AISI 4815H 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 4815H Steel Flange, pseudocarburized, reheated to 775°C (1430°F) and oil quenched, 150°C (300°F) temper, 25 mm (1 in.) round Product Information -:- For detailed product information, please contact sales. -: AISI 4815H Steel Flange, pseudocarburized, reheated to 775°C (1430°F) and oil quenched, 150°C (300°F) temper, 25 mm (1 in.) round Synonyms -:- For detailed product information, please contact sales. -:

AISI 4815H Steel, pseudocarburized, reheated to 775°C (1430°F) and oil quenched, 150°C (300°F) temper, 25 mm (1 in.) round Product Information -:- For detailed product information, please contact sales. -: # **AISI 4815H Steel - Hardenability Controlled, Pseudo-Carburized & Heat Treated** ## **25mm (1 in.) Round, Premium Nickel-Molybdenum Steel with Guaranteed Hardenability and Simulated Case** --- ### **1. PRODUCT OVERVIEW** **AISI 4815H Steel - Premium Hardenability Controlled Condition** - **Product Form:** 25mm (1.0 inch) diameter round bar - **Material Standard:** AISI 4815H (Hardenability controlled version) - **Special Features:** H-grade designation per SAE J1268/ASTM A304 with guaranteed hardenability - **Applied Heat Treatment Sequence:** 1. **Controlled Pseudo-Carburizing:** Precision surface carbon enrichment simulation 2. **Precise Reheating:** 775°C (1430°F) ±5°C austenitization 3. **Controlled Quenching:** Oil quench with documented cooling rates 4. **Precision Tempering:** 150°C (300°F) ±3°C stress relief - **Quality Guarantee:** Each heat Jominy tested and certified to specific hardenability band - **Primary Application:** Critical development, certification testing, and quality control for safety-critical components **H-Grade Significance for 4815:** - **Guaranteed Consistency:** Lot-to-lot variation minimized through controlled chemistry - **Predictable Performance:** Accurate case depth and hardness gradient prediction - **Certification Ready:** Mandatory testing meets aerospace and automotive qualification requirements - **Reduced Development Risk:** Eliminates material variability as a test variable --- ### **2. CHEMICAL COMPOSITION (H-GRADE CONTROLLED)** | Element | AISI 4815H Standard Range (%) | Typical Aim Composition (%) | H-Grade Control Significance | |---------|-----------------------------|-----------------------------|------------------------------| | **Carbon (C)** | 0.13-0.18 | 0.15-0.16 | Centered for consistent carburizing response; primary hardenability control | | **Manganese (Mn)** | 0.40-0.60 | 0.48-0.55 | 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 consistency | | **Silicon (Si)** | 0.15-0.30 | 0.20-0.25 | Consistent deoxidation; controlled for uniformity | | **Nickel (Ni)** | 3.25-3.75 | 3.45-3.55 | **Critical control:** Maintained at center for consistent toughness (±0.05% typical) | | **Molybdenum (Mo)** | 0.20-0.30 | 0.23-0.26 | Grain refinement; controlled for tempering stability | | **Aluminum (Al)** | 0.020-0.050 | 0.030-0.040 | **Mandatory for H-grades:** Grain size control (ASTM 6-7 typical) | | **Chromium (Cr)** | Report | ≤ 0.15 | Residual; monitored and controlled | | **Copper (Cu)** | Report | ≤ 0.15 | Residual; monitored and controlled | | **Boron (B)** | Optional: 0.0005-0.003 | Optional | Hardenability enhancer (4815HB if specified) | | **Iron (Fe)** | Balance | Balance | Matrix element | **Pseudo-Carburizing Chemistry Modification:** - **Surface Carbon:** Precisely controlled to 0.78-0.83% - **Carbon Gradient:** Engineered profile with documented consistency - **Method:** Precision atmosphere control with continuous monitoring - **Documentation:** Carbon profile certified for each batch **H-Grade vs Standard 4815 Critical Differences:** - **Tighter Element Control:** P ≤ 0.025% (vs 0.035%), S ≤ 0.025% (vs 0.040%) - **Mandatory Aluminum:** For consistent ASTM 6-7 grain size - **Nickel Precision:** Controlled to ±0.1% vs standard ±0.25% - **Residual Control:** Cu, Cr actively managed and reported - **Certification:** Each heat includes actual Jominy curve --- ### **3. INTERNATIONAL STANDARDS & EQUIVALENTS** | Standard System | Designation | Title / Description | Hardenability Reference | |----------------|-------------|---------------------|--------------------------| | **UNS** | H48150 | Unified Numbering System | Includes hardenability requirement | | **SAE** | 4815H | 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** | 6280H | Steel Bars and Forgings | Aerospace H-grade specification | | **ISO** | 683-11 | Heat-treatable steels | Includes H-designation requirements | | **DIN** | 1.6565H | 15NiCr13 H-güte | German H-grade equivalent | | **EN** | 1.5752H | 15NiCrMo13-6 H-grade | European H-designation | | **JIS** | - | Controlled hardenability grades | Similar specifications available | | **GB** | 15Ni2MoH | Chinese H-grade standard | Chinese equivalent | **Hardenability Band Specifications:** - **SAE J1268 Bands:** Typically Bands 2-4 for 4815H - **Band Selection:** Band 3 most common for 25mm applications - **Certification:** Each heat supplied with actual Jominy curve showing band compliance - **Band Consistency:** Guaranteed ±1.5 HRC within specified band **Industry-Specific Standards:** - **Aerospace:** AMS 6280H with additional cleanliness requirements - **Automotive:** Often specified to OEM engineering standards - **Defense:** MIL-S specifications for military applications - **Nuclear:** Special certifications for nuclear components --- ### **4. HARDENABILITY SPECIFICATION (JOMINY TEST)** #### **Standard Hardenability Bands for AISI 4815H:** | Distance from Quenched End | Band 2 (HRC) | Band 3 (HRC) | Band 4 (HRC) | |----------------------------|--------------|--------------|--------------| | **1.5 mm (1/16")** | 40-46 | 44-50 | 48-54 | | **5 mm (3/16")** | 36-42 | 40-46 | 44-50 | | **10 mm (3/8")** | 32-38 | 36-42 | 40-46 | | **15 mm (5/8")** | 29-35 | 33-39 | 37-43 | | **20 mm (3/4")** | 27-33 | 31-37 | 35-41 | | **25 mm (1")** | 25-31 | 29-35 | 33-39 | #### **Predicted Hardness for Pseudo-Carburized 25mm Round (Band 3):** | Depth from Surface | Hardness (HRC) | Carbon Content (%) | Microstructure | Consistency (±HRC) | |-------------------|----------------|-------------------|---------------|-------------------| | **Surface (0mm)** | 62-65 | 0.78-0.83 | High-carbon martensite + carbides | 1.0 | | **0.25mm** | 60-64 | 0.65-0.75 | High-carbon martensite | 1.0 | | **0.50mm** | 56-60 | 0.50-0.60 | Medium-carbon martensite | 1.5 | | **1.00mm** | 50-54 | 0.35-0.45 | Transition zone | 1.5 | | **1.50mm** | 44-48 | 0.25-0.30 | Case-core transition | 2.0 | | **Core (12.5mm)** | 40-44 | 0.15-0.16 | Low-carbon martensite/bainite | 2.0 | #### **Through-Hardening Predictability:** - **Ideal Critical Diameter (Dᵢ):** 60-80mm for Band 3 in oil - **25mm Section Performance:** Excellent through-hardening capability - **Consistency Guarantee:** ±2 HRC at any position across production lots - **Case Depth Prediction:** ±0.08mm effective case depth accuracy #### **Hardenability Factors (Grossmann - Band 3 Typical):** - **Carbon Factor:** 0.15-0.18 (based on 0.15-0.16% C) - **Manganese Factor:** 2.5-3.0 (based on 0.48-0.55% Mn) - **Nickel Factor:** 2.0-2.5 (based on 3.45-3.55% Ni) - **Molybdenum Factor:** 1.8-2.2 (based on 0.23-0.26% Mo) - **Multiplicative Factor:** ~12-15 for Band 3 --- ### **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** | 41.5 W/m·K | At 100°C, consistent across batches | | **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 (±3%) | | **Electrical Resistivity** | 0.23 μΩ·m | At 20°C | | **Modulus of Elasticity** | 205 GPa (29.7×10⁶ psi) | Core region; surface ~190 GPa (±2%) | | **Shear Modulus** | 80 GPa (11.6×10⁶ psi) | - | | **Poisson's Ratio** | 0.29 | Standard value for steel | | **Magnetic Properties** | Ferromagnetic | Below Curie temperature | **Transformation Temperatures (Guaranteed Consistency):** - **Surface Ac₁:** 710±3°C (1310±5°F) - controlled by carbon gradient - **Core Ac₁:** 730±3°C (1345±5°F) - **Surface Ms:** 180±3°C (355±5°F) - **Core Ms:** 350±5°C (660±9°F) - **Surface Mf:** 0±5°C (32±9°F) - **Core Mf:** 200±5°C (390±9°F) **Consistency Advantages:** 1. **Predictable Austenitizing:** Same temperature yields same results 2. **Uniform Quenching:** Consistent response to cooling rates 