High-Chromium Iron Tube,Pipe, heat-resistant gray Iron Tube,Pipe

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

High-Chromium Iron, heat-resistant gray iron Product Information -:- For detailed product information, please contact sales. -: ## **Product Introduction: High-Chromium Heat-Resistant Gray Iron** High-Chromium Heat-Resistant Gray Iron is a premium, alloyed cast iron engineered to withstand severe thermal environments, offering exceptional performance at service temperatures **exceeding 850°C (1560°F) and up to 1150°C (2100°F)**. Its defining characteristic is a high chromium content, which fundamentally transforms its microstructure and surface chemistry. Chromium promotes the formation of a stable, iron-chromium carbides (e.g., (Fe,Cr)₇C₃, (Fe,Cr)₂₃C₆) and, most critically, enables the development of a dense, tightly adherent chromium oxide (Cr₂O₃) scale on the surface. This scale acts as a highly effective barrier against oxidation, carburization, and sulfur attack, making this material the cast iron of choice for the most demanding high-temperature applications. This alloy represents the pinnacle of heat resistance within the gray iron family, bridging the gap between lower-alloy irons and fully austenitic stainless steels or nickel-based alloys. --- ### **1. Chemical Composition** Heat and corrosion resistance at extreme temperatures are achieved through high chromium content, often supplemented with silicon and nickel. The composition is tightly controlled to balance hardness, castability, and thermal stability. **Typical Composition Ranges for Common Grades:** | Element | Standard Grade | High-Performance Grade | Primary Function in Heat Resistance | | :--- | :--- | :--- | :--- | | **Chromium (Cr)** | **15.0 - 20.0%** | **25.0 - 35.0%** | **Core alloying element.** Forms protective **Cr₂O₃ scale**; creates hard, thermally stable chromium carbides; raises the A₁ transformation temperature; provides excellent resistance to oxidation, sulfidation, and carburization. | | **Carbon (C)** | 1.50 - 2.20% | 1.20 - 2.00% | Combines with Cr to form stable carbides, providing high-temperature strength and wear resistance. Lower C improves ductility and weldability. | | **Silicon (Si)** | 1.00 - 3.00% | 1.50 - 3.00% | Synergizes with Cr to improve oxidation resistance, stabilizes ferrite, and improves fluidity. | | **Nickel (Ni)** | 0 - 2.0% | 0 - 15.0% | Added in some grades to improve toughness, thermal shock resistance, and to stabilize austenite in the highest-temperature grades. | | **Manganese (Mn)** | 0.30 - 1.00% | 0.30 - 1.00% | General deoxidizer and mild solid solution strengthener. | | **Molybdenum (Mo)** | 0 - 1.5% | 0 - 2.0% | Enhances high-temperature strength and creep resistance. | | **Iron (Fe)** | Balance | Balance | Base metal. | **Microstructural Note:** The microstructure is complex, typically consisting of a **martensitic, ferritic, or austenitic matrix** (depending on Cr/Ni ratio) with a network of **primary and eutectic chromium carbides**, and graphite flakes. The high carbide content makes it inherently hard and abrasion-resistant. --- ### **2. Physical & Mechanical Properties at Room & Elevated Temperature** These materials are optimized for hot service, often at the expense of room-temperature machinability and ductility. | Property | Typical Value / Description | | :--- | :--- | | **Microstructure** | Carbide-rich matrix (martensitic/ferritic) with graphite flakes and complex chromium carbides (M₇C₃, M₂₃C₆). | | **Density** | ~7.2 - 7.5 g/cm³ | | **Tensile Strength (Room Temp)** | **300 - 550 MPa (44 - 80 ksi)** – Can be significantly higher than standard gray irons due to carbide strengthening. | | **Compressive Strength** | **Very High** – Excellent for load-bearing applications at temperature. | | **Hardness (Room Temp)** | **300 - 600 HB** – Very hard and wear-resistant, but challenging to machine. | | **Elongation** | **Negligible (<0.5%)** – Brittle at room temperature. | | **Maximum Service Temperature** | **900°C - 1150°C (1650°F - 2100°F)**, depending on Cr content and atmosphere. Continuously oxidizing: up to 1150°C. Cyclic conditions: lower. | | **Oxidation/Scaling Resistance** | **Outstanding.** The Cr₂O₃ scale is highly protective in oxidizing, carburizing, and sulfur-containing atmospheres. | | **Growth Resistance** | **Excellent.** The stable carbides and high A₁ temperature prevent pearlite-related growth. | | **Thermal Conductivity** | Moderate to Low – Lower than standard gray iron due to alloying. | | **Thermal Shock Resistance** | **Fair to Good.