Nickel and nickel alloys · Alloy 31 Plus / Nicrofer 3426 hMo / UNS N08034 / 2.4692
Alloy 31 Plus (UNS N08034): Technical Characteristics and Application
Technical Characteristics of Alloy 31 Plus
| Product Form | Parameter | Value |
|---|---|---|
| Analogs | Sheet, plate, rod, wire, bar, strip | 2.4692 |
| Analogs | Sheet, plate, rod, wire, bar, strip | NiFeCr27Mo6CuN |
| Alloy Name | Sheet, plate, rod, wire, bar, strip | Alloy 31 Plus, Nicrofer 3426 hMo, VDM Alloy 31 Plus, UNS N08034 |
| Alloy Name | Sheet, plate, rod, wire, bar, strip | Alloy 31 Plus, Nicrofer 3426 hMo, VDM Alloy 31 Plus, UNS N08034 |
| Analogs | Sheet, plate, rod, wire, bar, strip | ISO |
| Analogs | Sheet, plate, rod, wire, bar, strip | W.Nr. |
Alloy 31 Plus is a high-performance nickel-iron-chromium-molybdenum alloy, nitrogen-alloyed. The optimization of the nickel component compared to the base Alloy 31 provides this material with increased structural stability and improved operational characteristics in exceptionally aggressive environments. This makes it indispensable for critically important industrial applications where maximum corrosion resistance and mechanical strength are required.
Chemical Composition of Alloy 31 Plus (in %)
| Ni | Parameter | Value |
|---|---|---|
| 33.5-35.0 | Al | <30 |
| 33.5-35.0 | C | <0.01 |
| 33.5-35.0 | Cr | 26.0-27.0 |
| 33.5-35.0 | Cu | 0.5-1.5 |
| 33.5-35.0 | Fe | remainder |
| 33.5-35.0 | Mn | 1.0-4.0 |
| 33.5-35.0 | Mo | 6.0-7.0 |
| 33.5-35.0 | N | 0.10-0.25 |
| 33.5-35.0 | P | <0.02 |
| 33.5-35.0 | S | <0.01 |
| 33.5-35.0 | Si | <0.1 |
Mechanical Properties of Alloy 31 Plus
| Temperature | Parameter | Value |
|---|---|---|
| Yield Strength, Rp0.2 | 100 | 210 |
| Yield Strength, Rp0.2 | 100 | 30.5 |
| Yield Strength, Rp0.2 | 20 | 280 |
| Yield Strength, Rp0.2 | 20 | 40.6 |
| Yield Strength, Rp0.2 | 200 | 180 |
| Yield Strength, Rp0.2 | 200 | 26.1 |
| Yield Strength, Rp0.2 | 300 | 165 |
| Yield Strength, Rp0.2 | 300 | 23.9 |
| Yield Strength, Rp0.2 | 400 | 150 |
| Yield Strength, Rp0.2 | 400 | 21.8 |
| Yield Strength, Rp0.2 | 500 | 135 |
| Yield Strength, Rp0.2 | 500 | 19.6 |
| Yield Strength, Rp0.2 | °C | ksi |
| Yield Strength, Rp0.2 | °C | MPa |
| Yield Strength, Rp1.0 | 100 | 240 |
| Yield Strength, Rp1.0 | 100 | 34.8 |
| Yield Strength, Rp1.0 | 20 | 310 |
| Yield Strength, Rp1.0 | 20 | 45 |
| Yield Strength, Rp1.0 | 200 | 210 |
| Yield Strength, Rp1.0 | 200 | 30.5 |
| Yield Strength, Rp1.0 | 300 | 195 |
| Yield Strength, Rp1.0 | 300 | 28.3 |
| Yield Strength, Rp1.0 | 400 | 180 |
| Yield Strength, Rp1.0 | 400 | 26.1 |
| Yield Strength, Rp1.0 | 500 | 165 |
| Yield Strength, Rp1.0 | 500 | 23.9 |
| Yield Strength, Rp1.0 | °C | ksi |
| Yield Strength, Rp1.0 | °C | MPa |
| Elongation | 20 | 40 |
| Tensile Strength Rm | 20 | 650-850 |
| Tensile Strength Rm | 20 | 94.3-123 |
| Temperature | 20 | 68 |
| Elongation | 100 | - |
| Tensile Strength Rm | 100 | - |
| Tensile Strength Rm | 100 | - |
| Temperature | 100 | 212 |
| Elongation | 200 | - |
| Tensile Strength Rm | 200 | - |
| Tensile Strength Rm | 200 | - |
| Temperature | 200 | 392 |
| Elongation | 300 | - |
| Tensile Strength Rm | 300 | - |
| Tensile Strength Rm | 300 | - |
| Temperature | 300 | 572 |
| Elongation | 400 | - |
| Tensile Strength Rm | 400 | - |
| Tensile Strength Rm | 400 | - |
| Temperature | 400 | 762 |
| Elongation | 500 | - |
| Tensile Strength Rm | 500 | - |
| Tensile Strength Rm | 500 | - |
| Temperature | 500 | 932 |
| Elongation | °C | % |
| Tensile Strength Rm | °C | ksi |
| Tensile Strength Rm | °C | MPa |
| Temperature | °C | °F |
Physical Properties
The density of Alloy 31 Plus is 8.08 g/cm³. This parameter is critical for calculating the mass of structures and assessing specific strength in engineering applications.
