Medium-Silicon Iron Tube,Pipe, heat-resistant gray Iron Tube,Pipe

Medium-Silicon Iron Tube, heat-resistant gray Iron Tube Product Information -:- For detailed product information, please contact sales. -: Medium-Silicon Iron Tube, heat-resistant gray Iron Tube Synonyms -:- For detailed product information, please contact sales. -:

Medium-Silicon Iron, heat-resistant gray iron Product Information -:- For detailed product information, please contact sales. -: ## **Product Introduction: Medium-Silicon Heat-Resistant Gray Iron** Medium-Silicon Heat-Resistant Gray Iron is a specialized class of cast iron engineered to maintain structural integrity and resist degradation at elevated temperatures, typically up to **650°C - 750°C (1200°F - 1380°F)**. Its defining characteristic is a controlled, elevated silicon content, which promotes the formation of a protective, adherent oxide layer and stabilizes the ferritic matrix. This significantly reduces the two primary failure modes of standard gray iron at high temperatures: **oxidation (scaling)** and **growth** (permanent, irreversible dimensional increase due to phase transformation and internal oxidation). This material offers an excellent balance of performance, castability, and cost-effectiveness for components operating in hot, oxidizing, and cyclic thermal environments where standard grades of iron would rapidly degrade. --- ### **1. Chemical Composition** Heat resistance is primarily achieved through alloying with silicon, while other elements are carefully controlled to optimize performance. **Typical Composition Range:** | Element | Content (%) | Primary Function in Heat Resistance | | :--- | :--- | :--- | | **Silicon (Si)** | **3.50 - 5.50** | **Key alloying element.** Promotes a stable, fully ferritic matrix, increases the transformation temperature (A₁ point), and fosters the formation of a dense, self-healing SiO₂-rich oxide scale that protects against further oxidation and growth. | | **Carbon (C)** | 2.40 - 2.90 | Lower than standard gray iron to improve stability. Combined carbon is minimized to prevent pearlite decomposition at temperature. | | **Manganese (Mn)** | 0.30 - 0.80 | Typically kept low to avoid stabilizing pearlite, which is detrimental to long-term growth resistance. | | **Chromium (Cr)** | 0.30 - 0.80 (Optional) | Often added in small amounts to further enhance oxidation resistance and increase scaling temperature. | | **Phosphorus (P)** | ≤ 0.30 | Controlled to maintain adequate toughness and minimize low-melting point eutectics. | | **Sulfur (S)** | ≤ 0.12 | Controlled to ensure sound castings. | | **Iron (Fe)** | Balance | Base metal. | **Microstructural Note:** The goal is a **fully ferritic matrix** with a uniform distribution of **Type A flake graphite**. This structure provides the best combination of thermal conductivity, growth resistance, and resistance to thermal shock. --- ### **2. Physical & Mechanical Properties at Room & Elevated Temperature** The properties are tailored for stability under heat rather than for high room-temperature strength. | Property | Typical Value / Description | | :--- | :--- | | **Microstructure** | **Ferritic matrix with flake graphite.** Essential for heat resistance. | | **Density** | ~7.0 - 7.1 g/cm³ | | **Tensile Strength (Room Temp)** | **150 - 220 MPa (22 - 32 ksi)** – Lower than standard gray irons due to the ferritic structure. | | **Hardness (Room Temp)** | **160 - 220 HB** | | **Elongation** | Negligible (<1%). It remains a brittle material at room temperature. | | **Maximum Service Temperature** | **650°C - 750°C (1200°F - 1380°F)**, depending on Si/Cr content and oxidizing conditions. | | **Growth Resistance** | **Excellent.** Dimensional change after prolonged exposure (e.g., 1000 hours at 700°C) is typically <0.2%. | | **Oxidation/Scaling Resistance** | **Very Good.