Medium-Silicon Ductile Iron Sheet,Plate, heat-resistant ductile Iron Sheet,Plate

Medium-Silicon Ductile Iron Sheet/Plate, heat-resistant ductile Iron Sheet/Plate Product Information -:- For detailed product information, please contact sales. -: Medium-Silicon Ductile Iron Sheet/Plate, heat-resistant ductile Iron Sheet/Plate Synonyms -:- For detailed product information, please contact sales. -:

Medium-Silicon Ductile Iron, heat-resistant ductile iron Product Information -:- For detailed product information, please contact sales. -: ## **Product Introduction: Medium-Silicon Heat-Resistant Ductile Iron (Ferritic Si-Mo Ductile Iron)** Medium-Silicon Heat-Resistant Ductile Iron, most notably represented by **Silicon-Molybdenum (Si-Mo) ductile iron**, is a high-performance ferritic grade specifically engineered to deliver an exceptional combination of high-temperature strength, oxidation resistance, and thermal fatigue resistance. By alloying with elevated silicon and strategic additions of molybdenum, this material stabilizes a fully ferritic matrix while dramatically improving its performance at elevated temperatures, typically in the range of **600°C to 800°C (1110°F to 1470°F)**. Unlike standard ductile iron, which rapidly loses strength and suffers from growth and scaling above 400°C, Si-Mo ductile iron maintains its structural integrity, making it a preferred material for complex, load-bearing components in demanding thermal environments. This alloy successfully bridges the gap between standard ductile iron and expensive high-nickel austenitic grades, offering a cost-effective solution with superior room and elevated temperature toughness compared to gray iron counterparts. --- ### **1. Chemical Composition** Heat resistance is achieved through a ferrite-stabilizing, solid-solution strengthening approach with silicon, augmented by molybdenum for high-temperature strength. **Typical Composition Range (e.g., Common Si-Mo Grade):** | Element | Content (%) | Primary Function in Heat Resistance | | :--- | :--- | :--- | | **Silicon (Si)** | **3.50 - 4.50** | **Primary alloying element.** Raises the ferrite-to-austenite transformation temperature (A₁ point), stabilizing a fully ferritic matrix up to higher temperatures. This eliminates pearlite decomposition and associated growth. It also promotes a protective SiO₂-rich surface scale. | | **Molybdenum (Mo)** | **0.40 - 1.00** | **Key strengthener.** Provides potent solid solution strengthening and forms stable carbides, significantly improving high-temperature tensile strength, yield strength, and creep resistance without promoting pearlite. | | **Carbon (C)** | 3.00 - 3.80 | Ensures full nodularization for ductility. Higher carbon can improve castability but is balanced against carbide formation. | | **Manganese (Mn)** | **≤ 0.30** | **Kept deliberately low.** High Mn stabilizes pearlite, which is detrimental to long-term growth resistance. Low Mn is critical for stabilizing ferrite. | | **Chromium (Cr)** | ≤ 0.10 (Optional, trace) | Typically avoided or minimized, as it can promote pearlite and harmful chromium carbides, reducing toughness and thermal conductivity. | | **Magnesium (Mg)** | 0.03 - 0.06 | Essential nodularizing element for spheroidal graphite formation. | | **Iron (Fe)** | Balance | Base metal. | **Microstructural Note:** The ideal microstructure is a **fully ferritic matrix** with a uniform distribution of **well-nodularized, spheroidal graphite (Type VI, >80% nodularity)**. The absence of pearlite, carbides (except fine Mo-carbides), and free ferrite in the as-cast condition is crucial and is often achieved through a ferritizing annealing heat treatment. --- ### **2. Physical & Mechanical Properties at Room & Elevated Temperature** This material is characterized by its excellent property retention at high temperatures, stemming from its stable ferritic-nodular structure. | Property | Typical Value / Description | | :--- | :--- | | **Microstructure** | Fully ferritic matrix with spheroidal graphite. | | **Density** | ~7.0 - 7.1 g/cm³ | | **Tensile Strength (Room Temp)** | **450 - 600 MPa (65 - 87 ksi)** | | **Yield Strength (0.2% Offset, Room Temp)** | **350 - 500 MPa (51 - 73 ksi)** | | **Elongation (Room Temp)** | **10 - 20%** – Maintains significant ductility. | | **Hardness (Room Temp)** | **170 - 230 HB** | | **Impact Resistance (Charpy V-Notch)** | **12 - 20 J (9 - 15 ft-lbf)** at room temperature. | | **Maximum Service Temperature** | **Up to 800°C (1470°F)** in air for long-term service. Short-term peaks to 850°C are possible. | | **Growth Resistance** | **Excellent.** Dimensional change after 1000 hours at 700°C is typically <0.1%. | | **Oxidation/Scaling Resistance** | **Very Good.** Forms a protective, adherent silicon-rich oxide scale. Superior to unalloyed ductile iron. | | **Thermal Conductivity** | Good (~30 W/m·K). Lower than low-Si ductile iron but better than austenitic grades. Aids in heat dissipation. | | **Thermal Shock Resistance** | **Excellent.** The combination of good ductility, moderate strength, good conductivity, and the nodular graphite structure provides outstanding resistance to cracking from thermal cycles. | | **Creep & Rupture Strength** | **Very Good.