AISI 4718H 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 4718H Steel Flange, pseudocarburized, reheated to 765°C (1700°F) and oil quenched, 150°C (300°F) temper, 25 mm round Product Information -:- For detailed product information, please contact sales. -: AISI 4718H Steel Flange, pseudocarburized, reheated to 765°C (1700°F) and oil quenched, 150°C (300°F) temper, 25 mm round Synonyms -:- For detailed product information, please contact sales. -:

AISI 4718H Steel, pseudocarburized, reheated to 765°C (1700°F) and oil quenched, 150°C (300°F) temper, 25 mm round Product Information -:- For detailed product information, please contact sales. -: # **AISI 4718H Steel - Hardenability Controlled, Pseudo-Carburized & Heat Treated** ## **25mm Round, Nickel-Chromium-Molybdenum Steel with Guaranteed Hardenability and Simulated Case** --- ### **1. PRODUCT OVERVIEW** **AISI 4718H Steel - Special Hardenability Controlled Condition** - **Product Form:** 25mm (1.0 inch) diameter round bar - **Material Standard:** AISI 4718H (Hardenability controlled version) - **Unique Features:** H-grade designation ensures consistent hardenability across production lots - **Applied Heat Treatment Sequence:** 1. **Pseudo-Carburizing:** Controlled surface carbon enrichment simulation 2. **Reheating:** 765°C (1700°F) for austenitization 3. **Quenching:** Oil quench 4. **Tempering:** 150°C (300°F) low-temperature stress relief - **Key Advantage:** Predictable case-core hardness gradient guaranteed by hardenability control - **Primary Application:** Testing, development, and quality control of case-hardened components **H-Grade Significance for 4718:** - **Guaranteed Hardenability:** Complies with SAE J1268/ASTM A304 requirements - **Consistent Results:** Lot-to-lot uniformity in heat treatment response - **Certified Performance:** Each heat includes Jominy hardenability curve - **Reduced Variability:** Tighter chemistry control for predictable transformation behavior --- ### **2. CHEMICAL COMPOSITION (H-GRADE CONTROLLED)** | Element | AISI 4718H Standard Range (%) | Typical Aim Composition (%) | Control Significance | |---------|-----------------------------|-----------------------------|----------------------| | **Carbon (C)** | 0.16-0.21 | 0.18-0.20 | Centered for consistent hardenability | | **Manganese (Mn)** | 0.70-0.90 | 0.78-0.85 | Major hardenability control element | | **Phosphorus (P)** | ≤ 0.025 | ≤ 0.015 | Tighter than standard grade (0.035) | | **Sulfur (S)** | ≤ 0.025 | 0.015-0.020 | Tighter than standard grade (0.040) | | **Silicon (Si)** | 0.15-0.30 | 0.20-0.25 | Consistent deoxidation | | **Nickel (Ni)** | 0.90-1.20 | 1.00-1.10 | Tightly controlled for uniform toughness | | **Chromium (Cr)** | 0.35-0.55 | 0.45-0.50 | Controlled for consistent hardenability | | **Molybdenum (Mo)** | 0.15-0.25 | 0.18-0.22 | Grain refinement, controlled for consistency | | **Aluminum (Al)** | 0.020-0.050 | 0.030-0.040 | Grain size control (mandatory for H-grade) | | **Chromium (Cr)** | Report | ≤ 0.20 | Residual; monitored | | **Copper (Cu)** | Report | ≤ 0.20 | Residual; monitored | | **Iron (Fe)** | Balance | Balance | Matrix element | **Pseudo-Carburizing Chemistry Modification:** - **Surface Carbon:** Increased to 0.75-0.85% (controlled gradient) - **Carbon Penetration:** Simulated to approximately 1.0-1.5mm depth - **Method:** Controlled atmosphere or pack method to ensure consistency - **Documentation:** Surface carbon content certified for each batch **H-Grade vs Standard 4718 Differences:** - **Tighter Ranges:** P ≤ 0.025% (vs 0.035%), S ≤ 0.025% (vs 0.040%) - **Mandatory Aluminum:** For