Hastelloy D-205 Corrosion Resistant Alloy,D205，1

### **Hastelloy® D-205 Alloy (UNS N06205) - High-Silicon Nickel-Based Corrosion Resistant Alloy** #### **Overview** **Hastelloy® D-205 Alloy** is a specialized nickel-based corrosion-resistant alloy specifically engineered for exceptional performance in highly corrosive sulfuric acid environments. This high-silicon nickel alloy belongs to the Hastelloy D-series, which is particularly renowned for outstanding resistance to sulfuric acid across a wide range of concentrations and temperatures. The alloy's unique composition makes it indispensable for severe corrosive applications where conventional materials fail rapidly. --- #### **Chemical Composition (Weight %)** | Element | Content (%) | Function | |---------|-------------|-----------| | **Nickel (Ni)** | **Balance** | **Base element providing corrosion resistance** | | **Silicon (Si)** | **2.75-3.25** | **Primary element for sulfuric acid resistance** | | **Chromium (Cr)** | **20.0-23.0** | **Oxidation resistance and passivation enhancement** | | **Copper (Cu)** | **1.5-2.5** | **Improves resistance to reducing environments** | | **Molybdenum (Mo)** | **2.0-4.0** | **Enhances pitting and crevice corrosion resistance** | | **Iron (Fe)** | **≤ 3.0** | **Controlled impurity** | | **Manganese (Mn)** | **≤ 1.0** | **Deoxidizer and sulfur control** | | **Carbon (C)** | **≤ 0.08** | **Controlled for carbide formation** | | **Tungsten (W)** | **≤ 1.0** | **Optional addition for property enhancement** | | **Other Elements** | **≤ 0.5** | **Total other impurities** | --- #### **Physical Properties** | Property | Value / Description | |----------|---------------------| | **Density** | **8.08 g/cm³ (0.292 lb/in³)** | | **Melting Range** | **1280-1350°C (2336-2462°F)** | | **Electrical Resistivity** | **1.15 μΩ·m** | | **Thermal Conductivity** | **12.5 W/m·K (at 100°C)** | | **Coefficient of Thermal Expansion** | **13.2 μm/m·°C (20-400°C)** | | **Specific Heat Capacity** | **450 J/kg·K** | | **Magnetic Permeability** | **< 1.01 (slightly magnetic)** | --- #### **Mechanical Properties (Annealed Condition)** | Temperature | Tensile Strength | Yield Strength (0.2%) | Elongation | Hardness | |-------------|------------------|---------------------|------------|----------| | **Room Temperature** | **690 MPa (100 ksi)** | **310 MPa (45 ksi)** | **40%** | **200 HB** | | **200°C (392°F)** | **620 MPa (90 ksi)** | **275 MPa (40 ksi)** | **35%** | **185 HB** | | **400°C (752°F)** | **585 MPa (85 ksi)** | **260 MPa (38 ksi)** | **32%** | **175 HB** | --- #### **Corrosion Resistance Performance** | Environment | Concentration | Temperature | Performance | |-------------|---------------|-------------|-------------| | **Sulfuric Acid** | **0-98%** | **Up to boiling point** | **Excellent** | | **Phosphoric Acid** | **All concentrations** | **Up to 150°C** | **Excellent** | | **Hydrochloric Acid** | **Dilute solutions** | **Room temperature** | **Good** | | **Nitric Acid** | **< 20%** | **Room temperature** | **Good** | | **Mixed Acids** | **Various** | **Moderate temperatures** | **Very Good** | --- #### **Key Characteristics & Applications** **Key Characteristics:** - **Exceptional Sulfuric Acid Resistance**: Superior performance across all concentrations - **High Silicon Content**: Provides unique corrosion resistance characteristics - **Good Mechanical Properties**: Balanced strength and ductility - **Moderate Fabricability**: Can be machined and welded with proper techniques - **Thermal Stability**: Maintains properties at elevated temperatures - **Economic Service Life**: Extended longevity in severe environments **Typical Applications:** - **Sulfuric Acid Production**: Reactors, concentrators, and handling systems - **Chemical Processing**: Pickling tanks, acid recovery systems, and storage vessels - **Petrochemical Industry**: Alkylation units and acid catalyst systems - **Metal Processing**: Acid pickling lines and surface treatment equipment - **Fertilizer Production**: Sulfuric acid-based process equipment - **Waste Acid Recovery**: Regeneration systems and concentration units - **Laboratory Equipment**: Acid handling and testing apparatus --- #### **International Standards & Specifications** | Standard | Designation | Description | |----------|-------------|-------------| | **UNS** | **N06205** | **Unified Numbering System** | | **ASTM** | **B574** | **Rod and Bar Specification** | | **ASTM** | **B575** | **Plate, Sheet, and Strip** | | **ASME** | **SB-574** | **Boiler and Pressure Vessel Code** | | **DIN** | **2.4685** | **German Standard Designation** | | **ISO** | **6208** | **Nickel Alloy Plate and Sheet** | --- #### **Manufacturing & Processing** **Available Forms:** - **Plate and Sheet**: 3 mm to 50 mm thickness - **Bar and Rod**: 10 mm to 200 mm diameter - **Pipe and Tube**: 15 mm to 300 mm diameter - **Cast Components**: Specialized shapes and fittings - **Welding Products**: Electrodes and filler wires **Processing Guidelines:** - **Hot Working**: 1100-1150°C (2012-2102°F) - **Cold Working**: Limited capability due to high silicon content - **Annealing**: 1050-1100°C (1922-2012°F) with controlled cooling - **Welding**: Requires specialized procedures and filler materials - **Machining**: Challenging due to abrasiveness; requires carbide tools --- #### **Heat Treatment & Microstructural Control** | Process | Temperature Range | Purpose | |---------|------------------|---------| | **Solution Annealing** | **1050-1100°C** | **Homogenize microstructure** | | **Stress Relieving** | **850-900°C** | **Reduce residual stresses** | | **Stabilization** | **700-750°C** | **Improve corrosion resistance** | --- #### **Quality Control & Testing** - **Chemical Analysis**: Per ASTM E1473 - **Mechanical Testing**: Per ASTM E8/E8M - **Corrosion Testing**: ASTM G28 and G31 methods - **Non-Destructive Testing**: UT, RT, PT as required - **Metallographic Examination**: Per ASTM E3 - **Hardness Testing**: Per ASTM E10 --- #### **Comparison with Competitive Alloys** | Property | D-205 | C-276 | B-2 | 20Cb-3 | |----------|-------|-------|-----|---------| | **Sulfuric Acid Resistance** | **Excellent** | Good | Poor | Very Good | | **Silicon Content** | **3.0%** | 0.08% | 0.10% | 0.30% | | **Fabricability** | **Moderate** | Excellent | Good | Excellent | | **Cost Effectiveness** | **High** | Medium | High | Medium | --- #### **Summary** **Hastelloy® D-205 Alloy** represents a specialized corrosion-resistant material optimized for severe sulfuric acid service and related corrosive environments. Its high silicon content, combined with balanced nickel-chromium-molybdenum-copper additions, provides exceptional resistance to sulfuric acid across the complete concentration range. While presenting some fabrication challenges due to its unique composition, the alloy delivers unparalleled performance in specific severe corrosive applications where other materials rapidly deteriorate. Supported by established international standards and proven field experience, D-205 continues to be the material of choice for sulfuric acid production, chemical processing, and acid recovery applications where reliability and extended service life are critical requirements.

Packing of Standard Packing: Typical bulk packaging includes palletized plastic 5 gallon/25 kg. pails, fiber and steel 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 3248 gallon liquid totes Special package is available on request.