AISI 4422 Steel Seamless tube

AISI 4422 Steel Seamless tube, heat treated in 25 mm rounds, reheated to 775°C (1425°F), 150°C (300°F) temper Product Information -:- For detailed product information, please contact sales. -: AISI 4422 Steel Seamless tube, heat treated in 25 mm rounds, reheated to 775°C (1425°F), 150°C (300°F) temper Synonyms -:- For detailed product information, please contact sales. -:

AISI 4422 Steel, heat treated in 25 mm rounds, reheated to 775°C (1425°F), 150°C (300°F) temper Product Information -:- For detailed product information, please contact sales. -: # **AISI 4422 Steel - Heat Treated Round Bars** ## **25mm Diameter, Quenched & Low-Temperature Tempered Condition** --- ### **1. PRODUCT OVERVIEW** **AISI 4422 Alloy Steel - Heat Treated Condition** - **Product Form:** 25mm (1 inch) diameter round bars - **Material Standard:** AISI 4422 / SAE 4422 - Molybdenum Alloy Steel - **Special Heat Treatment:** - **Reheating:** 775°C (1425°F) - Complete austenitization - **Quenching:** Rapid cooling (typically oil quench) - **Tempering:** 150°C (300°F) - Low temperature stress relief - **Resulting Condition:** High hardness, high strength, moderate toughness - **Primary Application:** Components requiring maximum wear resistance and high strength with controlled impact resistance **Material Classification:** - **Type:** Through-hardening alloy steel - **Category:** Medium carbon, low-alloy molybdenum steel - **Key Characteristic:** Good hardenability with molybdenum addition for strength retention --- ### **2. CHEMICAL COMPOSITION** | Element | AISI 4422 Standard Range (%) | Typical Heat Analysis (%) | Metallurgical Function | |---------|-----------------------------|---------------------------|------------------------| | **Carbon (C)** | 0.20-0.25 | 0.22-0.24 | Provides strength and hardenability | | **Manganese (Mn)** | 0.70-0.90 | 0.75-0.85 | Enhances hardenability and strength | | **Phosphorus (P)** | ≤ 0.035 | ≤ 0.025 | Residual element (controlled) | | **Sulfur (S)** | ≤ 0.040 | ≤ 0.030 | Residual element (controlled) | | **Silicon (Si)** | 0.20-0.35 | 0.25-0.30 | Deoxidizer, solid solution strengthener | | **Molybdenum (Mo)** | 0.45-0.60 | 0.50-0.55 | **Primary alloy:** Increases hardenability, strength at elevated temperatures | | **Nickel (Ni)** | - | ≤ 0.25 | Residual (if present) | | **Chromium (Cr)** | - | ≤ 0.20 | Residual (if present) | | **Iron (Fe)** | Balance | Balance | Matrix element | **Note:** AISI 4422 is primarily a molybdenum steel with minimal chromium content, distinguishing it from chromium-molybdenum grades like 4140/42xx series. --- ### **3. MATERIAL SPECIFICATIONS & STANDARDS** | Standard | Number | Title | Relevance | |----------|--------|-------|-----------| | **AISI/SAE** | 4422 | Standard Grade Designation | Primary specification | | **ASTM** | A322 | Standard Specification for Steel Bars, Alloy, Standard Grades | General bar requirements | | **ASTM** | A29/A29M | Standard Specification for Steel Bars, Carbon and Alloy | Quality requirements | | **AMS** | - | *Note: No direct AMS equivalent* | - | | **UNS** | G44220 | Unified Numbering System | Material identification | | **DIN** | 1.7213 | 25MoCr4 | Similar European grade | | **ISO** | 683-11 | Heat-treatable steels, alloy steels | International classification | **Heat Treatment Standards:** - **Austenitizing:** ASTM A255 (Standard Test Methods for Determining Hardenability of Steel) - **Tempering:** ASTM E8 (Standard Test Methods for Tension Testing of Metallic Materials) - **Hardness Testing:** ASTM E18 (Standard Test Methods for Rockwell Hardness) --- ### **4. HEAT TREATMENT DETAILS** #### **Applied Treatment