AISI 4028H Electrical Furnace Alloy 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 4028H Electrical Furnace Alloy Steel Flange, Composition Spec Product Information -:- For detailed product information, please contact sales. -: AISI 4028H Electrical Furnace Alloy Steel Flange, Composition Spec Synonyms -:- For detailed product information, please contact sales. -:

AISI 4028H Electrical Furnace Alloy Steel, Composition Spec Product Information -:- For detailed product information, please contact sales. -: # **Product Introduction: AISI 4028H Electric Furnace Alloy Steel** ## **Executive Summary** **AISI 4028H** is a **hardenability-controlled, medium-carbon molybdenum-silicon alloy steel** produced via **electric arc furnace (EAF) melting** with precise composition control. As the H-grade variant of AISI 4028, this material combines the inherent benefits of electric furnace steelmaking—superior cleanliness, precise chemistry control, and reduced impurities—with guaranteed hardenability bands for predictable heat treatment response. The "H" designation ensures consistent through-hardening characteristics across production lots, making it ideal for critical components where dimensional stability, property uniformity, and manufacturing reliability are paramount. This premium-grade material is particularly valued in automotive, industrial machinery, and heavy equipment applications requiring both the metallurgical advantages of EAF production and the processing predictability of hardenability-controlled steel. --- ## **1. Chemical Composition & Manufacturing Control** ### **Controlled Composition Ranges (SAE J1268 Specification)** | Element | Content Range (% by weight) - **AISI 4028H** | EAF Production Advantages & Function | | :--- | :--- | :--- | | **Carbon (C)** | 0.24 - 0.31 | **Precise control via EAF:** Wider range allows hardenability optimization; provides core strength foundation | | **Molybdenum (Mo)** | 0.15 - 0.35 | **Reduced variability:** EAF enables exact Mo additions; enhances hardenability, grain refinement, temper resistance | | **Silicon (Si)** | 0.20 - 0.35 | **Superior deoxidation:** EAF allows optimal Si control; solid solution strengthener, improves hardenability | | **Manganese (Mn)** | 0.60 - 1.00 | **Consistent recovery:** EAF provides predictable Mn yield; hardenability enhancer, deoxidizer | | **Phosphorus (P)** | 0.025 max | **Enhanced purity:** EAF + secondary refining enables ultra-low P; improves ductility and impact toughness | | **Sulfur (S)** | 0.025 max | **Exceptional control:** EAF with desulfurization achieves very low S; enhances transverse properties | | **Aluminum (Al)** | 0.010 - 0.050 | **Precise grain control:** EAF allows exact Al additions for consistent grain size control | | **Copper (Cu)** | 0.35 max | **Scrap control:** EAF enables Cu limitation; prevents hot shortness issues | | **Nickel (Ni)** | 0.25 max | **Residual control:** EAF scrap management controls Ni; prevents unwanted hardenability effects | | **Chromium (Cr)** | 0.25 max | **Residual control:** Controlled via scrap selection; prevents excessive hardenability | | **Tin (Sn)** | 0.03 max | **Enhanced purity:** EAF scrap management minimizes detrimental residuals | | **Iron (Fe)** | Balance | **Cleaner matrix:** EAF production reduces non-metallic inclusions | ### **Electric Furnace Production Advantages** - **Superior Cleanliness:** Lower oxygen and sulfur content through precise slag control - **Reduced Tramp Elements:** Better control over copper, tin, and other residuals via scrap selection - **Consistent Chemistry:** Computer-controlled alloy additions for batch-to-batch consistency - **Improved Inclusion Control:** Spherical, finely dispersed inclusions through calcium treatment - **Enhanced Purity:** Lower phosphorus and sulfur through secondary refining (Ladle Metallurgy) ### **Hardenability Control Philosophy** - **Jominy Certification:** Each heat undergoes standardized end-quench testing - **Band Guarantee:** Chemistry