Nickel-Chromium-silicon Iron Sheet,Plate, heat-resistant gray Iron Sheet,Plate

Nickel-Chromium-silicon Iron Sheet/Plate, heat-resistant gray Iron Sheet/Plate Product Information -:- For detailed product information, please contact sales. -: Nickel-Chromium-silicon Iron Sheet/Plate, heat-resistant gray Iron Sheet/Plate Synonyms -:- For detailed product information, please contact sales. -:

Nickel-Chromium-silicon Iron, heat-resistant gray iron Product Information -:- For detailed product information, please contact sales. -: ## **Product Introduction: Nickel-Chromium-Silicon (Ni-Cr-Si) Heat-Resistant Gray Iron** Nickel-Chromium-Silicon (Ni-Cr-Si) Heat-Resistant Gray Iron represents a highly optimized class of austenitic cast iron, specifically engineered for superior performance in the most demanding high-temperature and thermal cycling environments. By strategically combining nickel for matrix stabilization, chromium for oxidation resistance, and elevated silicon for scaling protection and growth inhibition, this alloy delivers an exceptional balance of properties unmatched by single-element alloyed irons. It is designed for continuous service in oxidizing, reducing, and sulfidizing atmospheres at temperatures ranging from **700°C to 1000°C (1290°F to 1830°F)**, where resistance to thermal fatigue, distortion, and metal wastage is critical. This material is often considered the pinnacle of conventional heat-resistant gray iron technology, offering the stability of high-nickel irons with the enhanced surface protection of high-chromium and high-silicon chemistries. --- ### **1. Chemical Composition** The synergistic effect of Ni, Cr, and Si creates a robust, self-protecting material. The composition is precisely balanced to avoid brittle phases and ensure a fully austenitic, graphite-containing structure. **Typical Composition Range for High-Performance Grades:** | Element | Content (%) | Primary Function in Heat Resistance | | :--- | :--- | :--- | | **Nickel (Ni)** | **18.0 - 30.0** | **Austenite Stabilizer:** Ensures a fully austenitic matrix from room temperature to service conditions, eliminating ferritic-pearlitic phase transformations that cause growth and distortion. Provides inherent toughness and thermal fatigue resistance. | | **Chromium (Cr)** | **2.5 - 5.0** | **Oxidation & Corrosion Resistor:** Forms a continuous, adherent, and self-regenerating chromium oxide (Cr₂O₃) layer within the scale, providing a primary barrier against oxidation, carburization, and sulfidation. Enhances high-temperature strength. | | **Silicon (Si)** | **4.5 - 6.5** | **Scaling & Growth Inhibitor:** Promotes the formation of a dense, silicate-based oxide scale (Fe₂SiO₄, etc.) that further impedes oxygen diffusion. Dramatically raises the temperature at which rapid scaling occurs and stabilizes the matrix against growth. | | **Carbon (C)** | 2.0 - 2.8 | Controlled to ensure sufficient graphite formation for thermal shock resistance and machinability, while maintaining alloy stability and minimizing massive carbides. | | **Manganese (Mn)** | 0.5 - 1.5 | Supports austenite stability and neutralizes sulfur. | | **Molybdenum (Mo)** | 0 - 1.0 (Optional) | Added in some grades to increase high-temperature strength and creep resistance. | | **Iron (Fe)** | Balance | Base metal. | **Microstructural Note:** The target microstructure is a **fully austenitic matrix** with a uniform, interdendritic distribution of **fine, Type A flake graphite** and a controlled dispersion of **complex (Ni, Cr, Fe) carbides**. The absence of ferrite/pearlite is mandatory for optimal performance. --- ### **2. Physical & Mechanical Properties at Room & Elevated Temperature** This alloy is characterized by its stability, retaining useful mechanical properties and surface integrity under prolonged heat exposure. | Property | Typical Value / Description | | :--- | :--- | | **Microstructure** | Austenitic matrix with fine flake graphite and minor alloy carbides. | | **Density** | ~7.1 - 7.3 g/cm³ | | **Tensile Strength (Room Temp)** | **200 - 340 MPa (29 - 49 ksi)** | | **Yield Strength (0.2% Offset)** | **170 - 280 MPa (25 - 41 ksi)** | | **Elongation** | 1 - 4% | | **Hardness (Room Temp)** | **170 - 240 HB** | | **Maximum Service Temperature** | **Up to 1000°C (1830°F)** in continuous oxidizing service, depending on exact composition. Excellent for cyclic service up to ~950°C. | | **Growth Resistance** | **Exceptional.** Typically exhibits growth of less than 0.1% after 1000 hours at 900°C, due to the invariant austenitic structure. | | **Oxidation/Scaling Resistance** | **Outstanding.** The synergistic Si-Cr oxide scale offers superior protection compared to alloys with only one of these elements. Very low scaling rates up to the maximum service temperature. | | **Thermal Conductivity** | Moderate (~13-16 W/m·K). Adequate for managing thermal stresses. | | **Thermal Shock Resistance** | **Excellent.