AISI 4028 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 4028 Steel Flange Product Information -:- For detailed product information, please contact sales. -: AISI 4028 Steel Flange Synonyms -:- For detailed product information, please contact sales. -:

AISI 4028 Steel Product Information -:- For detailed product information, please contact sales. -: # **Product Introduction: AISI 4028 Steel** ## **Executive Summary** **AISI 4028** is a **low-carbon, molybdenum-silicon alloy steel** specifically engineered for applications requiring enhanced hardenability and strength beyond standard carbon steels, while maintaining good toughness and ductility. Belonging to the AISI 40xx series, this grade contains **approximately 0.25% carbon** with deliberate additions of **molybdenum (0.20-0.30%) and elevated silicon (0.20-0.35%)**. This combination provides improved hardenability, better temper resistance, and increased strength through solid solution strengthening compared to plain carbon steels like 1028. AISI 4028 is particularly valued for components that require a balance of strength, toughness, and wear resistance, and can be effectively case-hardened or through-hardened depending on the application requirements in automotive, machinery, and general engineering sectors. --- ## **1. Chemical Composition** ### **Standard Composition Ranges** | Element | Content Range (% by weight) - **AISI 4028** | Primary Function | | :--- | :--- | :--- | | **Carbon (C)** | 0.25 - 0.30 | Provides core strength and hardenability; balanced for machinability and effective response to heat treatment | | **Molybdenum (Mo)** | 0.20 - 0.30 | Enhances hardenability, refines grain structure, improves temper resistance, reduces susceptibility to temper embrittlement | | **Silicon (Si)** | 0.20 - 0.35 | **Elevated compared to many grades;** powerful deoxidizer, solid solution strengthener in ferrite, improves hardenability, enhances resistance to softening during tempering | | **Manganese (Mn)** | 0.70 - 0.90 | Deoxidizer, improves hardenability, enhances response to heat treatment | | **Phosphorus (P)** | 0.035 max | Impurity (controlled for ductility) | | **Sulfur (S)** | 0.040 max | Impurity (typically kept low; may be controlled for machinability in special variants) | | **Nickel (Ni)** | - | Not specified; trace amounts may be present | | **Chromium (Cr)** | - | Not specified; trace amounts may be present | | **Iron (Fe)** | Balance | Matrix element | ### **Key Metallurgical Features** - **Silicon Enhancement:** The 0.20-0.35% Si range is notably higher than typical minimums, providing significant solid solution strengthening and improved hardenability - **Hardenability Synergy:** Combined effects of Mo and Si provide better hardenability than either element alone at similar levels - **Temper Resistance:** Both Mo and Si improve resistance to softening during tempering, allowing higher tempering temperatures for improved toughness - **Grain Refinement:** Molybdenum helps control grain growth during high-temperature processing - **Oxidation Resistance:** Silicon contributes to improved scaling resistance at elevated temperatures - **Economic Balance:** Provides enhanced properties over plain carbon steels without nickel or chromium costs --- ## **2. Physical & Mechanical Properties** ### **A. Fundamental Physical Properties** | Property | Condition | Value/Range | Notes | | :--- | :--- | :--- | :--- | | **Density** | All conditions | 7.85 g/cm³ (0.284 lb/in³) | - | | **Melting Point** | - | ~1510°C (2750°F) | Slightly reduced due to alloying elements | | **Elastic Modulus** | Annealed/Tempered | 200-205 GPa (29,000-29,700 ksi) | - | | **Shear Modulus** | - | 80-82 GPa (11,600-11,900 ksi) | - | | **Poisson's Ratio** | - | 0.29 | - | | **Thermal Conductivity** | 100°C | 43.5 W/m·K | Reduced by silicon content | | **Specific Heat Capacity** | 20°C | 475 J/kg·K | - | | **Thermal Expansion Coefficient** | 20-100°C | 11.8 × 10⁻⁶/°C | - | | **Electrical Resistivity** | 20°C | 0.23 μΩ·m | Increased by silicon and molybdenum | | **Magnetic Properties** | Below Curie temp | Ferromagnetic | - | ### **B. Mechanical Properties (Annealed/Normalized Condition)** #### **1. Annealed Condition (For Machining)** - **Hardness:** 163-207 HB (Brinell) - **Tensile Strength:** 550-690 MPa (80-100 ksi) - **Yield Strength (0.2% offset):** 380-550 MPa (55-80 ksi) - **Elongation:** 22-28% in 50mm - **Reduction of Area:** 55-65% - **Charpy V-Notch Impact:** 70-100 J (52-74 ft-lb) at room temperature - **Machinability Rating:** 60-65% of B1112 (Fair to Good) #### **2. Normalized