adjusted within ranges to achieve specified hardenability bands - **Production Optimization:** Different heats achieve identical Jominy curves through controlled chemistry variation - **Predictable Performance:** Engineers can design with exact hardening characteristics --- ## **2. Physical & Mechanical Properties** ### **A. Fundamental Physical Properties (EAF Enhanced)** | Property | Condition | Value/Range | EAF Advantages | | :--- | :--- | :--- | :--- | | **Density** | All conditions | 7.85 g/cm³ | More consistent due to controlled chemistry | | **Elastic Modulus** | Tempered | 200-205 GPa | Improved consistency | | **Thermal Conductivity** | 100°C | 43.5 W/m·K | More predictable due to consistent microstructure | | **Electrical Resistivity** | 20°C | 0.23 μΩ·m | Lower variability | | **Cleanness Rating** | - | ASTM E45: B1, C1, D1 typical | **Superior inclusion control** | | **Grain Size** | Normalized | ASTM 6-8 | **Consistent fine grains** | ### **B. Guaranteed Hardenability Characteristics (Jominy Test)** #### **Typical Hardenability Bands for AISI 4028H** | Jominy Distance | Hardness Range (HRC) | Section Size Equivalent | | :--- | :--- | :--- | | **1/16" (1.6 mm)** | 40-47 | Surface of small components | | **1/4" (6.4 mm)** | 33-40 | Moderate sections | | **1/2" (12.7 mm)** | 28-35 | Core of case-hardened parts | | **1" (25.4 mm)** | 22-30 | Through-hardening capability | | **2" (50.8 mm)** | 18-25 | Maximum effective depth | #### **Critical Diameter Calculations** - **Ideal Critical Diameter (D_I):** 1.9-2.5 inches (48-64 mm) in oil - **95% Martensite (D₉₅):** 1.3-1.9 inches (33-48 mm) - **50% Martensite (D₅₀):** 1.9-2.6 inches (48-66 mm) ### **C. Mechanical Properties by Condition** #### **1. Annealed/Normalized (EAF Enhanced)** - **Hardness:** 163-207 HB (tighter range than conventional) - **Tensile Strength:** 550-690 MPa - **Yield Strength:** 380-550 MPa - **Elongation:** 24-28% (**improved due to lower P, S**) - **Reduction of Area:** 58-65% (**enhanced ductility**) - **Transverse Impact:** 45-60 J (**superior to conventional**) #### **2. Through-Hardened Properties** *Austenitize: 830-850°C, Oil Quench, Temper* | Tempering Temperature | Hardness (HRC) | Tensile Strength | Charpy Impact | | :--- | :--- | :--- | :--- | | **205°C** | 46-51 | 1550-1700 MPa | 30-45 J | | **425°C** | 36-41 | 1200-1350 MPa | 45-65 J | | **540°C** | 29-34 | 1000-1150 MPa | 65-85 J | | **650°C** | 23-28 | 800-950 MPa | 85-105 J | #### **3. Case-Hardened Properties** *Carburized: 0.8-1.5mm case, Oil Quench, Temper 150-200°C* | Property | Typical Range | EAF Advantage | | :--- | :--- | :--- | | **Core Hardness** | 34-40 HRC | More consistent | | **Case Hardness** | 60-63 HRC | Uniform gradient | | **Fatigue Strength** | 500-600 MPa | Improved due to cleaner steel | | **Contact Fatigue Life** | +15-25% vs. conventional | Enhanced inclusion control | ### **D. Special EAF-Enhanced Properties** - **Improved Fatigue Performance:** Cleaner steel with fewer inclusion-initiated failures - **Better Transverse Properties:** Lower sulfur improves ductility and impact across directions - **Enhanced Machinability:** Consistent hardness and microstructure - **Superior Surface Finish:** Reduced inclusion-related surface defects - **Consistent Response:** Predictable behavior in heat treatment and machining --- ## **3. International Standards & Specifications** ### **Primary Governing Standards** | Standard/Organization | Designation | Title/Scope | | :--- | :--- | :--- | | **SAE International** | **SAE J1268** | Hardenability Bands for Carbon and Alloy H-Steels | | **SAE International** | **SAE J1868** | Standard Hardness and Hardenability Requirements | | **ASTM International** | **ASTM A304** | Steel Bars Subject to End-Quench Hardenability | | **ASTM International** | **ASTM A29/A29M** | With H-grade supplement | | **ASTM International** | **ASTM A534** | Carburizing Steels (when applicable) | | **UNS** | **H40280** | Unified Numbering System | ### **EAF-Specific