AISI 4419H Steel, single quenched and tempered

AISI 4419H Steel, single quenched and tempered, 150°C (300°F) Product Information -:- For detailed product information, please contact sales. -: AISI 4419H Steel, single quenched and tempered, 150°C (300°F) Synonyms -:- For detailed product information, please contact sales. -:

AISI 4419H Steel, single quenched and tempered, 150°C (300°F) Product Information -:- For detailed product information, please contact sales. -: # **Technical Specification: AISI 4419H Steel, Single Quenched & Tempered at 150°C (300°F)** ## **1. PRODUCT OVERVIEW** AISI 4419H steel processed through **single quench and temper (SQ&T)** heat treatment at 150°C (300°F) represents a high-performance through-hardening alloy steel. This treatment involves direct austenitization followed by rapid quenching and a low-temperature tempering cycle, producing a **uniform tempered martensitic microstructure** throughout the cross-section. This condition provides an optimal balance of ultra-high strength, good toughness retention, and excellent wear resistance without case carburizing. ## **2. MATERIAL SPECIFICATIONS** ### **2.1 Designation & Standards** | **Parameter** | **Specification** | |---------------|-------------------| | **Material Designation** | AISI 4419H / SAE 4419H | | **International Standards** | ASTM A304, SAE J1268 (H-steel), ISO 683-11 | | **Heat Treatment Standard** | AMS 2759 (Pyrometry) / ASTM A255 (Hardenability) | | **Processing Condition** | Single Quenched & Tempered | | **Tempering Temperature** | 150°C ± 10°C (300°F ± 20°F) | ### **2.2 Chemical Composition (SAE J1268 Limits)** | **Element** | **Min (%)** | **Max (%)** | **Typical (%)** | **Function** | |-------------|-------------|-------------|----------------|-------------| | **Carbon (C)** | 0.17 | 0.23 | 0.20 | Primary hardenability and strength | | **Manganese (Mn)** | 0.45 | 0.65 | 0.55 | Hardenability enhancer | | **Silicon (Si)** | 0.15 | 0.35 | 0.25 | Deoxidizer, solid solution strengthening | | **Chromium (Cr)** | 0.35 | 0.55 | 0.45 | Hardenability and tempering resistance | | **Molybdenum (Mo)** | 0.08 | 0.15 | 0.12 | Grain refinement, hardenability | | **Boron (B)** | 0.0005 | 0.003 | 0.0015 | Powerful hardenability multiplier | | **Phosphorus (P)** | — | 0.035 | 0.015 | Residual element | | **Sulfur (S)** | — | 0.040 | 0.025 | Residual element (machinability) | ## **3. HEAT TREATMENT PROCESS** ### **3.1 Process Flow** ``` Austenitization → Rapid Quenching → Low-Temperature Tempering ``` **Critical Parameters:** - **Austenitization Temperature:** 850-870°C (1560-1600°F) under protective atmosphere - **Soak Time:** 30-60 minutes per inch of thickness - **Quenching Medium:** Fast oil or polymer quenchant (based on section size) - **Tempering:** 150°C (300°F) for 2-4 hours, air cooled - **Prior Austenite Grain Size:** ASTM 7-8 (fine grain) ### **3.2 Microstructural Characteristics** - **Primary Phase:** Tempered lath martensite with minimal retained austenite (<5%) - **Carbide Precipitation:** Fine ε-carbides within martensite laths - **Grain Boundary Characteristics:** Clean, carbide-free boundaries - **Hardenability Depth:** Full through-hardening up to 75 mm (3 in.) diameter ## **4. MECHANICAL PROPERTIES** ### **4.1 Tensile Properties (at 25°C / 77°F)** | **Property** | **Typical Value** | **Test Method** | |--------------|-------------------|-----------------| | **Hardness** | 44-48 HRC | ASTM E18 | | **Ultimate Tensile Strength** | 1450-1600 MPa (210-232 ksi) | ASTM E8/E8M | | **Yield Strength (0.2% offset)** | 1300-1450 MPa (189-210 ksi) | ASTM E8/E8M | | **Elongation (4D gauge)** | 9-12% | ASTM E8/E8M | | **Reduction of Area** | 35-45% | ASTM E8/E8M | | **True Fracture Strength** | 1900-2100 MPa | Calculated | ### **4.2 Toughness & Fatigue Properties** | **Property** | **Typical Value** | **Conditions** | |--------------|-------------------|---------------| | **Charpy V-Notch Impact** | 15-25 J (11-18 ft·lb) | Room temperature | | **Fracture Toughness (K_IC)** | 50-65 MPa√m | ASTM E399 | | **Fatigue Limit (Rotating Bending)** | 550-650 MPa | R = -1, polished surface | | **Fatigue Crack Growth Threshold (ΔK_th)** | 5-6 MPa√m | R = 0.1 | ### **4.3 Physical Properties** | **Property** | **Value** | **Unit** | |--------------|-----------|----------| | **Density** | 7.85 | g/cm³ | | **Elastic Modulus** | 205 | GPa | | **Shear Modulus** | 80 | GPa | | **Poisson's Ratio** | 0.29 | — | | **Thermal Conductivity** | 41.5 | W/m·K | | **Specific Heat** | 460 | J/kg·K | | **Thermal Expansion Coefficient** | 12.0 × 10^-6 | /K (20-100°C) | ## **5. HARDENABILITY DATA (JOMINY END-QUENCH)** ### **5.1 Hardness Profile** | **Distance from Quenched End** | **Hardness (HRC)** | |--------------------------------|---------------------| | 1.5 mm (1/16 in.) | 48-51 | | 3.0 mm (1/8 in.) | 47-50 | | 6.0 mm (1/4 in.) | 45-48 | | 9.0 mm (3/8 in.) | 44-47 | | 12.5 mm (1/2 in.) | 43-46 | | 19.0 mm (3/4 in.) | 41-44 | | 25.4 mm (1 in.) | 39-42 | *Boron-enhanced hardenability allows consistent hardening of larger sections* ## **6. APPLICATIONS** ### **6.1 Primary Industries** - **Automotive:** High-strength fasteners, suspension components, steering parts - **Heavy Equipment:** Undercarriage components, track links, hydraulic parts - **Oil & Gas:** Valve components, drilling tool parts, downhole equipment - **Defense:** Armor components, weapon system parts, vehicle components - **Industrial Machinery:** High-stress shafts, gears, couplings ### **6.2 Specific Components** | **Component Type** | **Typical Size Range** | **Key Benefit** | |-------------------|------------------------|-----------------| | **High-Strength Bolts** | M12-M36 | Consistent high clamp load | | **Hydraulic Rods** | 25-100 mm diameter | Wear resistance, strength | | **Gear Blanks** | Up to 150 mm | Uniform properties for finishing | | **Bearing Components** | Various | Hardness and dimensional stability | | **Tooling Components** | Various | Wear life, strength | ## **7. PROCESSING CHARACTERISTICS** ### **7.1 Machinability** - **Relative Machinability:** 50% (compared to 100% for 1212 steel) - **Cutting Speed:** 60-80 m/min with coated carbide - **Feed Rate:** 0.15-0.25 mm/rev - **Tool Material:** PVD-coated carbide or cermet recommended - **Coolant:** High-pressure coolant recommended ### **7.2 Weldability** | **Parameter** | **Rating/Value** | |---------------|------------------| | **Carbon Equivalent (CE)** | 0.45-0.50 | | **Weldability Rating** | Poor (Pre/post heat required) | | **Preheat Temperature** | 200-250°C (400-480°F) | | **Post-Weld Heat Treatment** | 150°C temper recommended | | **Electrode Type** | Low-hydrogen (AWS E10018-D2) | ### **7.3 Grinding & Finishing** - **Surface Finish:** Can achieve Ra < 0.4 µm with proper grinding - **Grinding Burn Risk:** Moderate (monitor with Nital etch) - **Recommended Wheel:** Aluminum oxide or CBN for production ## **8. COMPARATIVE PERFORMANCE** ### **8.1 vs. Higher Temperature Tempering** | **Property** | **150°C Temper** | **300°C Temper** | |--------------|------------------|------------------| | **Hardness** | 44-48 HRC | 38-42 HRC | | **Tensile Strength** | 1450-1600 MPa | 1200-1350 MPa | | **Impact Toughness** | 