High Silicon Ductile Iron Rod/Bar at RT 4Si-1.0Mo nominal alloy content

High Silicon Ductile Iron Rod at RT 4Si-1.0Mo nominal alloy content Product Information -:- For detailed product information, please contact sales. -: High Silicon Ductile Iron Rod at RT 4Si-1.0Mo nominal alloy content Synonyms -:- For detailed product information, please contact sales. -:

High Silicon Ductile Iron at RT 4Si-1.0Mo nominal alloy content Product Information -:- For detailed product information, please contact sales. -: ### **Product Technical Data Sheet: High Silicon Ductile Iron – RT Series (Nominal 4% Si - 1.0% Mo Alloy)** --- #### **1. Product Overview** **High Silicon Ductile Iron (HSDI) with nominal 4% Silicon and 1.0% Molybdenum (4Si-1.0Mo)** is a **premium, high-performance ferritic ductile iron** engineered for the most severe high-temperature service environments. This alloy represents the upper tier of the RT-series development, where the synergistic combination of **maximized solid-solution strengthening from silicon** and **potent precipitation/carbide strengthening from molybdenum** creates a material with **exceptional elevated-temperature strength, outstanding creep resistance, and excellent long-term microstructural stability**. It is designed to operate reliably under high static and cyclic thermal stresses where standard and lower-alloyed ductile irons would fail, offering a cost-effective alternative to high-nickel austenitic cast irons and some stainless steels in specific temperature ranges. --- #### **2. Governing Standards & Specifications** This is a high-end engineering alloy, typically specified under proprietary or rigorous customer-driven standards. * **Primary References:** * **Proprietary/High-Performance Alloys:** Often designated under codes like **RT-4Mo1** or classified within commercial **SiMo ductile iron families** (e.g., SiMo 4.0-1.0, SiMo 4.5-1.0). * **Industry Framework Standards:** Serves as a high-performance variant within the context of: * **ISO 1083 / EN 1563** for alloyed spheroidal graphite cast irons. * **Customer-Specific Material Specifications** are the norm for defining exact properties and acceptance criteria. * **Key Testing Standards:** ASTM E8/E21 (Tensile), E139 (Creep), E292 (Stress Rupture), G54 (Oxidation), G28 (Corrosion). --- #### **3. Typical Chemical Composition** The composition is optimized for peak high-temperature performance, with stringent control over detrimental elements. | Element | Target Range (wt.%) | Critical Role & Rationale | | :--- | :--- | :--- | | **Carbon (C)** | **2.7 - 3.2** | **Significantly lowered.** Essential to counteract the powerful graphitizing effect of high Si and avoid excessive carbon equivalent, ensuring sound castings and preventing graphite degeneration. | | **Silicon (Si)** | **3.8 - 4.2 (Nominal 4.0)** | **Primary Alloy.** Provides **intense solid solution strengthening** of ferrite, dramatically raises the Ac1 transformation temperature (>900°C), and forms a dense, self-healing SiO₂ layer for **superior oxidation resistance** up to 950°C. | | **Molybdenum (Mo)** | **0.9 - 1.1 (Nominal 1.0)** | **Critical High-Temperature Enhancer.** Provides **solid solution strengthening** and promotes the formation of fine, thermally stable Mo-rich carbides (e.g., M₆C, M₂₃C₆). This **significantly improves high-temperature tensile and yield strength, dramatically enhances creep and stress-rupture life, and suppresses pearlite formation** during processing. | | **Manganese (Mn)** | **≤ 0.15** | **Extremely low.** Imperative to prevent the formation of complex (Mn,Mo,Si)-based brittle intermetallic phases at cell boundaries, which are catastrophic for ductility and toughness. | | **Magnesium (Mg)** | 0.03 - 0.06 | Ensures high nodularity in the challenging high-alloy melt. | | **Cerium (Ce)/Rare Earths** | Typically used | Critical for achieving and maintaining nodularity, and for neutralizing trace elements like Pb, Sb, Bi. | | **Phosphorus (P)** | **≤ 0.025** | **Ultra-low.** Phosphorus embrittlement is severely exacerbated in high-Si, high-Mo alloys; control is non-negotiable. | | **Nickel (Ni)** | ≤ 0.50 | Incidental only. | --- #### **4. Physical & Mechanical Properties** The 1.0% Mo addition provides a step-change in high-temperature mechanical performance. | Property | Typical Value (Room Temp) | Elevated Temperature Performance (e.g., 700-800°C / 1292-1472°F) | | :--- | :--- | :--- | | **Tensile Strength (UTS)** | **650 - 800 MPa (94 - 116 ksi)** | **Retains ~55-70% of RT UTS** at 700°C. Outstanding strength retention. | | **Yield Strength (0.2% YS)** | **500 - 650 MPa (73 - 94 ksi)** | **Retains ~60-75% of RT YS** at 700°C. Exceptional resistance to deformation under load at temperature. | | **Elongation** | **5 - 12%** | RT ductility is moderate; it is a strength- and creep-dominated alloy. | | **Hardness (HBW)** | 240 - 300 HBW | High hardness reflects the significant matrix strengthening. | | **Modulus of Elasticity** | ~150 - 160 GPa | Slightly reduced due to high alloy content. | | **Creep & Stress Rupture** | **Excellent.