Nickel and nickel alloys · Alloy 602 CA / Nicrofer 6025 HT / UNS N06025 / 2.4633
Heat-Resistant Nickel Alloy Alloy 602 CA (2.4633): Technical Overview
Engineering Parameters of Alloy 602 CA (UNS N06025)
| Supply Forms | Material Marking | Specifications | International Equivalents | International Equivalents | ||
|---|---|---|---|---|---|---|
| Sheet, Strip, Wire, Bar (Rods), Plates | Alloy 602 CA, Nicrofer 6025 HT, VDM Alloy 602 CA, UNS N06025 | ASTM: B 166, B 168 | ASME: SB 166, SB 168 | W.Nr. 2.4633 | EN: NiCr25FeAlY - 10302 | DIN: 17742, 17750, 17752; ISO: 286 |
Alloy 602 CA (UNS N06025) is an advanced heat-resistant nickel-based alloy, alloyed with high chromium, aluminum, and yttrium content. This composition ensures the formation of a dense and adhesively strong oxide film, guaranteeing unique resistance to high-temperature oxidation and creep at operating temperatures reaching up to 1200 °C. Rolled products from EV Group China are supplied in a heat-treated (annealed) condition with a pickled or oxidized surface, which ensures a homogeneous microstructure necessary for operation under cyclic thermomechanical stresses.
Chemical Composition of Alloy 602 CA, % (according to ASTM B168)
| Ni | Base |
|---|---|
| S | <0,01 |
| Zr | 0,01-0,1 |
| P | <0,02 |
| Y | 0,05-0,12 |
| Cu | <0,1 |
| Ti | 0,1-0,2 |
| C | 0,15-0,25 |
| Mn | <0,5 |
| Si | <0,5 |
| Al | 1,8-2,4 |
| Fe | 8,0-11,0 |
| Cr | 24,0-26,0 |
Engineering note: Slight variations in the content of alloying elements are permissible within ASTM/ASME specifications. For example, UNS N06025 standard sets the maximum manganese (Mn) content at 0.15%.
Mechanical Characteristics of Alloy 2.4633 Depending on Temperature
| Temperature (°C) | Yield Strength Rp0,2 (MPa) | Tensile Strength Rm (MPa) | Elongation (%) |
|---|---|---|---|
| 20 | 270 | 675 | 30 |
| 200 | 220 | 625 | 30 |
| 400 | 190 | 580 | 30 |
| 600 | 175 | 520 | 30 |
| 700 | 170 | 420 | 30 |
The presented values for mechanical properties are typical for the material in the solution-annealed condition and apply to the following product forms:
- Sheets and plates: thickness up to 50 mm
- Strip: thickness up to 3 mm
- Bars and forgings: diameter/cross-section up to 100 mm
- Wire: diameter up to 12 mm
Key Physical and Thermophysical Properties
The density of the alloy at room temperature is 7.93 g/cm³. The material is characterized by high thermal conductivity and a stable coefficient of thermal linear expansion over a wide temperature range, which minimizes internal stresses during cyclic thermal shocks.
Key Operational Advantages
Compared to Alloy 601, grade 602 CA demonstrates superior oxidation resistance. This is achieved through the synergistic effect of chromium and high aluminum content, which form a self-healing, impermeable Al₂O₃ oxide film on the surface. This barrier layer provides reliable protection against high-temperature gas corrosion, including in environments containing sulfur compounds.
Welding Technology and Welding Materials
The alloy exhibits good weldability with all standard arc welding methods (TIG, MIG, MMA). To obtain a welded joint with equivalent heat resistance and corrosion resistance to the base metal, EV Group China recommends using specialized welding materials: FM 602 CA wire (W. Nr. 2.4649 / AWS A5.14 ERNiCrFe-12).
Main Areas of Industrial Application
- Components for industrial furnaces and heat treatment equipment: muffles, retorts, radiant tubes, rollers, and conveyor belts.
- High-temperature assemblies in petrochemistry and reforming: parts for ammonia synthesis, methanol production, and hydrogen production plants.
- Automotive industry: components for exhaust gas aftertreatment systems, oxygen sensors, glow plugs for diesel engines.
- Equipment for vitrification of high-level radioactive waste, including components for melting furnaces.