15-25 J | 30-40 J | | **Dimensional Stability** | Excellent | Very Good | | **Stress Relief** | Partial | Complete | ### **8.2 vs. Carburized Condition** | **Aspect** | **SQ&T 150°C** | **Carburized & Hardened** | |------------|----------------|---------------------------| | **Surface Hardness** | 44-48 HRC | 58-63 HRC | | **Core Hardness** | 44-48 HRC | 35-42 HRC | | **Case Depth** | Full section | 0.5-2.0 mm | | **Compressive Stresses** | Moderate | Very High | | **Production Cost** | Lower | Higher | ## **9. QUALITY ASSURANCE & TESTING** ### **9.1 Mandatory Testing** 1. **Chemical Analysis:** Spectrographic verification per heat 2. **Hardness Testing:** Brinell/Rockwell at multiple locations 3. **Microstructure:** Martensitic structure verification (ASTM E112) 4. **Non-Destructive Testing:** MPI or UT as specified ### **9.2 Optional Testing** - **Tensile Testing:** Full characterization - **Impact Testing:** Charpy V-notch at specified temperatures - **Hardenability Verification:** Jominy end-quench test - **Microcleanliness:** Per ASTM E45 ## **10. DESIGN CONSIDERATIONS** ### **10.1 Section Size Limitations** - **Maximum Hardened Diameter:** 75 mm (3 in.) for full hardness - **Minimum Effective Section:** 10 mm (0.4 in.) for uniform properties - **Hardenability Factor (DI):** Approximately 70 mm (2.75 in.) ### **10.2 Service Temperature Limits** - **Maximum Continuous Service:** 200°C (390°F) - **Short-Term Exposure:** Up to 250°C (480°F) for <100 hours - **Low-Temperature Service:** -40°C (-40°F) with proper design ## **11. TECHNICAL ADVANTAGES** 1. **Cost Efficiency:** Single quench process reduces energy and processing time 2. **Uniform Properties:** Consistent through-section characteristics 3. **Dimensional Stability:** Minimal distortion compared to carburizing 4. **Predictable Performance:** H-steel consistency ensures reliable behavior 5. **Simplified Processing:** No carburizing atmosphere control required ## **12. STORAGE & HANDLING** - **Surface Protection:** VCI paper or rust preventive oil recommended - **Storage Environment:** Dry, temperature-controlled conditions - **Shelf Life:** 12 months with proper packaging - **Handling:** Use non-marring lifting equipment to prevent surface damage --- **NOTES:** 1. All mechanical property data are typical values for 25 mm diameter sections 2. Larger sections may exhibit lower core hardness values 3. Actual properties may vary based on section size and quenching parameters 4. This specification should be supplemented with application-specific testing for critical uses 5. Consult with metallurgical engineers for component-specific heat treatment optimization **REVISION:** 1.0 | **DATE:** 2024 | **STATUS:** Released -:- For detailed product information, please contact sales. -: AISI 4419H Steel, single quenched and tempered, 150°C (300°F) Specification Dimensions Size： Diameter 20-1000 mm Length <5619 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 4419H Steel, single quenched and tempered, 150°C (300°F) Properties -:- For detailed product information, please contact sales. -:

Applications of AISI 4419H Steel, single quenched and tempered, 150°C (300°F) -:- For detailed product information, please contact sales. -: Chemical Identifiers AISI 4419H Steel, single quenched and tempered, 150°C (300°F) -:- For detailed product information, please contact sales. -:

Packing of AISI 4419H Steel, single quenched and tempered, 150°C (300°F) -:- 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 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 2090 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