for 25mm Rounds:** 1. **Austenitizing:** - Temperature: 775°C (1425°F) ±10°C - Soaking Time: 60-90 minutes (for 25mm diameter) - Atmosphere: Protective or neutral to prevent decarburization 2. **Quenching:** - Medium: Fast oil quench (typically ISO VG 68 or equivalent) - Agitation: Moderate to ensure uniform cooling - Result: Martensitic transformation throughout cross-section 3. **Tempering:** - Temperature: 150°C (300°F) ±10°C - Duration: 60-120 minutes (minimum 1 hour per inch of thickness) - Cooling: Air cool to room temperature #### **Microstructural Characteristics:** - **Primary Phase:** Tempered martensite (very fine) - **Carbide Type:** Fine iron carbides (ε-carbide) and alloy carbides - **Prior Austenite Grain Size:** ASTM 7-9 (fine grain) - **Retained Austenite:** <5% (typical for this tempering temperature) - **Through-Hardening:** Complete martensitic transformation in 25mm section --- ### **5. MECHANICAL PROPERTIES (AFTER HEAT TREATMENT)** #### **Tensile Properties (Longitudinal):** | Property | Typical Value | Testing Standard | Notes | |----------|---------------|------------------|-------| | **Tensile Strength** | 1550-1750 MPa (225-255 ksi) | ASTM E8/E8M | Very high strength | | **Yield Strength (0.2% offset)** | 1350-1550 MPa (195-225 ksi) | ASTM E8/E8M | Excellent yield ratio | | **Elongation in 4D** | 8-12% | ASTM E8/E8M | Moderate ductility | | **Reduction of Area** | 30-45% | ASTM E8/E8M | Impact energy absorption capability | | **Modulus of Elasticity** | 205 GPa (29.7×10⁶ psi) | - | Standard for steel | #### **Hardness & Toughness:** | Property | Typical Value | Testing Standard | Notes | |----------|---------------|------------------|-------| | **Surface Hardness** | 48-52 HRC | ASTM E18 | Uniform across diameter | | **Core Hardness (center)** | 47-51 HRC | ASTM E18 | Excellent through-hardening | | **Charpy V-Notch Impact** | 20-35 J (15-26 ft-lb) at 20°C | ASTM E23 | Moderate toughness | | **Fatigue Strength** | ~600-700 MPa (rotating bending) | - | Good fatigue resistance | #### **Hardness Profile (25mm Diameter - Predicted):** | Position from Surface | Hardness (HRC) | Microstructure | |----------------------|----------------|---------------| | Surface (0mm) | 48-52 HRC | Fully tempered martensite | | 1/4 Radius (3.125mm) | 48-52 HRC | Fully tempered martensite | | 1/2 Radius (6.25mm) | 48-52 HRC | Fully tempered martensite | | Center (12.5mm) | 47-51 HRC | Fully tempered martensite | --- ### **6. PHYSICAL PROPERTIES (HEAT TREATED CONDITION)** | Property | Value | Conditions / Notes | |----------|-------|-------------------| | **Density** | 7.85 g/cm³ | At 20°C | | **Melting Range** | 1480-1520°C | Approximate | | **Thermal Conductivity** | 42.5 W/m·K | At 100°C | | **Specific Heat Capacity** | 475 J/kg·K | At 20°C | | **Coefficient of Thermal Expansion** | 12.2 × 10⁻⁶/K | 20-100°C range | | **Electrical Resistivity** | 0.22 μΩ·m | At 20°C | | **Magnetic Properties** | Ferromagnetic | Below Curie temperature | --- ### **7. TYPICAL APPLICATIONS** #### **High-Strength Fasteners & Components:** - **Heavy-Duty Bolts:** Grade 10.9 and higher equivalent fasteners - **High-Strength Studs:** For pressure vessels and structural applications - **Load-Bearing Pins:** Axle pins, hinge pins, coupling pins - **Shear Pins:** Designed to fail at specific loads #### **Wear-Resistant Components:** - **Agricultural Parts:** Plow shares, cultivator teeth - **Mining Tools:** Drill bits, cutter teeth - **Earth-Moving Equipment:** Track links, bucket teeth adapters - **Wear Plates:** High abrasion resistance applications #### **Tooling & Machinery Components:** - **Jigs & Fixtures:** Precision