistency affects assembly or performance - Statistical process control is implemented - Total cost optimization is more important than material cost minimization - Reliability and warranty considerations are significant --- **QUALITY COMMITMENT:** AISI 4720H is produced under stringent controls with mandatory Jominy testing to ensure hardenability compliance with SAE J1268. Each heat is fully traceable and certified, providing the reliability needed for critical applications in regulated industries. The material meets or exceeds all requirements of ASTM A304 for hardenability controlled steels. **DISCLAIMER:** The information provided represents typical properties based on standard specifications and guaranteed hardenability bands. Actual values for specific heats will fall within certified hardenability bands. For critical applications, review of actual Jominy curves and consultation with materials engineering professionals is essential. Proper heat treatment following recommended procedures is required to achieve specified properties. This material is intended for professional use in appropriate applications with proper engineering oversight. -:- For detailed product information, please contact sales. -: AISI 4720H Steel Specification Dimensions Size： Diameter 20-1000 mm Length <4083 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 4720H Steel Properties -:- For detailed product information, please contact sales. -:

Applications of AISI 4720H Steel Flange -:- For detailed product information, please contact sales. -: Chemical Identifiers AISI 4720H Steel Flange -:- For detailed product information, please contact sales. -:

Packing of AISI 4720H 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 554 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