Condition (Improved Consistency)** - **Hardness:** 179-229 HB - **Tensile Strength:** 620-790 MPa (90-115 ksi) - **Yield Strength:** 450-620 MPa (65-90 ksi) - **Elongation:** 20-25% - **Application:** Preferred for parts requiring better dimensional stability during machining ### **C. Heat Treated Properties** #### **1. Through-Hardened Properties (Oil Quenched & Tempered)** *Austenitize: 830-850°C, Oil Quench, Temper as specified* | Tempering Temperature | Hardness (HRC) | Tensile Strength | Yield Strength | Elongation | Impact Energy | | :--- | :--- | :--- | :--- | :--- | :--- | | **205°C (400°F)** | 45-50 | 1500-1650 MPa | 1350-1500 MPa | 8-12% | 25-40 J | | **425°C (800°F)** | 35-40 | 1150-1300 MPa | 1050-1200 MPa | 12-16% | 40-60 J | | **540°C (1000°F)** | 28-33 | 950-1100 MPa | 850-1000 MPa | 16-20% | 60-80 J | | **650°C (1200°F)** | 22-27 | 750-900 MPa | 650-800 MPa | 20-25% | 80-100 J | #### **2. Core Properties After Case Hardening** *Carburize: 900-930°C to 0.8-1.5mm case, Oil Quench, Temper: 150-200°C* | Property | Typical Value Range | Notes | | :--- | :--- | :--- | | **Core Hardness** | 32-40 HRC | Strong core due to C, Mo, and Si | | **Core Tensile Strength** | 900-1100 MPa (130-160 ksi) | - | | **Core Yield Strength** | 750-950 MPa (110-140 ksi) | - | | **Core Elongation** | 12-18% | - | | **Case Hardness** | 58-63 HRC | - | | **Effective Case Depth** | 0.8-1.5 mm (0.030-0.060") | - | | **Fatigue Strength** | 450-550 MPa (65-80 ksi) | Rotating bending, 10⁷ cycles | ### **D. Special Properties** - **Hardenability:** Good to very good; suitable for sections up to 50-75mm (2-3") diameter - **Temper Resistance:** Excellent resistance to softening due to Mo and Si synergy - **Fatigue Strength:** Good bending and torsional fatigue performance - **Impact Toughness:** Maintains good toughness at medium strength levels - **Wear Resistance:** Good in hardened condition; excellent when case-hardened - **High-Temperature Stability:** Better than plain carbon steels up to 400°C (750°F) --- ## **3. International Standards & Specifications** ### **Primary Governing Standards** | Standard/Organization | Designation | Title/Scope | | :--- | :--- | :--- | | **AISI/SAE** | 4028 | Standard grade designation | | **UNS** | G40280 | Unified Numbering System | | **ASTM** | A29/A29M | Standard Specification for Steel Bars, Carbon and Alloy, Hot-Wrought | | **ASTM** | A322 | Standard Specification for Steel Bars, Alloy, Standard Grades | | **SAE** | J404, J412 | Chemical compositions and hardenability | | **AMS** | - | Not commonly specified for aerospace | ### **International Equivalents & Cross-References** | Country/Region | Equivalent Designation | Standard | Notes | | :--- | :--- | :--- | :--- | | **ISO** | **28MnMo6** | ISO 683-11 | Similar medium-carbon steel with Mo | | **European** | **28MnMo6** | EN 10083-3 | Similar properties and applications | | **Germany** | **28MnMo6** | DIN 17210 | Close equivalent, similar Si range | | **United Kingdom** | **- (See Note)** | BS 970 | No direct equivalent; similar to En 111 | | **Japan** | **- (See Note)** | JIS G4102 | No common direct equivalent | | **China** | **30Mo** | GB/T 3077 | Similar molybdenum steel concept | | **India** | **30Mo40** | IS 5517 | Similar medium-carbon Mo steel | | **Hardenability Variant** | **4028H** | SAE J1268 | Available with guaranteed hardenability bands | **Note:** AISI 4028 is primarily a North American grade. The closest international equivalents typically focus on the molybdenum content, with silicon levels varying. For international procurement, specification by chemical composition is recommended. --- ## **4. Product Applications & Industries** ### **Available Product Forms** - **Bar Stock:** Hot-rolled rounds (10-200mm), squares, hexagons, flats - **Forgings:** Open-die and closed-die forgings - **Wire Rod:** For cold heading and forming operations - **Cold-Finished Bars:** Turned, ground, polished for precision applications - **Billets:** For further processing ### **Primary Industry Applications** #### **1. Automotive & Transportation** - **Transmission Components:** Gears, synchronizers, shift forks - **Drivetrain Parts:** Axle shafts, drive shafts, differential components - **Engine Components:** Crankshafts (medium duty), camshafts, connecting rods - **Steering & Suspension:** Steering arms, pitman arms, torsion bars - **Fasteners:** High-strength bolts, studs, and special fasteners #### **2. Agricultural Equipment** - **Tractor Components:** Transmission gears, PTO shafts, final drive parts - **Harvesting Equipment:** Combine gearbox components, drive