locating pins, wear plates - **Machine Tool Parts:** Spindle shafts, arbors (where moderate toughness suffices) - **Die Components:** Punch holders, stripper plates - **Gauges & Measuring Tools:** Where dimensional stability is critical #### **Automotive & Transportation:** - **High-Stress Bolts:** Wheel bolts, suspension bolts - **Transmission Components:** Shift forks, selector shafts - **Heavy Truck Parts:** Fifth wheel components, suspension pins --- ### **8. PROCESSING CHARACTERISTICS (HEAT TREATED STATE)** #### **Machinability:** - **Rating:** Poor (25-35% of free-cutting steel) - **Recommended Tools:** Premium carbide grades (P20-P40), CBN for finishing - **Cutting Parameters:** Low speeds, moderate feeds, heavy roughing cuts preferred - **Cooling:** Essential - use copious cutting fluid - **Grindability:** Good with proper wheel selection (aluminum oxide or CBN) #### **Secondary Operations:** - **Straightening:** Possible with controlled hydraulic presses (avoid impact) - **Surface Finishing:** Grinding, honing, or superfinishing recommended - **Coating:** Suitable for various coatings (phosphate, black oxide, electroplating) - **Stress Relieving:** May benefit from additional stress relief at 150-200°C if precision machining is required #### **Weldability:** - **Rating:** Very Poor (not recommended in heat-treated state) - **If Required:** Must be preheated to 300-400°C and post-weld tempered - **Preferred Method:** GTAW (TIG) with matching composition filler - **Risk:** High probability of cracking without proper procedure --- ### **9. HEAT TREATMENT ALTERNATIVES** *For Different Property Requirements:* | Tempering Temperature | Resulting Hardness (HRC) | Tensile Strength (MPa) | Primary Application | |----------------------|--------------------------|------------------------|----------------------| | **150°C (300°F)** | 48-52 | 1550-1750 | **This specification** - Max wear resistance | | **200°C (390°F)** | 45-49 | 1400-1550 | Improved toughness with high strength | | **315°C (600°F)** | 40-44 | 1200-1350 | Good strength-toughness balance | | **425°C (800°F)** | 35-39 | 1000-1150 | Enhanced impact resistance | | **540°C (1000°F)** | 30-34 | 850-950 | Maximum toughness | --- ### **10. QUALITY ASSURANCE & TESTING** #### **Standard Testing Protocol:** 1. **Chemical Analysis:** Optical emission spectroscopy 2. **Hardness Testing:** Multiple points (surface, mid-radius, center) 3. **Microstructural Examination:** Grain size, martensite quality 4. **Surface Integrity:** Magnetic particle or dye penetrant inspection 5. **Dimensional Verification:** Diameter, roundness, straightness #### **Certification Requirements:** - Heat number traceability - Chemical analysis report - Heat treatment record (temperature/time logs) - Mechanical test results (hardness, typically) - Compliance statement to ASTM A322/A29 --- ### **11. TECHNICAL CONSIDERATIONS** #### **Design Advantages:** 1. **High Strength-to-Weight Ratio:** Excellent for weight-sensitive applications 2. **Good Wear Resistance:** Suitable for abrasive environments 3. **Dimensional Stability:** Low tempering temperature minimizes distortion 4. **Uniform Properties:** Through-hardened cross-section #### **Design Limitations:** 1. **Limited Toughness:** Not suitable for high-impact applications 2. **Stress Corrosion Sensitivity:** High hardness increases susceptibility 3. **Notch Sensitivity:** Careful design of stress concentrators required 4. **Limited Machinability:** Difficult to machine in hardened state #### **Environmental Considerations:** - **Operating Temperature:** Maximum continuous service ~200°C - **Corrosion Resistance:** Similar to plain