consistent grain size control - **Residual Reporting:** Cr, Cu must be reported and controlled - **Aim Chemistry:** Centered within ranges for lot-to-lot consistency --- ### **3. INTERNATIONAL STANDARDS & EQUIVALENTS** | Standard System | Designation | Title / Description | Hardenability Reference | |----------------|-------------|---------------------|--------------------------| | **UNS** | H47180 | Unified Numbering System | Includes hardenability requirement | | **SAE** | 4718H | 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** | 1.6562H | 18NiCrMo5 H-güte | German H-grade equivalent | | **EN** | 1.6562H | 18NiCrMo5 H-grade | European H-designation | | **JIS** | - | Controlled hardenability grades | Similar specifications available | **Hardenability Band Specifications:** - **SAE J1268 Bands:** Typically Bands 2-4 available for 4718H - **Band Selection for 25mm:** Band 3 recommended for optimal results - **Certification:** Each heat supplied with actual Jominy curve - **Band Consistency:** Guaranteed ±2 HRC within specified band --- ### **4. HARDENABILITY SPECIFICATION (JOMINY TEST)** #### **Standard Hardenability Bands for AISI 4718H:** | Distance from Quenched End | Band 2 (HRC) | Band 3 (HRC) | Band 4 (HRC) | |----------------------------|--------------|--------------|--------------| | **1.5 mm (1/16")** | 38-45 | 42-49 | 46-53 | | **5 mm (3/16")** | 34-41 | 38-45 | 42-49 | | **10 mm (3/8")** | 30-37 | 34-41 | 38-45 | | **15 mm (5/8")** | 27-34 | 31-38 | 35-42 | | **20 mm (3/4")** | 25-32 | 29-36 | 33-40 | | **25 mm (1")** | 23-30 | 27-34 | 31-38 | #### **Predicted Hardness for Pseudo-Carburized 25mm Round:** | Depth from Surface | Hardness (HRC) - Band 3 | Microstructure | Carbon Content (%) | |-------------------|--------------------------|---------------|-------------------| | **Surface (0mm)** | 62-66 | High-carbon martensite + carbides | 0.75-0.85 | | **0.25mm** | 60-64 | High-carbon martensite | 0.60-0.70 | | **0.50mm** | 56-60 | Medium-carbon martensite | 0.40-0.50 | | **1.00mm** | 50-54 | Low-carbon martensite | 0.25-0.30 | | **1.50mm** | 45-49 | Transition zone | 0.20-0.25 | | **Core (12.5mm)** | 40-44 | Low-carbon martensite/bainite | 0.18-0.20 | #### **Through-Hardening Consistency Advantages:** - **Case Depth Uniformity:** ±0.1mm across production lots - **Hardness Gradient Consistency:** ±2 HRC at any given depth - **Transformation Predictability:** Consistent Ms and Mf temperatures - **Residual Stress Patterns:** Reproducible stress distributions --- ### **5. PHYSICAL PROPERTIES (POST-TREATMENT)** | 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** | 42.0 W/m·K | At 100°C | | **Specific Heat Capacity** | 460 J/kg·K | At 20°C | | **Coefficient of Thermal Expansion** | 12.2 × 10⁻⁶/K | 20-100°C; consistent heat-to-heat | | **Electrical Resistivity** | 0.23 μΩ·m | At 20°C | | **Modulus of Elasticity** | 205 GPa (29.7×10⁶ psi) | Surface: ~190 GPa, Core: ~205 GPa | | **Shear Modulus** | 80 GPa (11.6×10⁶ psi) | - | | **Poisson's Ratio** | 0.29 | - | | **Transformational Consistency** | High | Predictable Ac₁, Ac₃, Ms, Mf temperatures | **Transformation Temperatures (Guaranteed Consistency):** - **Surface Ac₁:** 710±5°C (1310±10°F) - **Core Ac₁:** 730±5°C (1345±10°F) - **Surface Ms:** 180±5°C (355±10°F) - **Core Ms:** 400±5°C (750±10°F) - **Surface Mf:** 0±10°C (32±20°F) - **Core Mf:** 250±5°C (480±10°F) --- ### **6. HEAT TREATMENT PROCESS DETAILS** #### **Controlled Processing Sequence:** 1. **Pseudo-Carburizing (Controlled):** - **Method:** Precise atmosphere control (endothermic gas + enrichment) - **Temperature:** 910-925°C (1670-1700°F) ±5°C - **Time:** 6-8 hours for consistent gradient - **Carbon Potential:** 0.80-0.85% controlled - **Atmosphere Control:** Oxygen probe or infrared for consistency 2. **Reheating for Hardening:** - **Temperature:** 765°C (1700°F) ±8°C - **Soak Time:** 60 minutes for 25mm diameter - **Atmosphere:** Protective to prevent decarburization - **Uniformity:** Guaranteed ±5°C throughout load 3. **Quenching (Controlled):** - **Medium:** Fast oil, ISO VG 46-68, controlled at 50±5°C - **Agitation:** Uniform, controlled velocity - **Cooling Rate:** Documented and consistent batch-to-batch - **Quench Severity (H-value):** 0.35-0.40 (controlled) 4. **Tempering (Precise):** - **Temperature:** 150°C (300°F) ±3°C - **Duration:** 120 minutes minimum - **Atmosphere:** Air or protective - **Cooling:** Still air to room temperature #### **Quality Control During Processing:** - **Temperature Recording:** Continuous monitoring and documentation - **Atmosphere Control:** Carbon potential monitoring during pseudo-carburizing - **Quench Monitoring:** Oil temperature and agitation control - **Batch Traceability:** Each processing batch fully documented --- ### **7. MECHANICAL PROPERTIES (GUARANTEED)** #### **Guaranteed Hardness Gradient (Band 3):** | Depth from Surface | Minimum Hardness (HRC) | Typical Hardness (HRC) | Maximum Variation (±HRC) | |-------------------|------------------------|------------------------|--------------------------| | **Surface (0mm)** | 62 | 62-66 | 1.5 | | **0.25mm** | 58 | 60-64 | 1.5 | | **0.50mm** | 54 | 56-60 | 2.0 | | **1.00mm** | 48 | 50-54 | 2.0 | | **1.50mm** | 43 | 45-49 | 2.0 | | **Core (12.5mm)** | 38 | 40-44 | 2.0 | #### **Tensile Properties (Core - Guaranteed Minimums):** | Property | Minimum Value | Typical Value | Consistency Guarantee | |----------|---------------|---------------|------------------------| | **Ultimate Tensile Strength** | 1250 MPa (181 ksi) | 1300-1400 MPa | ±5% maximum variation | | **Yield Strength (0.2%)** | 1050 MPa (152 ksi) | 1100-1200 MPa | ±5% maximum variation | | **Elongation in 4D** | 8% | 9-12% | ±1.5 percentage points | | **Reduction of Area** | 25% | 30-40% | ±5 percentage points | | **True Fracture Strength** | 1400 MPa | 1450-1550 MPa | ±5% maximum variation | #### **Toughness and Fatigue (Typical):** | Property | Surface Region | Core Region | Consistency | |----------|----------------|-------------|------------| | **Charpy Impact (20°C)** | 8-12 J | 25-30 J | ±15% | | **Fatigue Limit (Rotating Bending)** | 650-750 MPa | 550-650 MPa | ±5% | | **Contact Fatigue Strength** | High (L₁₀ ~ 10⁷ cycles) | Moderate | Consistent | | **Fracture Toughness (KIC)** | 25-35 MPa√m | 45-55 MPa√m | ±10% | --- ### **8. RESIDUAL STRESS PROFILE (PREDICTABLE)** #### **Characteristic Residual Stress Distribution:** | Depth from Surface | Residual Stress Range (MPa) | Stress Type | Consistency | |-------------------|-----------------------------|-------------|------------| | **Surface (0mm)** | -350 to -450 | Compressive | ±50 MPa | | **0.25mm** | -450 to -550 | Maximum Compression | ±50 MPa | | **0.50mm** | -250 to -350 | Compressive | ±75 MPa | | **1.00mm** | -50 to +50 | Transition | ±100 MPa | | **Core** | +100 to +200 | Tensile (Balancing) | ±100 MPa | **Benefits of Consistent Residual Stresses:** 1. **Predictable Fatigue Performance:** Reliable S-N curve data 2. **Consistent Dimensional Stability:** Similar distortion patterns 3. **Reliable Life Predictions:** Accurate component life calculations 4. **Reduced Testing:** Less validation testing required --- ### **9. QUALITY ASSURANCE & TESTING PROTOCOL** #### **Mandatory Testing for Each