Thermal Characteristics
| Temperature | Parameter | Value |
|---|---|---|
| °C | Coefficient of Expansion | 10⁻⁶/K |
| °C | Coefficient of Expansion | 10⁻⁶/°F |
| °C | Modulus of Elasticity | 10⁶ psi |
| 20 | Coefficient of Expansion | 14.3 |
| 20 | Coefficient of Expansion | 7.94 |
| 20 | Modulus of Elasticity | 199 |
| 20 | Modulus of Elasticity | 28.9 |
| 20 | Temperature | 68 |
| 20 | Thermal Conductivity | 10.3 |
| 20 | Thermal Conductivity | 5.95 |
| 20 | Specific Heat | 0.103 |
| 20 | Specific Heat | 431 |
| 100 | Coefficient of Expansion | 14.8 |
| 100 | Coefficient of Expansion | 8.22 |
| 100 | Modulus of Elasticity | 195 |
| 100 | Modulus of Elasticity | 28.3 |
| 100 | Temperature | 212 |
| 100 | Thermal Conductivity | 11.6 |
| 100 | Thermal Conductivity | 6.70 |
| 100 | Specific Heat | 0.107 |
| 100 | Specific Heat | 447 |
| 200 | Coefficient of Expansion | 15.4 |
| 200 | Coefficient of Expansion | 8.56 |
| 200 | Modulus of Elasticity | 189 |
| 200 | Modulus of Elasticity | 27.4 |
| 200 | Temperature | 392 |
| 200 | Thermal Conductivity | 13.4 |
| 200 | Thermal Conductivity | 7.74 |
| 200 | Specific Heat | 0.112 |
| 200 | Specific Heat | 468 |
| 300 | Coefficient of Expansion | 16.0 |
| 300 | Coefficient of Expansion | 8.89 |
| 300 | Modulus of Elasticity | 181 |
| 300 | Modulus of Elasticity | 26.3 |
| 300 | Temperature | 572 |
| 300 | Thermal Conductivity | 14.9 |
| 300 | Thermal Conductivity | 8.61 |
| 300 | Specific Heat | 0.115 |
| 300 | Specific Heat | 480 |
| 400 | Coefficient of Expansion | 16.3 |
| 400 | Coefficient of Expansion | 9.06 |
| 400 | Modulus of Elasticity | 174 |
| 400 | Modulus of Elasticity | 25.2 |
| 400 | Temperature | 752 |
| 400 | Thermal Conductivity | 16.3 |
| 400 | Thermal Conductivity | 9.42 |
| 400 | Specific Heat | 0.117 |
| 400 | Specific Heat | 488 |
| 500 | Coefficient of Expansion | 16.3 |
| 500 | Coefficient of Expansion | 9.06 |
| 500 | Modulus of Elasticity | 168 |
| 500 | Modulus of Elasticity | 24.4 |
| 500 | Temperature | 932 |
| 500 | Thermal Conductivity | 10.17 |
| 500 | Thermal Conductivity | 17.6 |
| 500 | Specific Heat | 0.117 |
| 500 | Specific Heat | 488 |
| °C | Modulus of Elasticity | GPa |
| °C | Temperature | °F |
| °C | Thermal Conductivity | Btu*in/sq.ft*h*°F |
| °C | Thermal Conductivity | W/m*°C |
| °C | Specific Heat | Btu/lb*°F |
| °C | Specific Heat | J/kg*°C |
Corrosion Resistance
Alloy 31 Plus demonstrates exceptional resistance to intergranular corrosion, as confirmed by tests according to ASTM-G 28, method A. The corrosion rate does not exceed 0.5 mm/year (0.020 mpy) both in the as-supplied condition and after welding operations. The alloy effectively resists pitting and crevice corrosion, showing performance similar to classic Alloy 31, which makes it optimal for operation in highly aggressive chemical environments.
Technological Aspects of Welding
When working with Alloy 31 Plus, EV Group China engineers strongly recommend adhering to strict cleanliness protocols. This includes using only stainless steel brushes, completely avoiding contact with ferrous metals, and mandatory argon shielding of the weld root with high purity (not less than 99.99%). These measures are critically important to prevent contamination and ensure maximum corrosion resistance of welded joints.
- Welding methods: TIG and MAG (pulsed arc welding is preferred for optimal heat input control).
- Recommended fillers: FM 59 (ER NiCrMo-13), ensuring weld homogeneity and preservation of base metal properties.
- Interpass temperature: not above 120°C to minimize thermal stresses and prevent the formation of undesirable phases.
Key Advantages of Alloy 31 Plus from EV Group China
- Highest chemical resistance in sulfuric acid and phosphoric acid environments, critical for the chemical industry.
- Optimized heat treatment temperature, ensuring microstructural stability and mechanical properties.
- High workability during mechanical processing and forming, which simplifies the production of complex components.
- Excellent weldability with strict adherence to regulations, guaranteeing the reliability and durability of structures.
Main Areas of Industrial Application
- Phosphoric acid production (wet process): where aggressive environments require maximum corrosion resistance.
- Flue gas desulfurization plants: for operation in conditions of high humidity and the presence of sulfur compounds.
- Hydrometallurgical processes (including HPAL): where the alloy withstands extreme temperatures and pressure in combination with aggressive solutions.
- Equipment for marine and brackish water applications: to prevent corrosion in chloride environments.
- Pickling baths for aggressive acid mixtures: ensuring the longevity of equipment in conditions of intense chemical attack.
- Pulp and paper industry: where the alloy demonstrates resistance to bleaching agents and other aggressive chemicals.