** Mo addition provides excellent resistance to deformation under load at high temperatures. | | **Fatigue Strength** | High, both at room and elevated temperatures. | --- ### **3. Key Product Advantages & Characteristics** * **High Strength & Ductility at Temperature:** Uniquely combines useful tensile/creep strength with good toughness up to 800°C. * **Exceptional Thermal Fatigue Resistance:** The premier choice for components subjected to severe thermal cycling (e.g., exhaust manifolds). * **Stable Microstructure:** Fully ferritic matrix ensures no detrimental phase changes during heating/cooling, preventing growth. * **Good Castability and Machinability:** Easier to cast than high-alloy grades and can be machined with standard tools. * **Cost-Performance Leader:** Offers the best balance of high-temperature performance, room-temperature properties, and cost among heat-resistant ductile irons. --- ### **4. Product Applications** This material is the industry standard for high-integrity, thermally cycled, load-bearing components in automotive and industrial sectors. * **Automotive & Truck:** **Turbocharger housings** and **exhaust manifolds** for gasoline and diesel engines, especially for high-performance and heavy-duty applications. EGR coolers and components. * **Power Generation:** Components for exhaust gas recirculation systems, turbine housings, and heat shields. * **Industrial Furnaces:** Fixtures, jigs, and handling components subject to both load and thermal cycles. * **Hydraulics & Machinery:** High-pressure valve bodies and pumps operating in hot environments. --- ### **5. International Standards** While not as universally codified as some grades, Si-Mo ductile iron is recognized in major automotive and general engineering standards. | Standard | Title / Scope | Common Designations / Notes | | :--- | :--- | :--- | | **ISO 1083** | *Austenitic cast irons – Classification* (General) | Often specified under **ISO 1083/JS/600-10** with the requirement of Si>3.4% and Mo addition, designated as a **special grade**. | | **EN 1563** | *Founding – Spheroidal graphite cast irons* (European) | **EN-GJS-SiMo 4-1** or **EN-GJS-SiMo 5-1** (e.g., GJS-500-14 with SiMo). The material number system allows for specification of Si and Mo ranges. | | **SAE J1887** | *Heat Resistant Ferritic Si-Mo Ductile Iron Castings for Turbocharger Housings* | The key **automotive standard**. Defines grades like **SiMo 4.0-1.0** and **SiMo 5.0-1.0** with strict chemical and mechanical property requirements for turbo applications. | | **ASTM A897/A897M** | *Standard Specification for Austempered Ductile Iron* | While for ADI, its compositional guidelines often overlap. Si-Mo grades are typically specified by proprietary or customer specifications in the US, referencing **SAE J1887**. | | **GB/T 26656** | *Silicon Molybdenum Heat Resistant Spheroidal Graphite Cast Iron* (Chinese) | Directly standardizes grades like **RQTSi4Mo** and **RQTSi5Mo**. | **Specification Note:** For critical applications like turbochargers, the **SAE J1887** standard is predominant. Procurement typically requires specification of the **grade (e.g., SiMo 4.0-1.0)**, mechanical properties at room temperature, and often **high-temperature property validation** (e.g., tensile strength at 700°C). --- ### **Conclusion** Medium-Silicon (Si-Mo) Heat-Resistant Ductile Iron is a metallurgically sophisticated, ferritic-grade material that sets the benchmark for **high-temperature mechanical performance in thermally cycled components**. Its **fully ferritic matrix, stabilized by high silicon and strengthened by molybdenum**, delivers an unparalleled combination of **thermal fatigue resistance, growth resistance, and retained strength/ductility** in the 600-800°C range. As the **material of choice for modern high-performance exhaust manifolds and turbocharger housings**, it demonstrates how alloy design in ductile iron can meet the extreme demands of advanced thermal-mechanical engineering, offering a reliable and cost-optimized alternative to more expensive cast steels or nickel alloys. -:- For detailed product information, please contact sales. -: Medium-Silicon Ductile Iron, heat-resistant ductile iron Specification Dimensions Size： Diameter 20-1000 mm Length <6486 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. -: Medium-Silicon Ductile Iron, heat-resistant ductile iron Properties -:- For detailed product information, please contact sales. -:

Applications of Medium-Silicon Ductile Iron Sheet,Plate, heat-resistant ductile Iron Sheet,Plate -:- For detailed product information, please contact sales. -: Chemical Identifiers Medium-Silicon Ductile Iron Sheet,Plate, heat-resistant ductile Iron Sheet,Plate -:- For detailed product information, please contact sales. -:

Packing of Medium-Silicon Ductile Iron Sheet/Plate, heat-resistant ductile Iron Sheet/Plate -:- 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 Sheet/Plate 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 2957 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