High-Nickel Iron Sheet,Plate, heat-resistant gray Iron Sheet,Plate

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

High-Nickel Iron, heat-resistant gray iron Product Information -:- For detailed product information, please contact sales. -: ## **Product Introduction: High-Nickel Heat-Resistant Gray Iron (Ni-Resist Heat-Resistant Grades)** High-Nickel Heat-Resistant Gray Iron, a specialized subgroup within the Ni-Resist family, is an austenitic cast iron engineered to provide exceptional long-term stability and oxidation resistance at elevated temperatures. Unlike standard high-nickel corrosion-resistant grades, these alloys are specifically optimized for service in high-temperature oxidizing, reducing, and thermal cycling environments, typically ranging from **650°C to 950°C (1200°F to 1740°F)**. The key to its performance lies in the stable austenitic matrix formed by high nickel content, which effectively eliminates harmful phase transformations upon heating and cooling, thus preventing growth and distortion while forming a tenacious, self-healing oxide layer. This material offers a unique combination of excellent high-temperature strength, resistance to thermal fatigue, good castability, and relative ease of machining, making it a preferred choice for complex, load-bearing components in severe thermal service. --- ### **1. Chemical Composition** Heat resistance is achieved by balancing nickel, chromium, and silicon to create a stable, oxidation-resistant austenitic structure. Carbon content is carefully controlled for strength and graphite formation. **Typical Composition of Key Heat-Resistant Grades:** | Element | Grade D-5S / Type 4 (High Temp) | Grade D-5S / Type 5 (High Temp, High Strength) | Primary Function in Heat Resistance | | :--- | :--- | :--- | :--- | | **Nickel (Ni)** | **13.5 - 17.5%** | **34.0 - 36.0%** | **Primary austenite stabilizer.** Prevents ferrite formation and the associated alpha-gamma phase change, eliminating growth. Provides fundamental strength and toughness at temperature. | | **Chromium (Cr)** | **1.75 - 2.50%** | **1.75 - 2.50%** | **Critical for oxidation resistance.** Forms a durable Cr₂O₃-rich surface scale, protecting against scaling and carburization. Increases elevated temperature strength. | | **Silicon (Si)** | **5.00 - 6.00%** | **5.00 - 6.00%** | **Synergistic oxidant.** Promotes formation of a dense, adherent SiO₂-Cr₂O₃ complex scale. Significantly increases scaling temperature and growth resistance. | | **Carbon (C)** | **2.40 - 3.00%** | **1.60 - 2.40%** | Provides graphite for thermal shock resistance and machinability. Lower carbon in high-Ni grades increases alloy stability and strength. | | **Manganese (Mn)** | 0.40 - 1.00% | 0.40 - 1.00% | Counteracts sulfur and provides solid solution strengthening. | | **Copper (Cu)** | ≤ 0.50% | ≤ 0.50% | May be present in some grades for added corrosion resistance. | | **Iron (Fe)** | Balance | Balance | Base metal. | **Microstructural Note:** The target microstructure is a **fully austenitic matrix** with a uniform distribution of **Type A flake graphite**. No pearlite or ferrite should be present in the heat-treated condition, ensuring dimensional stability. --- ### **2. Physical & Mechanical Properties at Room & Elevated Temperature** Properties are defined by remarkable retention of strength and resistance to degradation under thermal exposure. | Property | Typical Value / Description | | :--- | :--- | | **Microstructure** | **Austenitic matrix with flake graphite** (critical for growth resistance). | | **Density** | ~7.1 - 7.3 g/cm³ | | **Tensile Strength (Room Temp)** | **170 - 310 MPa (25 - 45 ksi)** – Varies by grade; higher Ni grades offer greater strength. | | **Yield Strength (0.2% Offset)** | **140 - 260 MPa (20 - 38 ksi)** | | **Elongation** | 1 - 3% | | **Hardness (Room Temp)** | **140 - 210 HB** | | **Maximum Service Temperature** | **Type 4: Up to 815°C (1500°F)**