Quality Standards** | Standard | Application | Benefit | | :--- | :--- | :--- | | **ASTM E45** | Inclusion Rating | Method A preferred for EAF cleanliness assessment | | **ASTM E112** | Grain Size | Consistent fine grain structure | | **SEP 1571** | Microcleanliness | Quantitative inclusion assessment | | **ISO 4967** | Non-metallic Inclusions | International cleanness standard | ### **International Equivalents & Production Methods** | Country/Region | Equivalent Concept | Production Method | | :--- | :--- | :--- | | **European Union** | **Similar EAF H-steels** | EAF + Ladle Furnace common | | **Japan** | **Special Quality EAF steels** | Often produced via EAF route | | **Germany** | **EF + LF produced steels** | Common for quality applications | | **China** | **EAF-produced H-grades** | Increasingly common | | **General Note** | **EAF production is global standard for quality H-steels** | - | --- ## **4. Product Applications & Industries** ### **EAF Production Justification for Specific Applications** #### **1. Automotive (Premium Applications)** - **Transmission Components:** Synchronizer hubs, gear clusters requiring consistent hardening - **Steering Systems:** Steering arms, pitman arms where fatigue life is critical - **Engine Components:** Balance shafts, camshafts requiring high reliability - **Drivetrain:** Axle shafts for premium vehicles - **Justification:** Enhanced fatigue performance and consistency justify EAF premium #### **2. Heavy Equipment & Machinery** - **Gearbox Components:** Industrial gears subject to high cyclic loading - **Hydraulic Components:** Piston rods, cylinder rods for high-pressure systems - **Mining Equipment:** Crusher parts requiring maximum reliability - **Construction Machinery:** Final drive components - **Justification:** Improved transverse properties and fatigue resistance #### **3. Aerospace & Defense (Non-flight critical)** - **Landing Gear Components:** For lighter aircraft - **Missile Components:** Structural parts requiring consistency - **Ground Support Equipment:** Critical moving parts - **Justification:** Predictable properties and documentation #### **4. Industrial Manufacturing** - **Machine Tool Components:** Spindles, arbors requiring precision - **Power Transmission:** High-reliability shafts and couplings - **Material Handling:** Critical conveyor components - **Justification:** Consistent machining and heat treatment response ### **Economic Justification for EAF 4028H** - **Reduced Failure Rates:** Cleaner steel minimizes inclusion-related failures - **Lower Inspection Costs:** Consistent properties reduce testing requirements - **Improved Process Yield:** Predictable behavior increases manufacturing efficiency - **Extended Component Life:** Enhanced fatigue performance increases service life - **Warranty Reduction:** Fewer field failures decrease warranty costs --- ## **5. Heat Treatment Technology with EAF Advantages** ### **A. Enhanced Heat Treatment Consistency** **EAF benefits in heat treatment:** - **Uniform Austenitizing:** Consistent chemistry promotes even transformation - **Predictable Quenching:** Controlled hardenability enables precise quenching parameters - **Minimized Distortion:** Uniform properties reduce thermal stress variations - **Consistent Tempering:** Predictable response to tempering temperatures ### **B. Certified Hardenability in Practice** Each lot includes: 1. **Actual Jominy Curve:** Showing tested values within guaranteed bands 2. **Heat-Specific Data:** For precise process calculation 3. **Statistical Analysis:** Demonstrating consistency within heat 4. **Quality Documentation:** Complete traceability ### **C. Recommended Heat Treatment Parameters** #### **Through-Hardening Applications** - **Austenitizing:** 830-850°C (1525-1560°F) - **Soak Time:** Based on section size and certified hardenability - **Quenching:** Oil, parameters calculated from Jominy data - **Tempering:** Immediately after quenching #### **Case Hardening Applications** - **Carburizing:** 