** Forms a protective, adherent scale. Scaling rates are significantly lower than for unalloyed gray iron. | | **Thermal Conductivity** | Good, though slightly lower than low-silicon gray iron. Aids in distributing thermal stress. | | **Thermal Shock Resistance** | Good to very good, due to good conductivity, moderate strength, and the stress-relieving effect of the graphite flakes. | | **Machinability** | Fair to Good. The ferritic structure is soft but can be abrasive due to hard silicon oxide inclusions. | --- ### **3. Key Product Advantages & Characteristics** * **Excellent Growth Resistance:** The ferritic structure is stable and does not undergo the damaging pearlite-to-austenite transformation upon reheating. * **Good Oxidation Resistance:** The high silicon content promotes a protective, self-limiting oxide layer. * **Good Thermal Shock Resistance:** The combination of thermal conductivity and graphite flake structure helps absorb thermal stresses. * **Retained Strength at Temperature:** Maintains a higher percentage of its room-temperature strength at elevated temperatures compared to unalloyed gray iron. * **Cost-Effective:** More economical than high-nickel (Ni-Resist) or high-chromium heat-resistant alloys for many intermediate temperature applications. --- ### **4. Product Applications** This material is specified for components subjected to continuous or cyclic heating in oxidizing atmospheres. * **Furnace & Heat Treatment Equipment:** Furnace grates, burner nozzles, retorts, radiant tubes, trays, fixturing, and support structures. * **Power Generation & Boilers:** Stoker parts, ash-handling components, heat exchanger parts for exhaust gas. * **Internal Combustion Engines:** Exhaust manifolds, turbocharger housings (for certain diesel applications). * **Chemical Processing:** Parts for reactors and kilns operating at moderate temperatures. * **Glass Manufacturing:** Molds and handling tools for hot glass. --- ### **5. International Standards** Several international standards define heat-resistant cast irons, often categorizing them by silicon content. | Standard | Title / Scope | Common Designations / Notes | | :--- | :--- | :--- | | **ASTM A319/A319M** | *Standard Specification for Gray Iron Castings for Elevated Temperatures for Non-Pressure Containing Parts* | **Class I, II, III.** This is the primary standard. Medium-Si irons typically fall under **Class II (up to 650°C/1200°F)**. Does not prescribe specific compositions but defines property requirements at temperature. | | **ISO 185** | *Grey cast irons — Classification* | While a general standard, its **Grade 150** to **Grade 250** can be used as a base, with Si content specified for heat resistance. | | **JIS G5501** | *Grey iron castings* (Japanese) | **FC200, FC250** with elevated Si specified. Often referenced with additional heat-resistant requirements. | | **GB/T 9437** | *Heat resistant iron castings* (Chinese) | **HTRSi4, HTRSi5** designations explicitly define medium-silicon heat-resistant gray irons (e.g., RTSi-4.0 for ~4% Si). | | **DIN 1691** | *Grey cast iron* (German, withdrawn but referenced) | **GG-20, GG-25** with elevated Si. Often replaced by material-specific data sheets. | **Specification Note:** When ordering, it is most precise to specify both a **material standard (e.g., ASTM A319 Class II)** and the required **chemical composition range (especially Si%)** to ensure the correct metallurgy for the intended service temperature. --- ### **Conclusion** Medium-Silicon Heat-Resistant Gray Iron is a purpose-driven material that provides a reliable and economical solution for a wide range of high-temperature applications. Its effectiveness stems from a **fully ferritic matrix stabilized by elevated silicon**, which combats the twin threats of **growth and oxidation**. While not as strong at room temperature as pearlitic gray irons, its true value is realized in prolonged service at elevated temperatures, where it outperforms standard grades and offers a practical alternative to more expensive high-alloy cast materials. For components like furnace hardware and exhaust manifolds, it remains a staple material in thermal engineering. -:- For detailed product information, please contact sales. -: Medium-Silicon Iron, heat-resistant gray iron Specification Dimensions Size： Diameter 20-1000 mm Length <6481 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 Iron, heat-resistant gray iron Properties -:- For detailed product information, please contact sales. -:

Applications of Medium-Silicon Iron Tube, heat-resistant gray Iron Tube -:- For detailed product information, please contact sales. -: Chemical Identifiers Medium-Silicon Iron Tube, heat-resistant gray Iron Tube -:- For detailed product information, please contact sales. -:

Packing of Medium-Silicon Iron Tube, heat-resistant gray Iron Tube -:- 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 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 2952 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