Inconel686 Nickel Alloy Physical Properties Composition Technology Standard
Inconel 686 has the following characteristics:
1. It has good corrosion resistance to reducing, oxidizing and nitriding media
2. Good resistance to stress corrosion cracking at room temperature and high temperature
3. Good corrosion resistance to dry chlorine and hydrogen chloride gases
4. Have good mechanical properties at zero, room temperature and high temperature
5. It has good creep rupture strength and is recommended to be used above 700
The metallographic structure of Inconel 686;
Inconel 686 has a face-centered cubic lattice structure.
Corrosion resistance of Inconel 686;
Alloy 686 has corrosion resistance to various corrosive media. Chromium gives the alloy better corrosion resistance under oxidizing conditions than Nickel 99.2 (Alloy 200) and Nickel 99.2 (Alloy 201, low carbon). At the same time, the higher nickel content gives the alloy good corrosion resistance in reducing conditions and alkaline solutions, and can effectively prevent stress corrosion cracking of ferric chloride. Alloy 686 has good corrosion resistance in organic acids such as acetic acid, acetic acid, formic acid, and stearic acid, and moderate corrosion resistance in inorganic acids. It has excellent corrosion resistance in high-purity water used in single and double cycles in nuclear reactors. The outstanding performance of 686 is that it can resist the corrosion of dry chlorine and hydrogen chloride, and the service temperature can reach 650. At high temperatures, annealed and solution treated alloys have good oxidation resistance and high strength in air. The alloy can also resist ammonia gas and nitriding and carburizing atmospheres. However, when the redox conditions alternate, the alloy will be corroded by some oxidizing media (such as green dead liquid).
Inconel 686 process performance and requirements:
Thermal processing
1. Thermal working temperature is 1200℃~900℃, and the cooling method is water quenching or rapid air cooling.
To obtain the best corrosion resistance and the most suitable crystal structure, heat treatment should be carried out after heat treatment.
3. Raw materials can be directly fed into the heating furnace.
Cold working
1. Cold work materials should be annealed or solution heat treated. The work hardening rate of 686 alloy is close to that of austenitic stainless steel, and similar processing equipment can be used.
2. Intermediate annealing should be performed during cold working.
3. When the cold working capacity is greater than 5%, the workpiece needs to be solution treated.
4. In order to reduce material wear, alloy tool steel, carbide or cast steel should be selected as the mold.
Inconel 686 welding process
This alloy has good welding properties and can be connected by arc welding, argon arc welding, resistance welding and brazing. Large or complex welded structures should be annealed at 870°C for 1 hour after welding to eliminate welding stress.
GB/T1689-1993 Inconel 686 piece heat treatment process
The heat treatment of parts should be carried out in accordance with the corresponding material standard heat treatment system. Annealing of sheet and strip parts should be carried out in a protective atmosphere.
The application fields of Inconel 686 are as follows: 1. Application of thermowells in corrosive atmospheres
2. Vinyl chloride monomer production: chlorine resistance, hydrogen chloride resistance, oxidation resistance, carbonation corrosion resistance
3. Oxidation converts uranium into hexafluoride: resistant to hydrogen fluoride corrosion
4. Fields of production and use of corrosive alkali metals, especially environments where sulfides are used.
5. Preparation of titanium dioxide from chlorine gas
6. Production of organic or inorganic chlorides and fluorides: resistant to chlorine and fluorine corrosion
7. Nuclear Reactor
8. Heat treatment furnaces, especially curved neck bottles and components in carbonizing and nitriding atmospheres
9. It is recommended to use 686 alloy as a catalytic regenerator in petrochemical production above 700℃ to obtain a longer period of time.