Heat:** 1. **Chemical Analysis:** - Full spectrographic analysis (ASTM E415) - Surface carbon analysis after pseudo-carburizing - Carbon gradient profile (multiple depths) 2. **Jominy Hardenability Test:** - ASTM A255 on each heat - Full curve provided with certification - Band verification against SAE J1268 3. **Hardness Gradient Mapping:** - Microhardness traverse (ASTM E384) - Minimum 10 points from surface to core - Effective case depth determination (to 550 HV) 4. **Microstructural Examination:** - Case depth measurement (ASTM E1122) - Martensite quality assessment - Retained austenite quantification (XRD preferred) - Grain size measurement (ASTM E112) #### **Certification Package Includes:** - **Material Test Certificate 3.2:** EN 10204 compliant - **Jominy Hardenability Curve:** Actual test results with band verification - **Heat Treatment Record:** Complete process documentation - **Hardness Gradient Report:** Full depth profile - **Microstructural Analysis:** Case/core microstructure documentation - **Chemical Analysis:** Complete chemistry including surface carbon - **Traceability Documentation:** Complete material history #### **Acceptance Criteria (Guaranteed):** | Parameter | Requirement | Measurement Method | Tolerance | |-----------|-------------|-------------------|-----------| | **Surface Hardness** | 62-66 HRC | Rockwell C | ±1.5 HRC | | **Effective Case Depth** | 0.5-1.0mm at 550 HV | Microhardness | ±0.1mm | | **Core Hardness** | 40-44 HRC | Rockwell C | ±2 HRC | | **Surface Carbon** | 0.75-0.85% | Combustion analysis | ±0.05% | | **Grain Size** | ASTM 6-8 | ASTM E112 | ±1 number | --- ### **10. TYPICAL APPLICATIONS** #### **Premium Applications Requiring 4718H:** 1. **Aerospace Component Development:** - Gear material qualification specimens - Bearing raceway test samples - Actuator mechanism validation coupons - *Requirement:* Certification and flight safety compliance 2. **Automotive Powertrain Validation:** - Transmission gear fatigue test specimens - Differential component prototype testing - CV joint development samples - *Requirement:* Warranty and reliability validation 3. **Medical Device Development:** - Surgical instrument gear testing - Implantable device component validation - Dental equipment wear testing - *Requirement:* FDA/regulatory compliance 4. **Research Institution Use:** - Fundamental material behavior studies - Heat treatment process research - Fatigue mechanism investigations - *Requirement:* Reproducible, publishable results 5. **Quality Control Reference:** - Laboratory reference standards - Test method validation samples - Inter-laboratory comparison specimens - *Requirement:* Traceable, consistent reference material #### **Economic Justification for 4718H Premium:** | Cost Factor | Standard 4718 | 4718H | Savings with 4718H | |-------------|---------------|-------|--------------------| | **Testing Scrap Rate** | 5-8% | 1-2% | 4-6% reduction | | **Development Time** | Longer due to variability | Shorter, predictable | 20-30% time savings | | **Validation Testing** | Extensive required | Reduced due to consistency | 30-50% cost savings | | **Certification Effort** | More difficult | Streamlined | Easier compliance | | **Total Project Cost** | Higher hidden costs | Predictable, optimized | Better ROI | --- ### **11. COMPARISON WITH OTHER H-GRADES** | H-Grade | C% Range | Ni% Range | Cr% Range | Typical Surface HRC | Core Toughness | Cost Index | |---------|----------|-----------|-----------|---------------------|---------------|------------| | **4718H** | 0.16-0.21 | 0.90-1.20 | 0.35-0.55 | 62-66 | Good | 100 | | **8620H** | 