Hastelloy C-2000
Material grade: Hastelloy C-2000
US grade: NO6200
German grade: 2.4675    
1.Overview of Hastelloy C-2000 (N06200, 2.4675):

Hastelloy C-2000 (N06200, 2.4675) is a nickel-based high-temperature alloy composed of elements such as nickel, molybdenum, and chromium, with a nickel content of about 55%.
Hastelloy C-2000 is an optimized alloy developed for expanded material applications, starting from a conceptual idea of adding copper to the already established Ni-Cr-Mo alloys. Since its market introduction at the end of 1995, it has received significant recognition due to its inherent versatility. Technological innovations have not only improved the alloy's resistance to aqueous corrosion but also expanded the overall application range of Ni-Cr-Mo family alloys. This new material is designed to resist more corrosive chemicals, including sulfuric acid, hydrochloric acid, and hydrofluoric acid. Unlike previously optimized Ni-Cr-Mo alloys that could only resist either oxidizing or reducing acids, C-2000 has corrosion resistance in both environments. The combined effect of molybdenum and copper (at levels of 16% and 1.6%, respectively) gives the alloy excellent resistance to reducing medium corrosion, while the high chromium content (23% wt) ensures resistance to oxidizing medium corrosion.
From an engineering perspective, C-2000 offers significant potential for increased production. When used in place of the original Ni-Cr-Mo alloys, its enhanced corrosion resistance can achieve longer equipment life at the same material thickness and provide a higher safety factor under harsher conditions. The improvement in corrosion resistance allows equipment to be used for multiple purposes (reactors, heat exchangers, valves, pumps, etc.), resulting in greater returns on investment; for example, a reactor can adapt from hydrochloric acid mixtures to another working condition of nitric acid-based mixtures. Due to the versatility of C-2000, it is the best nickel-based alloy material that can adapt to various processes. The C-2000 alloy expands the use of Ni-Cr-Mo alloys in various corrosive environments, possessing excellent corrosion resistance to oxidizing media as well as outstanding resistance to reducing environments. The excellent performance of C-2000 has led to breakthroughs in chemical industry equipment applications.
The high chromium content is used to resist corrosion from oxidizing media, such as iron ions, copper ions, and dissolved oxygen. Reducing media, such as dilute hydrochloric acid or sulfuric acid, require high molybdenum + tungsten content. The limitations of metallurgical stability make it difficult to optimize both simultaneously. Hastelloy C-2000 solves this dilemma in alloy design.
The high chromium content combined with molybdenum and copper provides sufficient resistance to reducing environment corrosion without sacrificing metallurgical stability. The C-2000 alloy shows superior resistance to pitting and crevice corrosion compared to the industrial standard C-276 alloy. Its forming, welding, and machining performance is similar to C-276, and C-2000 alloy is available in various shapes: plates, sheets, forgings, bars, wires, welding rods, and pipes, all of which are subjected to final solution heat treatment before delivery, unless the customer has special requirements. Hastelloy C-2000 is included in ASME, ASTM standards B-564, B-574, B-575, B-619, B-622, B-366. The DIN standard number is No.2.4675, and NiCr23Mo16Cu. The unified number UNS for C-2000 alloy is N06200, but stricter composition control during production is implemented to enhance performance.
2. Chemical composition of Hastelloy C-2000 (N06200, 2.4675): see Table 1-1.
Table 1-1                                                         %

3.Physical properties of Hastelloy C-2000 (N06200, 2.4675):
1. Density of Hastelloy C-2000: 8.5g/cm3, melting point: 1399℃.
2. Elastic modulus of Hastelloy C-2000: 206kN/mm2, thermal conductivity: 10.8 W/m-k.
3. Hardness of Hastelloy C-2000: HRC90.
4. Coefficient of thermal expansion of Hastelloy C-2000 (25 - 100℃): 12.4 μm/m℃.
4.Welding performance of Hastelloy C-2000 (N06200, 2.4675):
1. Establish good safety working conditions before welding. Welders should have appropriate protection, avoid space restrictions, and ensure adequate ventilation. Follow the recommendations for welding and cutting safety according to ANSI/ASC Z49.1-88.
2. The welding surface and surrounding area should be thoroughly cleaned and free of oil before welding.
3. Ni-Cr-Mo alloys have the characteristic of low melting depth, requiring a suitable welding angle and minimal welding surface.
4. The interlayer temperature should be controlled below 93°C to avoid overheating. (Especially for welding thin materials.)
5. The welding metal exhibits viscous flow, so some typically necessary torch operations are required. Increasing the current will not significantly enhance the fluidity of the metal in the molten pool.
6. Oxy-acetylene welding and submerged arc welding are not recommended.
7. Unopened welding rods do not need to be dried. However, unused welding rods must be stored in an oven at a temperature of 121°C-204°C.
8. In gas shielded arc welding (tungsten or metal electrode), 100% argon protection should be used when welding the root pass. In manual arc welding, the back of the root pass must be polished.
9. For tungsten inert gas arc welding, it is recommended to use an arc welding power source equipped with high-frequency start and drooping control, and a torch with a gas diffusion lens can provide the most ideal gas protection.
10. Post-weld stress relief treatment for Ni-Cr-Mo alloys at around 650°C is inappropriate. Generally, no heat treatment is required after welding, but if stress relief is needed, it is recommended to perform complete solution annealing at 1149°C followed by water quenching.
11. If the oxidizing protective gas exceeds 1% in metal inert gas arc welding, it is recommended to polish the weld after each welding pass.
12. For gas shielded metal arc welding with spray transfer and synergistic transfer (over 120A), it is recommended to use water-cooled nozzles.
Five,Hastelloy C-2000 (N06200, 2.4675) specifications and supply status of Hastelloy alloy:
1. Variety classification: Hastelloy C-2000 seamless pipes, Hastelloy C-2000 steel plates, Hastelloy C-2000 round bars, Hastelloy C-2000 forgings, Hastelloy C-2000 flanges, Hastelloy C-2000 rings, Hastelloy C-2000 welded pipes, Hastelloy C-2000 steel strips, Hastelloy C-2000 wires and matching welding materials.
2. Delivery status: Seamless pipes: solution + acid pickling, length can be customized; plates: solution, acid washing, edge cutting; welded pipes: solution acid pickling + RT% flaw detection, forgings: annealed + turned; bars in forged state, surface polished or turned; strips delivered in cold-rolled, solution soft state, and descaled; wires delivered in solution acid-washed coil or straight bar form, solution straight bar finely polished.