**Type 5: Up to 950°C (1740°F)** in continuous oxidizing service. | | **Growth Resistance** | **Outstanding.** Exhibits minimal permanent growth (<0.1% after 1000h at 870°C) due to the stable austenite. | | **Oxidation/Scaling Resistance** | **Excellent.** The Si-Cr-Ni alloying promotes a highly protective, adherent, and slow-growing oxide scale. | | **Thermal Conductivity** | Moderate (~12-15 W/m·K). Lower than low-alloy gray iron, but sufficient for many applications. | | **Thermal Shock Resistance** | **Very Good to Excellent.** The austenitic matrix is ductile, and graphite flakes help arrest crack propagation. | | **Creep & Rupture Strength** | Good. Superior to other gray irons at temperatures above 650°C. | | **Machinability** | Good (similar to standard gray iron of equivalent hardness). | --- ### **3. Key Product Advantages & Characteristics** * **Exceptional Growth Resistance:** The invariant austenitic structure is the most stable of all cast irons upon thermal cycling, ensuring dimensional integrity. * **Superior Oxidation & Scaling Resistance:** The combined effect of Ni, Cr, and Si creates a formidable barrier against high-temperature gas corrosion. * **Retained Ductility & Toughness at Temperature:** Maintains better fracture resistance under thermal stress compared to ferritic heat-resistant irons. * **Good Castability and Machinability:** Allows for the production of complex, thin-walled castings that can be readily machined. * **Non-Magnetic:** A valuable characteristic for specific furnace and electrical applications. --- ### **4. Product Applications** This material is specified for complex, high-integrity components subjected to severe and cyclic thermal stresses. * **Heat Treatment & Industrial Furnaces:** Retorts, carburizing boxes, furnace trays, fan blades, radiant tubes, muffles, chain links for conveyor belts. * **Power Generation:** Turbocharger housings for large diesel engines, exhaust manifolds, heat exchanger parts. * **Chemical & Petrochemical:** Reformers, pyrolysis tubes, fittings, and supports in high-temperature process streams. * **Glass Manufacturing:** Mold blocks, plungers, and handling tools for molten glass. * **Engine & Exhaust Systems:** High-performance exhaust manifolds and turbo housings requiring resistance to thermal fatigue. --- ### **5. International Standards** These alloys are covered under standards for austenitic cast irons, with specific grades designated for high-temperature service. | Standard | Title / Scope | Common Designations / Notes | | :--- | :--- | :--- | | **ASTM A436** | *Standard Specification for Austenitic Gray Iron Castings* | **Type 4 (D-5S)** and **Type 5 (D-5S)** are the primary high-temperature, high-silicon grades. This is the key ASTM standard. | | **ISO 2892** | *Austenitic cast irons* | **JLW/HR/ANi20Si5Cr2** (Example: designates a Ni-Resist with ~20% Ni, 5% Si, 2% Cr for heat resistance). | | **EN 13835** | *Founding - Austenitic cast irons* (European) | **EN-GJLA-XNiSiCr20-5-2** (Material Number). This systematic designation clearly shows the Ni-Si-Cr content for heat-resistant types. | | **JIS G5510** | *Austenitic cast irons* (Japanese) | **FCA-Ni20Cr2Si5** or similar notations indicating high silicon. | | **GB/T 27748** | *Heat resistant austenitic cast iron* (Chinese) | **NTK Si5** series, which specifically standardizes high-nickel, high-silicon heat-resistant grades. | **Specification Note:** When ordering, it is critical to specify the **standard and the type/grade (e.g., ASTM A436 Type 5)** to ensure the correct high-temperature chemistry (particularly the high Si content) is supplied, as opposed to standard Ni-Resist corrosion grades. --- ### **Conclusion** High-Nickel Heat-Resistant Gray Iron (Ni-Resist HT) is the premier choice for demanding applications where **dimensional stability under thermal cycling is as critical as oxidation resistance**. Its **stable austenitic matrix, fortified by high silicon and chromium**, provides an unmatched defense against growth, scaling, and thermal fatigue. While representing a higher initial cost than medium-silicon or high-chromium irons, its reliability and longevity in complex, high-stress thermal components—such as furnace retorts and turbocharger housings—make it a cost-effective engineering solution for extreme service conditions. It stands as a testament to the capability of alloyed cast iron to perform in environments approaching those reserved for exotic alloys. -:- For detailed product information, please contact sales. -: High-Nickel Iron, heat-resistant gray iron Specification Dimensions Size： Diameter 20-1000 mm Length <6483 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-Nickel Iron, heat-resistant gray iron Properties -:- For detailed product information, please contact sales. -:

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

Packing of High-Nickel 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 2954 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