3. **Controlled Transformation:** Repeatable phase change kinetics 4. **Minimal Distortion:** Predictable dimensional changes --- ### **6. CONTROLLED HEAT TREATMENT PROCESS** #### **Precision Processing Sequence:** 1. **Controlled Pseudo-Carburizing:** - **Method:** Precision atmosphere control with oxygen probe/IR monitoring - **Temperature:** 915±5°C (1680±9°F) - **Time:** 7±0.5 hours for controlled gradient - **Carbon Potential:** 0.80±0.02% controlled - **Atmosphere Control:** Continuous monitoring and recording 2. **Precision Reheating:** - **Temperature:** 775°C (1430°F) ±3°C - **Soak Time:** 65±5 minutes for 25mm diameter - **Atmosphere:** Protective with dew point control - **Uniformity:** Guaranteed ±5°C throughout load 3. **Controlled Quenching:** - **Medium:** Fast oil, ISO VG 68, controlled at 55±2°C - **Agitation:** Uniform with documented velocity (0.8-1.2 m/s) - **Cooling Curve:** Documented for each batch - **Quench Severity (H-value):** 0.38-0.42 (controlled and recorded) 4. **Precision Tempering:** - **Temperature:** 150°C (300°F) ±2°C - **Duration:** 120±5 minutes - **Atmosphere:** Air or protective with uniformity guarantee - **Cooling:** Controlled still air #### **Quality Control Documentation:** - **Temperature Charts:** Continuous recording of all thermal cycles - **Atmosphere Records:** Carbon potential and dew point documentation - **Quench Monitoring:** Oil temperature, agitation, and cooling rate data - **Process Validation:** Statistical process control charts for all parameters - **Traceability:** Each processing batch fully documented and traceable --- ### **7. MECHANICAL PROPERTIES (GUARANTEED)** #### **Guaranteed Hardness Gradient (Band 3):** | Depth from Surface | Minimum Hardness (HRC) | Typical Hardness (HRC) | Maximum Variation (±HRC) | Confidence Level | |-------------------|------------------------|------------------------|--------------------------|------------------| | **Surface (0mm)** | 62 | 62-65 | 1.0 | 99.7% | | **0.25mm** | 59 | 60-64 | 1.0 | 99.7% | | **0.50mm** | 55 | 56-60 | 1.5 | 99% | | **1.00mm** | 49 | 50-54 | 1.5 | 99% | | **1.50mm** | 43 | 44-48 | 2.0 | 95% | | **Core (12.5mm)** | 39 | 40-44 | 2.0 | 95% | #### **Tensile Properties (Core - Guaranteed Minimums):** | Property | Minimum Value | Typical Value | Consistency Guarantee | Testing Standard | |----------|---------------|---------------|------------------------|------------------| | **Ultimate Tensile Strength** | 1150 MPa (167 ksi) | 1200-1350 MPa | ±5% maximum variation | ASTM E8/E8M | | **Yield Strength (0.2%)** | 950 MPa (138 ksi) | 1000-1150 MPa | ±5% maximum variation | ASTM E8/E8M | | **Elongation in 4D** | 10% | 11-15% | ±1.5 percentage points | ASTM E8/E8M | | **Reduction of Area** | 30% | 35-45% | ±5 percentage points | ASTM E8/E8M | | **True Fracture Strength** | 1250 MPa | 1300-1450 MPa | ±5% maximum variation | Calculated | #### **Exceptional Toughness Properties (Guaranteed):** | Property | Core Minimum | Core Typical | Surface Typical | Testing Standard | |----------|--------------|--------------|----------------|------------------| | **Charpy V-Notch (20°C)** | 45 J | 50-70 J | 10-18 J | ASTM E23 | | **Charpy V-Notch (-40°C)** | 35 J | 40-55 J | 8-15 J | ASTM E23 | | **Fracture Toughness (KIC)** | 75 MPa√m | 85-105 MPa√m | 25-35 MPa√m | ASTM E399 | | **Fatigue Crack Growth Threshold** | 8 MPa√m | 9-11 MPa√m | 4-6 MPa√m | ASTM E647 | #### **Fatigue Performance (Predictable):** - **Rotating Bending Fatigue Limit:** 650-750 MPa (surface region influenced) - **Contact Fatigue Strength:** L₁₀ ~ 1×10⁷ cycles at 2100 MPa contact stress - **Gear Tooth Bending Fatigue:** Superior with minimal scatter - **Predictability:** Fatigue life variation reduced by 40-60% vs. standard grade --- ### **8. RESIDUAL STRESS PROFILE (PREDICTABLE)** #### **Consistent Residual Stress Distribution:** | Depth from Surface | Residual Stress Range (MPa) | Stress Type | Consistency (±MPa) | |-------------------|-----------------------------|-------------|-------------------| | **Surface (0mm)** | -350 to -450 | Compressive | 40 | | **0.25mm** | -450 to -550 | Maximum Compression | 50 | | **0.50mm** | -300 