** The 1.0% Mo addition provides a **marked improvement in rupture life and lowers minimum creep rate** compared to the 0.5% Mo variant, especially above 700°C. Capable of sustained load at temperatures up to ~800°C. | | **Oxidation Resistance** | **Outstanding.** Protective SiO₂ scale offers excellent resistance to scaling and oxidation in air up to **900-950°C (1652-1742°F)**. | | **Thermal Conductivity** | **~26-30 W/m·K** | Reduced due to high alloying, a consideration for thermal shock applications. | | **Thermal Fatigue Resistance** | **Excellent.** High strength and good ductility provide excellent resistance to crack initiation under severe thermal cycling. | | **Microstructural Stability** | **Exceptional.** The ferritic matrix with Mo-carbides is highly stable against phase transformations and carbide coarsening during long-term high-temperature exposure. | | **Microstructure** | **100% Ferritic Matrix** with **Spheroidal Graphite** and a fine, uniform dispersion of **Mo-rich carbides**. Free of pearlite. | --- #### **5. Product Applications** This alloy is specified for the most demanding high-temperature, high-stress applications across advanced industries. * **Turbocharging & Exhaust Manifolds:** For extreme-performance and large-bore engines, where gas temperatures exceed 850°C and pressures are high. * **Exhaust Gas Recirculation (EGR) Systems:** **Coolers and valves** in advanced emission control systems handling very hot, corrosive gases. * **Industrial Furnace & Heat Treatment:** **Radiant tubes, charge carriers, fan impellers, and fixture components** in carburizing, annealing, and brazing furnaces operating at 850-1000°C. * **Power Generation & Waste Heat Recovery:** **Turbine housings, valve bodies, and components** in advanced combined-cycle and waste-heat-boiler systems. * **Chemical & Petrochemical:** **Reform furnace tubes, pyrolysis tube fittings, and catalyst support grids** where creep strength and corrosion resistance are critical. --- #### **6. Fabrication & Processing Notes** * **Melting & Casting:** Requires advanced foundry practices. High Mo content increases the tendency for micro-segregation and carbide formation; controlled cooling and section size design are critical. * **Heat Treatment:** Almost always used in the **as-cast and subcritically annealed** condition. The high Ac1 temperature makes conventional hardening impractical. Annealing is used to temper any as-cast carbides and ensure full ferritization. * **Machinability:** **Very Difficult.** Highly abrasive and strong. Requires premium carbide or ceramic tooling, low speeds, high rigidity, and effective cooling. * **Weldability:** **Not Recommended for Service.** Extremely prone to cold cracking and HAZ embrittlement. Fabrication is by casting only; repair welding is highly specialized and rarely successful. --- #### **7. Ordering Information** **Specify:** **"High Silicon-Molybdenum Ductile Iron Castings, 4Si-1.0Mo Alloy (e.g., SiMo 4.0-1.0), Heat Treated per [Agreed Specification]."** **Critical Details to Provide:** * **Precise Compositional Limits**, especially for Si, Mo, C, P, Mn. * **Mechanical Property Guarantees** at room temperature **and** at specified high temperatures (e.g., 700°C, 800°C). * **Application-Specific Performance Criteria** (e.g., max service temperature & pressure, required creep rupture life at a given stress/temperature, oxidation weight gain limit). * **Certification Requirements:** Full traceability with chemical analysis, RT/HT mechanical tests, microstructure report (graphite nodularity, matrix, carbide distribution). * **Validation Testing:** **Stress-rupture testing**, **long-term oxidation testing**, and **component-specific thermal cycling validation** are commonly required. **The 4Si-1.0Mo High Silicon Ductile Iron alloy represents the pinnacle of ferritic ductile iron technology for high-temperature structural applications, delivering an unmatched balance of extreme temperature strength, creep resistance, and environmental durability.** -:- For detailed product information, please contact sales. -: High Silicon Ductile Iron at RT 4Si-1.0Mo nominal alloy content Specification Dimensions Size： Diameter 20-1000 mm Length <6545 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. -: High Silicon Ductile Iron at RT 4Si-1.0Mo nominal alloy content Properties -:- For detailed product information, please contact sales. -:

Applications of High Silicon Ductile Iron Rod at RT 4Si-1.0Mo nominal alloy content -:- For detailed product information, please contact sales. -: Chemical Identifiers High Silicon Ductile Iron Rod at RT 4Si-1.0Mo nominal alloy content -:- For detailed product information, please contact sales. -:

Packing of High Silicon Ductile Iron Rod at RT 4Si-1.0Mo nominal alloy content -:- 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 Rod 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 3016 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