900-930°C with precise atmosphere control - **Case Depth:** Optimized based on hardenability data - **Quenching:** From appropriate temperature based on case requirements - **Tempering:** 150-200°C for stress relief ### **D. EAF-Specific Heat Treatment Advantages** - **Reduced Decarburization:** Cleaner surfaces respond better to protective atmospheres - **Uniform Case Depth:** Consistent chemistry promotes even carburizing - **Minimized Distortion:** Predictable transformation reduces warpage - **Optimized Properties:** Can target specific property combinations reliably --- ## **6. Manufacturing & Fabrication Characteristics** ### **A. Machinability (EAF Enhanced)** - **Rating:** 60-65% of B1112 - **EAF Advantages:** - Consistent hardness and microstructure - Predictable tool wear patterns - Improved surface finish capability - Reduced variability in machining parameters - **Recommended Practices:** - **Turning:** 75-110 m/min with carbide - **Drilling:** 20-30 m/min with HSS - **Coolant:** Essential for optimal results ### **B. Weldability (with Precautions)** **Rating: FAIR (improved over conventional due to lower S, P)** #### **EAF Welding Advantages** - Reduced hot cracking tendency (lower S) - Better HAZ toughness (lower P) - More predictable HAZ hardenability #### **Welding Recommendations** 1. **Preheat:** 150-250°C based on thickness 2. **Filler:** Low-hydrogen electrodes 3. **PWHT:** Stress relief recommended 4. **Process:** GTAW or SMAW with low-hydrogen ### **C. Quality Assurance in Manufacturing** **EAF advantages for manufacturers:** - Reduced incoming inspection requirements - Predictable processing parameters - Lower scrap rates - Improved final quality consistency - Enhanced traceability --- ## **7. Design & Engineering Advantages** ### **A. Technical Advantages of EAF 4028H** 1. **Predictable Performance:** Certified hardenability eliminates guesswork 2. **Enhanced Properties:** Cleaner steel improves fatigue and impact resistance 3. **Consistent Quality:** Reduced lot-to-lot variability 4. **Optimized Design:** Allows design to specific property requirements 5. **Documented Properties:** Complete traceability and certification ### **B. Design Considerations** - **Section Size Optimization:** Design to maximum effective hardening depth - **Fatigue Design:** Can utilize improved fatigue properties - **Safety Factors:** Can be optimized due to material consistency - **Quality Integration:** Design for manufacturing with predictable material behavior ### **C. Economic Justification** **Cost Premium vs. Conventional 4028H:** - **Material Cost:** 15-30% premium for EAF production - **Savings Achieved:** - Reduced scrap: 3-8% - Lower inspection: 2-5% - Improved yield: 5-10% - Reduced warranty: 2-6% - **Net Effect:** Often cost-neutral or savings in total cost --- ## **8. Comparative Analysis** ### **EAF 4028H vs. Conventional 4028H** | Parameter | Conventional 4028H | EAF 4028H | Advantage | | :--- | :--- | :--- | :--- | | **Sulfur Content** | 0.040 max | 0.025 max | **Improved transverse properties** | | **Phosphorus Content** | 0.035 max | 0.025 max | **Better impact toughness** | | **Inclusion Control** | Standard | Enhanced | **Superior fatigue performance** | | **Chemistry Consistency** | Good | Excellent | **Reduced variability** | | **Hardenability Band Width** | Standard | Tighter potential | **More precise control** | | **Cost** | Base | 15-30% premium | **Justified by total cost savings** | ### **EAF 4028H vs. Other Premium Materials** | Material | Key Advantages | Typical Cost Premium | Best Applications | | :--- | :--- | :--- | :--- | | **EAF 4028H** | Balance of cost and performance | 1.0x (baseline) | Quality-critical automotive/industrial | | **8620H** | Superior toughness | 1.5-2.0x | Critical gears, high impact | | **4320H** | Excellent fatigue | 2.0-2.5x | High-performance applications | | **Vacuum Melted** | Ultimate cleanliness | 3.0-5.0x | Aerospace, bearing applications | --- ## **9. Technical