carbon steel - requires protection - **Hydrogen Embrittlement Risk:** High for electroplated components --- ### **12. COMPARISON WITH SIMILAR GRADES** | Grade | C% Range | Key Alloy | Typical Hardness (HRC) after similar HT | Relative Cost | Primary Distinction | |-------|----------|-----------|-----------------------------------------|---------------|---------------------| | **AISI 4422** | 0.20-0.25 | Mo (0.45-0.60%) | 48-52 | Medium | Good value for molybdenum hardenability | | **AISI 4140** | 0.38-0.43 | Cr-Mo | 50-54 | Medium | Higher carbon for more wear resistance | | **AISI 4340** | 0.38-0.43 | Ni-Cr-Mo | 50-54 | High | Nickel addition for better toughness | | **AISI 8620** | 0.18-0.23 | Ni-Cr-Mo | 40-45 (case) | Medium | Case-hardening grade | | **AISI 1045** | 0.43-0.50 | Carbon only | 52-56 | Low | Lower hardenability, less tough | --- ### **13. PACKAGING & HANDLING** #### **Standard Packaging for 25mm Rounds:** - **Bundle Configuration:** Strapped bundles of 1-3 metric tons - **Protection:** Rust preventive oil or VCI paper wrap - **Marking:** Heat number, grade (4422), size, hardness range - **End Identification:** Color-coded for grade and condition #### **Safety Considerations:** - **Hardness Hazard:** Material is extremely hard - handle with care - **Brittleness Risk:** May fracture under impact loading - **Sharp Edges:** Machined surfaces can be extremely sharp - **Grinding Precautions:** Use appropriate PPE for dust control --- **TECHNICAL SUMMARY:** AISI 4422 steel in this specific heat-treated condition (775°C austenitize + 150°C temper) provides an optimal balance of high strength and wear resistance for 25mm diameter components. The molybdenum content ensures adequate hardenability for full through-hardening at this diameter, while the low tempering temperature maintains maximum hardness. This material is particularly suitable for applications where wear resistance is prioritized over impact toughness, and where dimensional stability under load is critical. **APPLICATION NOTE:** For dynamic loading applications or where impact resistance is required, consider increasing the tempering temperature to 200-315°C to improve toughness at the expense of some hardness and strength. **DISCLAIMER:** The values provided are typical for properly processed material. Actual properties may vary within standard specification ranges. For critical applications, testing of actual production material is strongly recommended. Consult with a materials engineer for application-specific recommendations. -:- For detailed product information, please contact sales. -: AISI 4422 Steel, heat treated in 25 mm rounds, reheated to 775°C (1425°F), 150°C (300°F) temper Specification Dimensions Size： Diameter 20-1000 mm Length <4069 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 4422 Steel, heat treated in 25 mm rounds, reheated to 775°C (1425°F), 150°C (300°F) temper Properties -:- For detailed product information, please contact sales. -:

Applications of AISI 4422 Steel Seamless tube, heat treated in 25 mm rounds, reheated to 775°C (1425°F), 150°C (300°F) temper -:- For detailed product information, please contact sales. -: Chemical Identifiers AISI 4422 Steel Seamless tube, heat treated in 25 mm rounds, reheated to 775°C (1425°F), 150°C (300°F) temper -:- For detailed product information, please contact sales. -:

Packing of AISI 4422 Steel Seamless tube, heat treated in 25 mm rounds, reheated to 775°C (1425°F), 150°C (300°F) temper -:- 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 Seamless tube 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 540 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