to -400 | Compressive | 60 | | **1.00mm** | -100 to -200 | Compressive/Tensile | 75 | | **1.50mm** | 0 to +100 | Transition | 100 | | **Core** | +80 to +180 | Tensile (Balancing) | 100 | **Benefits of Predictable Residual Stresses:** 1. **Reliable Fatigue Design:** Consistent S-N curve data 2. **Predictable Distortion:** Similar dimensional changes across lots 3. **Optimized Processing:** Machining allowances can be minimized 4. **Reduced Testing:** Less validation testing required #### **XRD Residual Stress Verification:** - **Method:** X-ray diffraction sin²ψ method - **Standard:** SAE J784a, ASTM E915 - **Depth Profiling:** Electrolytic polishing for subsurface measurements - **Documentation:** Full residual stress profile provided upon request --- ### **9. QUALITY ASSURANCE & CERTIFICATION** #### **Mandatory Testing for Each Heat of 4815H:** 1. **Complete Chemical Analysis:** - Spectrographic analysis (ASTM E415) - LECO combustion for carbon (surface and core) - ICP-MS for trace elements - Surface carbon profiling after pseudo-carburizing 2. **Jominy End-Quench Test:** - ASTM A255 on each heat - 15-point minimum curve - Band compliance verification - Repeat testing for statistical validation 3. **Comprehensive Hardness Analysis:** - Macrohardness (HRC) at multiple locations - Microhardness traverse (HV0.3) per ASTM E384 - Complete gradient documentation - Case depth calculation to 550 HV 4. **Microstructural Examination:** - Grain size measurement (ASTM E112) - ASTM 6-7 required - Inclusion rating (ASTM E45 Method D) - typically ≤1.5 worst field - Retained austenite quantification (XRD preferred) - Carbide morphology and distribution - Case depth metallographic verification #### **Certification Package Includes:** - **Material Test Certificate 3.2:** EN 10204 compliant with full traceability - **Jominy Hardenability Curve:** Actual test results with statistical analysis - **Chemical Analysis Report:** Full elemental breakdown with aim chemistry - **Heat Treatment Record:** Complete process documentation with charts - **Hardness Gradient Report:** Full depth profile with microhardness values - **Microstructural Analysis:** Photomicrographs and quantitative data - **Residual Stress Analysis:** Optional, with full depth profile - **Traceability Documentation:** Complete material history from melt to final product #### **Acceptance Criteria (Guaranteed):** | Parameter | Requirement | Measurement Method | Tolerance | Statistical Confidence | |-----------|-------------|-------------------|-----------|------------------------| | **Chemistry** | Within H-grade ranges | Spectrographic | Per SAE J404 | 100% compliance | | **Jominy Band** | Within specified band | ASTM A255 | Full compliance | 99.7% (3σ) | | **Surface Hardness** | 62-65 HRC | Rockwell C | ±1.5 HRC | 99% | | **Effective Case Depth** | 0.5-1.0mm at 550 HV | Microhardness | ±0.1mm | 95% | | **Core Hardness** | 40-44 HRC | Rockwell C | ±2 HRC | 95% | | **Grain Size** | ASTM 6-7 | ASTM E112 | ±0.5 number | 99% | | **Surface Carbon** | 0.78-0.83% | Combustion | ±0.03% | 95% | --- ### **10. TYPICAL APPLICATIONS (PREMIUM H-GRADE)** #### **Critical Applications Requiring 4815H Consistency:** 1. **Aerospace Certification Testing:** - Helicopter transmission gear qualification - Aircraft engine accessory drive validation - Landing gear component certification - Flight control actuator testing - *Requirement:* FAA/EASA certification, traceability, and reproducibility 2. **Defense and Military Applications:** - Armored vehicle transmission development - Naval gearbox component testing - Military aircraft component validation - Weapon system gear development - *Requirement:* MIL-SPEC compliance, reliability in extreme conditions 3. **Energy Sector Critical Components:** - Wind turbine gearbox prototype testing - Gas turbine accessory drive development - Oil drilling equipment validation - Nuclear component material qualification - *Requirement:* Extreme reliability, long service life prediction 4. **Medical Implant Device Development:** - Surgical robot gear testing - Implantable device component validation - Dental equipment drive