shafts - **Implement Parts:** Gearboxes, drive trains for tillage equipment - **Drive Components:** Chain sprockets, coupling components #### **3. Industrial Machinery & Equipment** - **Gear Manufacturing:** Medium-duty industrial gears - **Power Transmission:** Shafts, couplings, sprockets - **Material Handling:** Conveyor drive components, hoisting equipment - **Construction Equipment:** Rollers, idlers, track components - **Mining Equipment:** Crusher parts, conveyor components #### **4. General Manufacturing** - **Shafts & Axles:** Various industrial applications - **Fasteners:** Grade 8.8 and similar strength class fasteners - **Tooling:** Jigs, fixtures, wear plates - **Hydraulic Components:** Cylinder rods, piston rods, valve parts - **Machine Tools:** Feed screws, lead screws, spindle components --- ## **5. Heat Treatment Technology** ### **A. Case Hardening Processes** #### **1. Carburizing (Primary Method)** - **Temperature:** 900-930°C (1650-1705°F) - **Atmosphere:** Endothermic gas with enrichment - **Case Depth:** 0.8-1.5 mm typical - **Quenching:** Oil quench from 800-830°C - **Tempering:** 150-200°C for 1-2 hours #### **2. Carbonitriding (Alternative)** - **Temperature:** 815-870°C (1500-1600°F) - **Benefits:** Faster, less distortion, good for thin cases - **Applications:** Fasteners, small components ### **B. Through-Hardening** - **Austenitizing:** 830-850°C (1525-1560°F) - **Quenching:** Oil quench - **Tempering:** Temperature based on required hardness - **Applications:** Components requiring uniform properties ### **C. Special Silicon-Related Considerations** 1. **Decarburization:** Silicon can promote decarburization; protective atmospheres recommended 2. **Scale Formation:** Silicon increases scaling resistance at high temperatures 3. **Hardenability Effect:** Silicon's effect is maximized in combination with molybdenum 4. **Tempering Response:** Enhanced temper resistance allows higher tempering temperatures for toughness ### **D. Recommended Heat Treatment Sequence** 1. **Normalizing:** 870-900°C, air cool (optional, for grain refinement) 2. **Machining:** To final dimensions plus grinding allowance 3. **Carburizing/Through-Hardening:** As required 4. **Quenching:** Oil quench with proper agitation 5. **Tempering:** Immediately after quenching 6. **Finishing:** Grinding, shot peening, etc. --- ## **6. Manufacturing & Fabrication Characteristics** ### **Machinability Assessment** - **Annealed Condition:** 60-65% of B1112 - **Factors Affecting Machinability:** - Silicon content slightly reduces machinability compared to lower-silicon grades - Proper annealing improves machinability - Sulfur-controlled versions available for improved machinability - **Recommended Practices:** - **Turning:** 70-100 m/min with carbide - **Drilling:** 18-28 m/min with HSS - **Milling:** 65-95 m/min with carbide - **Coolant:** Recommended for best results ### **Weldability Characteristics** **Rating: FAIR (with precautions)** #### **Welding Recommendations** 1. **Preheat:** 150-250°C depending on thickness 2. **Interpass Temperature:** 150-200°C 3. **Post-Weld Heat Treatment:** Stress relief at 590-650°C recommended 4. **Filler Metals:** Low-hydrogen electrodes (E7018, E8018) 5. **Processes:** GTAW or SMAW with low-hydrogen electrodes 6. **Considerations:** Silicon can affect weld fluidity and slag characteristics ### **Formability & Hot Working** - **Hot Working Temperature:** 1150-900°C - **Forging:** Good with proper temperature control - **Cold Formability:** Limited; best for simple shapes in annealed condition - **Hot Forming:** Preferred for complex shapes --- ## **7. Quality Assurance & Testing** ### **Standard Testing** - **Chemical Analysis:** Verification of key elements, especially Si and Mo - **Mechanical Testing:** Hardness, tensile properties - **Microstructural Examination:** Grain size, inclusion rating - **Non-Destructive Testing:** As required by specification ### **Special Considerations** - **Silicon Verification:** Important for consistent heat treatment response - **Decarburization Check:** For surfaces subject to final grinding - **Hardenability Testing:** For H-grade variants --- ## **8. Design & Engineering Guidelines** ### **Advantages of AISI 4028** 1. **Enhanced Strength:** Silicon provides solid solution strengthening 2. **Improved Hardenability:** Mo and Si combination offers good through-hardening capability 3. **Good Temper Resistance:** Maintains strength at elevated temperatures 4. **Cost-Effective:** More economical than Ni-Cr alloyed steels 5. **Versatility:** Suitable for case hardening