Summary & Selection Guidelines** ### **When to Specify EAF 4028H** 1. **Quality-Critical Components:** Where failure has significant consequences 2. **High-Volume Production:** Where consistency reduces total cost 3. **Fatigue-Limited Applications:** Where cleaner steel extends life 4. **Precision Manufacturing:** Where predictable behavior is essential 5. **Regulated Industries:** Where documentation and traceability are required ### **Optimal Application Characteristics** - **Component Size:** Sections up to 65mm requiring through-hardening - **Production Volume:** Medium to high volume justifying EAF premium - **Quality Requirements:** Industries with stringent quality standards - **Performance Needs:** Applications benefiting from improved fatigue life - **Total Cost Focus:** Where total cost optimization is more important than material cost ### **Selection Decision Tree** ``` Component Criticality → High → Need Consistency → Yes → EAF 4028H ↓ ↓ Low No ↓ ↓ Production Volume Conventional 4028H ↓ High ↓ Total Cost Analysis ↓ Justifies Premium → Yes → EAF 4028H ↓ No ↓ Conventional 4028H ``` --- ## **10. Future Developments & Industry Trends** ### **A. Technological Advancements** 1. **Digital Integration:** Hardenability data in digital twin manufacturing systems 2. **Predictive Analytics:** AI-based prediction of optimal heat treatment parameters 3. **Advanced EAF Technologies:** Further reduction of residuals and inclusions 4. **Sustainable Production:** Lower carbon footprint EAF processes ### **B. Market Trends** - **Increased Adoption:** Growing in quality-critical automotive applications - **Global Standardization:** More consistent specifications internationally - **Supply Chain Integration:** Closer links between steel producers and component manufacturers - **Quality Documentation:** Digital quality certificates with complete data ### **C. Sustainability Aspects** - **Recycled Content:** EAF typically uses 90-100% scrap steel - **Energy Efficiency:** Modern EAFs are highly energy efficient - **Emissions Control:** Advanced filtration reduces environmental impact - **Circular Economy:** Supports steel recycling infrastructure --- **AISI 4028H Electric Furnace Alloy Steel** represents the premium tier of hardenability-controlled steels, combining the metallurgical advantages of electric furnace production with the processing predictability of certified hardenability bands. This material offers manufacturers not just a steel grade, but a comprehensive engineering solution with documented properties, predictable behavior, and enhanced performance characteristics. While commanding a premium over conventionally produced steels, EAF 4028H delivers significant value through improved manufacturing efficiency, reduced failure rates, and enhanced component performance. For applications where reliability, consistency, and total cost of ownership are paramount—particularly in automotive, heavy equipment, and quality-critical industrial components—EAF 4028H provides an optimal balance of performance, predictability, and value that justifies its specification in demanding engineering applications. -:- For detailed product information, please contact sales. -: AISI 4028H Electrical Furnace Alloy Steel, Composition Spec Specification Dimensions Size： Diameter 20-1000 mm Length <4020 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 4028H Electrical Furnace Alloy Steel, Composition Spec Properties -:- For detailed product information, please contact sales. -:

Applications of AISI 4028H Electrical Furnace Alloy Steel Flange, Composition Spec -:- For detailed product information, please contact sales. -: Chemical Identifiers AISI 4028H Electrical Furnace Alloy Steel Flange, Composition Spec -:- For detailed product information, please contact sales. -:

Packing of AISI 4028H Electrical Furnace Alloy Steel Flange, Composition Spec -:- 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 491 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