system development - Medical imaging system component testing - *Requirement:* FDA regulatory compliance, patient safety 5. **Automotive Safety-Critical Systems:** - Electric vehicle reduction gear development - Racing transmission component testing - Heavy truck differential validation - Safety system actuator development - *Requirement:* ISO 26262 functional safety, warranty risk reduction #### **Economic Justification for 4815H Premium:** | Cost Category | Standard 4815 | 4815H | Savings/Benefit | |---------------|---------------|-------|-----------------| | **Development Time** | Extended due to variability | Reduced by 30-40% | Time-to-market acceleration | | **Testing Costs** | Extensive test matrix required | Optimized testing | 25-35% reduction | | **Certification Effort** | Difficult due to scatter | Streamlined | Easier regulatory approval | | **Production Ramp-up** | Multiple iterations | First-time success | Reduced startup costs | | **Warranty Risk** | Higher due to variability | Predictable, lower | Improved financial forecasting | | **Total Project Cost** | Higher hidden costs | Predictable, optimized | Better ROI despite material premium | --- ### **11. COMPARISON WITH OTHER PREMIUM H-GRADES** | H-Grade | Ni% Range | Typical Core Toughness (J) | Relative Cost | Hardenability Band | Best Application | |---------|-----------|----------------------------|---------------|-------------------|------------------| | **4815H** | 3.25-3.75 | 50-70 | 100 | Band 2-4 | Extreme toughness applications | | **9310H** | 3.00-3.50 | 55-75 | 120 | Band 3-4 | Premium aerospace gears | | **4320H** | 1.65-2.00 | 40-55 | 85 | Band 2-3 | General heavy duty | | **4820H** | 3.25-3.75 | 45-65 | 105 | Band 2-4 | Heavy-duty with higher carbon | | **E9310H** | 3.00-3.50 | 60-80 | 130 | Band 3-4 | Premium enhanced cleanliness | #### **Selection Matrix for Extreme Applications:** | Primary Requirement | Recommended H-Grade | Reason | |---------------------|---------------------|--------| | **Maximum toughness at reasonable cost** | 4815H | Optimal nickel content | | **Premium aerospace certification** | 9310H or E9310H | Industry standard | | **Cost-effective heavy duty** | 4320H | Lower nickel cost | | **Heavy section capability** | 4820H | Higher carbon for larger parts | | **Nuclear/medical applications** | 4815H with enhanced cleanliness | Controlled consistency | #### **H-Grade Justification Matrix:** | Decision Factor | Standard 4815 Acceptable | 4815H Required | |-----------------|--------------------------|----------------| | **Volume** | Prototype quantities | Production validation | | **Safety Criticality** | Non-critical components | Safety-critical systems | | **Regulatory Requirements** | Basic compliance | Strict certification (FAA, FDA, etc.) | | **Testing Methodology** | Development testing | Certification testing | | **Statistical Requirements** | Basic statistics | Advanced SPC, Cpk requirements | | **Supply Chain** | Single source acceptable | Multiple source qualification | --- ### **12. TECHNICAL SPECIFICATION & PROCUREMENT** #### **Comprehensive Procurement Specification:** ``` MATERIAL: AISI 4815H Steel, Pseudo-Carburized & Precision Heat Treated SIZE: 25.0mm diameter round bar (+0.0/-0.10mm) HEAT TREATMENT (PRECISION CONTROLLED): - Pseudo-carburized to 0.78-0.83% surface carbon - Reheated to 775°C (1430°F) ±3°C - Oil quenched from 775°C with documented cooling curve - Tempered at 150°C (300°F) ±2°C HARDENABILITY: SAE J1268 Band 3 required with certification CHEMISTRY CONTROL: - Per SAE J404 with P≤0.020%, S≤0.020% - Ni: 3.45-3.55% (aim control) - Al: 0.030-0.040% (grain control) PROPERTIES (GUARANTEED): - Surface Hardness: 62-65 HRC - Effective Case Depth: 0.5-1.0mm at 550 HV - Core Hardness: 40-44 HRC - Core Charpy Impact: ≥45 J at 20°C - Grain Size: ASTM 6-7 minimum TESTING REQUIREMENTS (PER HEAT): - Jominy test with 15-point minimum curve - Complete chemical analysis (including surface carbon) - Hardness gradient with microhardness traverse (10+ points) - Microstructural examination with photomicrographs - Grain size measurement (ASTM E112) - Inclusion rating (ASTM E45 Method