** High strength helps, but lower conductivity and brittleness can be limiting. Nickel additions improve this property. | | **Abrasion/Wear Resistance** | **Exceptional** at all temperatures, due to the hard chromium carbides. | --- ### **3. Key Product Advantages & Characteristics** * **Unmatched Heat & Oxidation Resistance:** Capable of continuous service in air where most other cast irons fail. Resists scaling, growth, and deformation. * **Excellent Environmental Resistance:** Superior performance in carburizing, sulfidizing, and chlorine-containing atmospheres compared to nickel-based alloys in certain ranges. * **Outstanding Abrasion & Wear Resistance:** The high volume of hard carbides provides exceptional resistance to mechanical wear, even at high temperatures. * **High Hot Strength & Creep Resistance:** Maintains load-bearing capability under stress at extreme temperatures. * **Cost-Effective for Specific Duties:** Often more economical than heat-resistant steels or superalloys for applications where its unique combination of wear and heat resistance is required. --- ### **4. Product Applications** This material is specified for the most severe high-temperature service where oxidation, wear, and stability are paramount. * **Furnace & Heat Treatment:** Radiant tubes, burner nozzles, recuperator tubes, furnace trays, skid rails, rolls for reheating furnaces. * **Cement, Lime & Ceramics Industry:** Kiln burners, cooler grates, cyclone liners, nozzle blocks, sintering pallets. * **Power Generation & Waste Incineration:** Grate bars for waste-to-energy plants, ash conveyor parts, boiler components exposed to high erosion/corrosion. * **Chemical & Petrochemical:** Reformers, pyrolysis tubes, and fixtures for high-temperature chemical processes. * **Glass Manufacturing:** Molds, plungers, and orifice rings for handling molten glass. --- ### **5. International Standards** High-chromium heat-resistant cast irons are covered by specialized standards focused on their high-temperature performance. | Standard | Title / Scope | Common Designations / Notes | | :--- | :--- | :--- | | **ASTM A532/A532M** | *Standard Specification for Abrasion-Resistant Cast Irons* | **Class III Type A (15% Cr, 3% Mo)** and other high-Cr white irons. While focused on abrasion, these are often used for combined heat/wear service. | | **JIS G5151** | *Heat resistant castings for high-temperature service* (Japanese) | **SCH 1, SCH 2, SCH 3, etc.** SCH grades (e.g., SCH 13: ~30% Cr) specifically denote high-Cr heat-resistant cast steels and irons. | | **DIN EN 10295** | *Heat-resistant cast steels and cast alloys* (European) | **G-X 40CrSi 27, G-X 300CrMo 15 3** – Material numbers define specific high-Cr, heat-resistant compositions. | | **GB/T 8492** | *Heat resistant cast steels and alloys* (Chinese) | **RTCr16, RTCr20, RTCr28** – The "RT" series explicitly defines high-chromium heat-resistant cast irons. | | **ISO 11973** | *Heat-resistant castings for general applications* | Provides general guidelines and classification for heat-resistant castings, including high-chromium types. | **Specification Note:** Due to the specialized nature of these alloys, procurement typically requires specifying a **detailed chemical composition** and the relevant **performance standards (e.g., oxidation resistance at 1000°C for 500 hours)**. The distinction between "high-chromium cast iron" and "heat-resistant cast steel" can blur at higher chromium levels. --- ### **Conclusion** High-Chromium Heat-Resistant Gray Iron is a specialized, high-performance material designed for survival in extreme thermal and abrasive environments. Its efficacy is derived from a **chromium-rich, carbide-strengthened microstructure** and the formation of a **self-regenerating chromium oxide protective scale**. While characterized by high hardness and limited room-temperature ductility, its value is unparalleled in applications demanding **long-term stability under load at temperatures above 900°C**, particularly where oxidation, carburization, or wear are concurrent challenges. It remains an essential engineering material for aggressive industrial thermal processes. -:- For detailed product information, please contact sales. -: High-Chromium Iron, heat-resistant gray iron Specification Dimensions Size： Diameter 20-1000 mm Length <6482 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-Chromium Iron, heat-resistant gray iron Properties -:- For detailed product information, please contact sales. -:

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

Packing of High-Chromium 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 2953 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