** The combination of austenitic ductility, moderate strength, and graphite flakes provides exceptional resistance to cracking from rapid temperature changes. | | **Creep & Rupture Strength** | Good. Significantly better than standard or medium-silicon gray irons at temperatures above 750°C. | | **Resistance to Attack** | Excellent resistance to sealing (welding to furnace parts) and atmosphere penetration. | | **Machinability** | Fair to Good. Softer than high-chromium irons but can be abrasive due to hard oxide scale formation during casting. | --- ### **3. Key Product Advantages & Characteristics** * **Synergistic Oxidation Resistance:** The combined effect of Cr and Si creates a multi-layered, highly protective oxide scale more effective than scales formed by either element alone. * **Ultra-High Growth Stability:** The nickel-stabilized austenite provides near-zero growth, ensuring dimensional accuracy of fixtures and components over thousands of heating cycles. * **Superior Thermal Fatigue Life:** Excellent for applications involving repeated heating and cooling, such as furnace charge tools and cyclic processing equipment. * **Broad Atmosphere Capability:** Performs well not only in oxidizing air but also in environments with moderate carburizing, sulfidizing, or reducing potential. * **Good Castability and Fabricability:** Can be cast into complex shapes and is generally weldable with correct procedures and matching electrodes. --- ### **4. Product Applications** This premium material is specified for critical, high-value components where failure is not an option due to thermal distortion or excessive scaling. * **Heat Treatment & Sintering Furnaces:** High-precision furnace trays, grids, baskets, fixtureing, roller rails, and fan components for carburizing, nitriding, and sintering. * **Forging & Reheat Furnaces:** Skid rails, support pins, and walking beam components subject to heavy loads and thermal shock. * **Petrochemical & Reforming:** Tube hangers, radiant tube supports, and internals for steam methane reformers and ethylene crackers. * **Glass & Ceramic Manufacturing:** Molds, rolls, and conveyor parts in direct contact with hot glass or ceramic ware. * **Power Generation:** Advanced exhaust manifolds, turbocharger housings, and components in waste heat recovery systems. --- ### **5. International Standards** Ni-Cr-Si heat-resistant irons are typically covered under austenitic cast iron standards, with specific grades defined by their chemical ranges. | Standard | Title / Scope | Common Designations / Notes | | :--- | :--- | :--- | | **ASTM A436** | *Standard Specification for Austenitic Gray Iron Castings* | **Type 4 (D-5S) & Type 5 (D-5S)** are the most relevant, as they specify high Si and Cr. Exact Ni-Cr-Si ratios are achieved within the specified ranges. | | **ISO 2892** | *Austenitic cast irons* | Designations like **JLW/HR/A Ni20Si5Cr3** explicitly indicate a heat-resistant (HR) grade with target chemistry (e.g., 20% Ni, 5% Si, 3% Cr). | | **EN 13835** | *Founding - Austenitic cast irons* (European) | **EN-GJLA-XNiSiCr20-5-3** or similar. The material number directly codes the nominal Ni, Si, and Cr content. | | **JIS G5510** | *Austenitic cast irons* (Japanese) | **FCA-Ni20Cr3Si5** or equivalent manufacturer-specific grades. | | **GB/T 27748** | *Heat resistant austenitic cast iron* (Chinese) | **NTK Si5Cr3** series, specifying the high-silicon, moderate-chromium chemistry under the austenitic class. | **Specification Note:** Due to the critical nature of the triple alloying, procurement often requires **detailed chemical analysis certification** against agreed-upon ranges (e.g., Ni 22-26%, Cr 3.0-3.8%, Si 5.0-5.8%) rather than just a generic type number, to ensure the optimal synergistic effect is achieved. --- ### **Conclusion** Nickel-Chromium-Silicon Heat-Resistant Gray Iron is a sophisticated engineering material where metallurgical design directly targets the simultaneous defeat of oxidation, growth, and thermal fatigue. Its **triple-alloyed (Ni-Cr-Si) chemistry** creates a **stable austenitic matrix** and a **highly protective, complex oxide scale**, delivering unmatched durability in the **700-1000°C range**. While it commands a premium price, its extended service life, reliability in precision fixtures, and reduced downtime for maintenance make it the economically and technically optimal choice for the most severe and critical high-temperature applications in advanced thermal processing industries. -:- For detailed product information, please contact sales. -: Nickel-Chromium-silicon Iron, heat-resistant gray iron Specification Dimensions Size： Diameter 20-1000 mm Length <6484 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. -: Nickel-Chromium-silicon Iron, heat-resistant gray iron Properties -:- For detailed product information, please contact sales. -:

Applications of Nickel-Chromium-silicon Iron Sheet,Plate, heat-resistant gray Iron Sheet,Plate -:- For detailed product information, please contact sales. -: Chemical Identifiers Nickel-Chromium-silicon Iron Sheet,Plate, heat-resistant gray Iron Sheet,Plate -:- For detailed product information, please contact sales. -:

Packing of Nickel-Chromium-silicon Iron Sheet/Plate, heat-resistant gray 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 2955 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