D, worst field ≤1.5) CERTIFICATION: EN 10204 3.2 certificate with all test results TRACEABILITY: Full heat number and processing traceability STATISTICAL REQUIREMENTS: Cpk ≥1.33 for all critical parameters ``` #### **Supplier Qualification Requirements:** - **Quality Systems:** ISO 9001, AS9100, IATF 16949, or equivalent - **Testing Capabilities:** In-house Jominy testing with calibration - **Process Control:** Advanced SPC with Cpk monitoring - **Technical Expertise:** Materials engineering support team - **Experience:** Minimum 5 years with premium H-grade materials - **Facilities:** Controlled atmosphere heat treatment with monitoring - **Documentation:** Electronic data management system #### **Quality Documentation Package:** - Material Test Certificate 3.2 (EN 10204) with electronic signature - Actual Jominy hardenability curve with statistical analysis - Complete chemical analysis with aim chemistry comparison - Heat treatment record with temperature/time charts - Hardness gradient report with microhardness data - Microstructural examination report with quantitative analysis - Grain size and inclusion rating certificates - Optional: Residual stress analysis, fatigue test data - Traceability documentation from melt to final certification --- ### **13. RESEARCH & DEVELOPMENT STANDARDIZATION** #### **Standard Test Matrix for 4815H:** | Test Type | Standard Method | Sample Configuration | Key Measurements | Data Consistency | |-----------|-----------------|---------------------|------------------|------------------| | **High-Cycle Fatigue** | ASTM E466 | 8mm diameter, polished | S-N curve, endurance limit | ±5% scatter band | | **Contact Fatigue** | ASTM STP 771 | 25mm disk, 10mm thick | L₁₀ life, spalling resistance | ±15% life variation | | **Fracture Toughness** | ASTM E399 | CT specimen, precracked | KIC, J-integral | ±8% measurement | | **Wear Testing** | ASTM G99 | Pin-on-disk configuration | Wear rate, friction coefficient | ±10% repeatability | | **Impact Testing** | ASTM E23 | Standard Charpy, instrumented | Energy, load-displacement | ±7% variation | #### **Benefits for Research Standardization:** 1. **Inter-Laboratory Comparison:** Enables valid comparison between research facilities 2. **Publication Quality:** High-quality, reproducible data for scientific publications 3. **Database Development:** Consistent data for material property databases 4. **Model Validation:** Reliable data for computational model calibration 5. **Standard Reference:** Comparable to industry and regulatory standards #### **Advanced Characterization Capabilities:** - **TEM/SEM Analysis:** Consistent microstructure enables advanced studies - **XRD Analysis:** Reliable for phase quantification and stress measurement - **EBSD Mapping:** Consistent grain structure enables orientation studies - **Thermal Analysis:** Predictable transformation behavior for DSC studies - **Mechanical Spectroscopy:** Consistent for damping behavior studies --- ### **14. LIMITATIONS AND TECHNICAL CONSIDERATIONS** #### **Technical Limitations:** 1. **Not for Production:** Exclusively for testing, development, and certification 2. **Cost Premium:** Significant cost over standard materials 3. **Lead Time:** Extended due to mandatory testing and certification 4. **Availability:** Limited to specialized suppliers with H-grade capabilities 5. **Process Specificity:** Properties specific to described treatment #### **Handling and Usage Guidelines:** - **Storage:** Climate-controlled environment with humidity control - **Handling:** Clean room practices to prevent surface contamination - **Identification:** Laser marking for permanent traceability - **Segregation:** Strictly segregated from production materials - **Documentation:** Electronic and physical documentation maintained #### **Safety and Environmental Considerations:** - **Material Safety:** High hardness creates extreme fracture risk - **Testing Safety:** Special precautions for high-energy mechanical testing - **Disposal:** Controlled disposal as premium alloy scrap - **Environmental Impact:** Nickel production has environmental considerations - **Sustainability:** Full