or through-hardening ### **Design Considerations** - **Section Size:** Suitable for sections up to 75mm diameter - **Loading Conditions:** Good for bending and torsional loads - **Temperature Service:** Better than plain carbon steels up to 400°C - **Alternative Materials:** For higher toughness requirements, consider 8620 or 4320 ### **Economic Considerations** - **Material Cost:** Moderate premium over plain carbon steels - **Processing Cost:** Standard heat treatment processes - **Life Cycle Cost:** Good value for performance requirements --- ## **9. Comparative Analysis: 4028 vs. Similar Grades** | Grade | C% | Si% | Mo% | Key Features | Best Applications | | :--- | :--- | :--- | :--- | :--- | :--- | | **1028** | 0.25-0.30 | 0.15-0.35 | - | Plain carbon, economical | Light duty components | | **4028** | 0.25-0.30 | **0.20-0.35** | **0.20-0.30** | **Enhanced hardenability & strength** | **Medium duty, requires better properties** | | **4027** | 0.25-0.30 | 0.15-0.35 | 0.20-0.30 | Similar but standard Si | General medium duty | | **4118** | 0.18-0.23 | 0.15-0.35 | 0.08-0.15 | Cr addition for hardenability | Automotive gears | | **8620** | 0.18-0.23 | 0.15-0.35 | 0.15-0.25 | Ni-Cr-Mo, superior toughness | Critical components | --- ## **10. Technical Summary & Selection Guidelines** ### **Optimal Applications** 1. **Medium-duty gears and shafts** requiring better properties than plain carbon steel 2. **Components requiring both strength and reasonable toughness** 3. **Applications where temper resistance is beneficial** 4. **Cost-sensitive applications needing better than carbon steel performance** ### **Selection Criteria** **Choose AISI 4028 when:** - Enhanced properties over plain carbon steel are needed - Good hardenability is required for section sizes up to 75mm - Temper resistance is advantageous - Cost constraints limit use of Ni-Cr alloyed steels - Silicon's strengthening effect is beneficial **Consider alternatives when:** - Maximum toughness is critical (choose Ni-alloyed grades) - Very high hardenability is needed for large sections - Welding is a primary fabrication method (consider lower carbon grades) - Maximum machinability is required (consider resulfurized grades) ### **Processing Recommendations** 1. **Heat Treatment:** Normalize before machining for stability 2. **Machining:** Use sharp tools with adequate cooling 3. **Heat Treatment Protection:** Use protective atmospheres to minimize decarburization 4. **Quality Verification:** Check critical dimensions after heat treatment --- ## **Market Position & Technical Significance** ### **Technical Significance** AISI 4028 represents an optimized composition where silicon is utilized not just as a deoxidizer, but as a deliberate alloying element to enhance strength and hardenability. The synergy between molybdenum and silicon creates a cost-effective material with properties between plain carbon steels and more expensive nickel-chromium alloys. ### **Market Position** - **Primary Market:** North American industrial and automotive sectors - **Competitive Position:** Between plain carbon and premium alloy steels - **Supply Availability:** Readily available from steel service centers - **Future Relevance:** Continues to be relevant for cost-performance optimized applications --- **AISI 4028** provides a balanced, cost-effective solution for applications requiring better mechanical properties than plain carbon steels can offer, without the expense of nickel or chromium additions. Its deliberate use of silicon as an alloying element, combined with molybdenum, creates a material with enhanced hardenability, strength, and temper resistance. While not suitable for the most demanding applications, AISI 4028 fills an important niche in the spectrum of engineering steels, offering reliable performance for a wide range of medium-duty industrial, automotive, and machinery components where the optimal balance of cost and performance is paramount. -:- For detailed product information, please contact sales. -: AISI 4028 Steel Specification Dimensions Size： Diameter 20-1000 mm Length <4019 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 4028 Steel Properties -:- For detailed product information, please contact sales. -:

Applications of AISI 4028 Steel Flange -:- For detailed product information, please contact sales. -: Chemical Identifiers AISI 4028 Steel Flange -:- For detailed product information, please contact sales. -:

Packing of AISI 4028 Steel Flange -:- 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 490 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