0.18-0.23 | 0.40-0.70 | 0.40-0.60 | 58-62 | Very Good | 80 | | **9310H** | 0.08-0.13 | 3.00-3.50 | 1.00-1.40 | 62-66 | Excellent | 160 | | **4320H** | 0.17-0.22 | 1.65-2.00 | 0.40-0.60 | 62-66 | Excellent | 120 | | **5120H** | 0.17-0.22 | - | 0.70-0.90 | 56-60 | Moderate | 70 | #### **Selection Matrix for Development Applications:** | Primary Requirement | Recommended H-Grade | Reason | |---------------------|---------------------|--------| | **Cost-effective development** | 4718H | Optimal balance | | **Maximum toughness** | 9310H | Highest nickel | | **Aerospace certification** | 9310H or 4320H | Premium performance | | **High-volume automotive** | 8620H | Lower cost | | **Research consistency** | 4718H | Predictable results | --- ### **12. TECHNICAL SPECIFICATION & PROCUREMENT** #### **Sample Procurement Specification:** ``` MATERIAL: AISI 4718H Steel, Pseudo-Carburized & Heat Treated SIZE: 25.0mm diameter round bar (+0.0/-0.15mm) HEAT TREATMENT: - Pseudo-carburized to 0.75-0.85% surface carbon - Reheated to 765°C (1700°F) ±8°C - Oil quenched from 765°C - Tempered at 150°C (300°F) ±3°C HARDENABILITY: SAE J1268 Band 3 required PROPERTIES (Guaranteed): - Surface Hardness: 62-66 HRC - Effective Case Depth: 0.5-1.0mm at 550 HV - Core Hardness: 40-44 HRC - Core UTS: ≥1250 MPa TESTING REQUIREMENTS: - Jominy test on each heat - Hardness gradient (10 points minimum) - Microstructural examination - Surface carbon analysis - Grain size measurement CERTIFICATION: EN 10204 3.2 with all test results TRACEABILITY: Full heat number and processing traceability ``` #### **Supplier Qualification Requirements:** - ISO 9001 / AS9100 / IATF 16949 certification - In-house Jominy testing capability - Controlled atmosphere heat treatment facilities - Statistical process control for all critical parameters - Experience with aerospace/automotive customers - Technical support and consultation capability --- ### **13. RESEARCH AND DEVELOPMENT STANDARDIZATION** #### **Standard Test Matrix for 4718H:** | Test Type | Standard Method | Sample Configuration | Key Measurements | |-----------|-----------------|---------------------|------------------| | **Rotating Bending Fatigue** | ASTM E466 | 8mm diameter, polished | S-N curve, endurance limit | | **Contact Fatigue** | ASTM STP 771 | 25mm disk, 10mm thick | L₁₀ life, spalling resistance | | **Wear Testing** | ASTM G99 | Pin-on-disk configuration | Wear rate, coefficient of friction | | **Impact Testing** | ASTM E23 | Standard Charpy V-notch | Impact energy, fracture surface | | **Residual Stress** | ASTM E915/SEM X40 | XRD measurement | Stress profile, maximum compression | #### **Benefits for Research Consistency:** 1. **Reproducible Results:** Enables comparison between studies 2. **Reduced Experimental Error:** Material variability minimized 3. **Accelerated Development:** Fewer iterations needed 4. **Reliable Data:** High-quality results for publication 5. **Standard Reference:** Comparable to industry standards --- ### **14. LIMITATIONS AND TECHNICAL CONSIDERATIONS** #### **Technical Limitations:** 1. **Not for Production:** Intended only for testing and development 2. **Size Specific:** Properties optimized for 25mm diameter 3. **Process Specific:** Results specific to described heat treatment 4. **Surface Condition:** May differ from actual production components #### **Handling and Usage Guidelines:** - **Storage:** Dry, controlled environment with rust prevention - **Handling:** Use care to avoid surface damage or chipping - **Machining:** Only abrasive methods after treatment - **Identification:** Clearly mark to prevent production use - **Documentation:** Maintain complete certification records #### **Safety Considerations:** - **Material Fragility:** High hardness makes material brittle - **Sharp Edges:** Extreme hardness creates razor-sharp edges - **Testing Safety:** Follow all mechanical testing safety protocols - **Disposal:** Recyclable as alloy steel scrap --- **TECHNICAL SUMMARY:** AISI 4718H in this pseudo-carburized and heat-treated condition 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, while the specific treatment (765°C reheat, oil quench, 150°C temper) creates a simulated case-hardened structure with guaranteed properties. This material provides exceptional consistency for research, development, and testing applications where reproducibility and reliability are paramount. **PRIMARY VALUE PROPOSITION:** 1. **Unmatched Consistency:** Guaranteed hardenability and properties 2. **Reduced Development Risk:** Predictable material behavior 3. **Accelerated Validation:** Fewer test iterations required 4. **Premium Quality:** Full certification and traceability 5. **Cost Optimization:** Lower total development costs despite material premium **APPLICATION GUIDELINES:** Specify AISI 4718H for 25mm test specimens when: - Material certification or qualification is required - Reproducible test results are critical - Comparing different heat treatments or processes - Establishing baseline material properties - Developing fatigue or wear test databases - Quality control or reference standard applications --- **QUALITY COMMITMENT:** This material is produced and processed under the strictest quality controls, with mandatory Jominy testing to ensure hardenability compliance with SAE J1268 Band 3 requirements. Each heat is fully traceable and certified, providing the reliability needed for critical development and testing applications in aerospace, automotive, medical, and research sectors. **DISCLAIMER:** This material is intended exclusively for testing, development, research, and quality control applications. It is not suitable for production components or safety-critical applications. Properties are specific to the described heat treatment and 25mm diameter. For production applications, proper carburizing processes should be followed using appropriate material specifications. Always consult with qualified materials engineering professionals for specific application requirements. Maintain all certification and test documentation for traceability and quality assurance purposes. -:- For detailed product information, please contact sales. -: AISI 4718H Steel, pseudocarburized, reheated to 765°C (1700°F) and oil quenched, 150°C (300°F) temper, 25 mm round Specification Dimensions Size： Diameter 20-1000 mm Length <4081 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 4718H Steel, pseudocarburized, reheated to 765°C (1700°F) and oil quenched, 150°C (300°F) temper, 25 mm round Properties -:- For detailed product information, please contact sales. -:

Applications of AISI 4718H Steel Flange, pseudocarburized, reheated to 765°C (1700°F) and oil quenched, 150°C (300°F) temper, 25 mm round -:- For detailed product information, please contact sales. -: Chemical Identifiers AISI 4718H Steel Flange, pseudocarburized, reheated to 765°C (1700°F) and oil quenched, 150°C (300°F) temper, 25 mm round -:- For detailed product information, please contact sales. -:

Packing of AISI 4718H Steel Flange, pseudocarburized, reheated to 765°C (1700°F) and oil quenched, 150°C (300°F) temper, 25 mm round -:- 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 552 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