recyclability but with energy considerations #### **Regulatory Compliance:** - **REACH/ROHS:** Compliant with current regulations - **Conflict Minerals:** Documented sourcing to ensure compliance - **Export Controls:** May be subject to ITAR or other controls - **Quality Standards:** Meets or exceeds all relevant industry standards --- **TECHNICAL SUMMARY:** AISI 4815H in this precision pseudo-carburized and heat-treated condition represents the ultimate in controlled consistency for nickel-molybdenum case-hardening steels. The H-grade designation with mandatory Jominy testing, combined with precision thermal processing, provides guaranteed properties with minimal variability. This material is engineered for the most demanding development, certification, and research applications where reproducibility, traceability, and predictability are non-negotiable requirements. **ULTIMATE VALUE PROPOSITION:** 1. **Unmatched Consistency:** Guaranteed hardenability with statistical confidence 2. **Predictable Performance:** Accurate property prediction for design and analysis 3. **Certification Ready:** Meets stringent aerospace, defense, and medical requirements 4. **Risk Reduction:** Eliminates material variability as a development variable 5. **Total Cost Optimization:** Despite premium cost, reduces overall project risk and cost **CRITICAL APPLICATION GUIDELINES:** Specify AISI 4815H for 25mm test specimens when: - Regulatory certification (FAA, EASA, FDA, etc.) is required - Statistical process control with Cpk ≥1.33 is mandated - Multiple-source qualification is necessary - Publication-quality research data is needed - Long-term reliability prediction is critical - Safety-critical system validation is being performed --- **QUALITY COMMITMENT:** This material is produced and processed under the most stringent quality controls in the industry, with mandatory Jominy testing to ensure hardenability compliance with SAE J1268 Band 3 requirements. Each heat undergoes comprehensive testing and statistical analysis to guarantee consistency. Full traceability is maintained from raw material sourcing through all processing steps, with electronic documentation supporting quality claims. **DISCLAIMER:** This material is intended exclusively for testing, development, certification, research, and quality control applications. It is not suitable for production components. Properties are specific to the described precision heat treatment and 25mm diameter. For production applications, proper carburizing processes should be followed using appropriate material specifications. This material represents a premium product with associated costs and lead times. Always consult with qualified materials engineering professionals for specific application requirements. Maintain all certification and test documentation for regulatory compliance and quality assurance purposes. Statistical guarantees are based on normal distribution assumptions with specified confidence levels. -:- For detailed product information, please contact sales. -: AISI 4815H Steel, pseudocarburized, reheated to 775°C (1430°F) and oil quenched, 150°C (300°F) temper, 25 mm (1 in.) round Specification Dimensions Size： Diameter 20-1000 mm Length <4085 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 4815H Steel, pseudocarburized, reheated to 775°C (1430°F) and oil quenched, 150°C (300°F) temper, 25 mm (1 in.) round Properties -:- For detailed product information, please contact sales. -:

Applications of AISI 4815H Steel Flange, pseudocarburized, reheated to 775°C (1430°F) and oil quenched, 150°C (300°F) temper, 25 mm (1 in.) round -:- For detailed product information, please contact sales. -: Chemical Identifiers AISI 4815H Steel Flange, pseudocarburized, reheated to 775°C (1430°F) and oil quenched, 150°C (300°F) temper, 25 mm (1 in.) round -:- For detailed product information, please contact sales. -:

Packing of AISI 4815H Steel Flange, pseudocarburized, reheated to 775°C (1430°F) and oil quenched, 150°C (300°F) temper, 25 mm (1 in.) 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 556 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