Inconel625/inconel600/inconel718/inconel601 steel coil/strip manufacturer

1. Overview of Inconel625 (NO6625) superalloy:
Inconel625 is a solid-solution strengthened nickel-based deformed superalloy with molybdenum and niobium as the main strengthening elements. It has excellent corrosion resistance and oxidation resistance. It has good tensile properties and fatigue properties from low temperature to 980 °C, and is resistant to salt. Stress corrosion under fog atmosphere. Therefore, it can be widely used in the manufacture of aero-engine parts, aerospace structural parts and chemical equipment. The alloys are well processed and welded and are available in a wide range of plates, bars, tubes, wire, strip and forgings.
1. Material grade: Inconel625.
2. Similar grades of Inconel625: GH3625 (GH625) (China), UNS NO6625 (USA), NC22DNb (France), 2.4856 (Germany).
3. Chemical composition: see Table 1-1.
Table 1-1

4. Heat treatment system: bar: 950～1030℃, air cooling or water cooling; or 1090～1200℃, air cooling or water cooling solution treatment. Plate: 950～1030℃, air cooling; or 1090～1200℃, air cooling. Tube material: Recommended annealing temperature: 960～1030℃, air-cooled or water-cooled.
5. Variety, specification and supply status: It can supply bars with d25~80mm and plates with δ0.8~10.5mm, as well as seamless (welded) pipes with d6~40mm. Bars are delivered without heat treatment but in a polished or polished state; plates are supplied after solutionization and finishing; pipes are supplied after solutionization, pickling (or bright annealing).
6. Melting and casting process: The alloy is produced by vacuum induction furnace smelting plus electroslag remelting or vacuum induction furnace plus vacuum arc remelting process.
7. Application overview and special requirements: The alloy is used to manufacture engine casings, guide vanes, mounting edges, cylinders, fuel manifolds and other components. It has passed the actual application assessment. The maximum operating temperature is 950 °C; ℃ After long-term use, there is a certain age hardening phenomenon, which leads to some decline in the plasticity of the alloy.
2. Physical and chemical properties of Inconel625 (NO6625) superalloy:
1. Thermal performance:
(1), Inconel625 melting temperature range: 1290 ~ 1350 ℃ [1].
2. Inconel625 density: ρ=8.44g/cm3.
3. Magnetic properties of Inconel625: The alloy is non-magnetic.
4. Chemical properties of Inconel625:
(1) Anti-oxidation performance of Inconel625: The alloy has excellent high-temperature oxidation resistance. The weight change of the alloy after cyclic oxidation in air medium at high temperature is shown in Table 2-1.
table 2-1

Note: Circulating oxidation heating for 15min and cooling for 5min is a cycle.
(2) Corrosion resistance of Inconel625: The alloy has good seawater corrosion resistance, see Table 2-2. The alloy is also resistant to corrosion by various salt solutions. In addition, it has good corrosion resistance to nitric acid and phosphoric acid, and also has considerable resistance to the corrosion of hydrochloric acid heated to below the boiling point and low concentration of sulfuric acid.
Table 2-2

Note: The smooth sample refers to a flat sample with a circular weld of 6.4mm×100mm×300mm, which is annealed at 980℃ before welding. Specimens with gaps are bolted to the center of the panel with 32mm fiber washers.
3. Mechanical properties of Inconel625 (NO6625) superalloy:
Performance specified by Inconel625 technical standard: See Table 3-1
Table 3-1

① Standard Z9-0105-1990. ②Standard Z9-0104-1990 and GJB 3317-1998.

4. Microstructure of Inconel625 (NO6625) superalloy:

1. Inconel625 phase transition temperature

2. Inconel625 time-temperature-structure transformation curve

3. Microstructure of Inconel625 alloy: The microstructure of the alloy in solid solution state is austenite matrix and a small amount of TiN, NbC, and M6C phases. After long-term aging at 650-900 °C, the precipitated phases are γ", δ, M23C6 and M6C. After long-term aging at 650～700℃, γ” is mainly precipitated, which significantly increases the strength of the alloy at room temperature and high temperature, and reduces the plasticity, but still maintains a high level; after aging at 780～850℃, mainly precipitates δ phase, although the strength increased, but the plasticity of the alloy decreased more. After aging at 900 °C, there is only a small amount of precipitates, so the mechanical properties are similar to those of the solid solution state. The δ phase is an orthorhombic structure of flake Ni3Nb, and exists in acicular Widmanrite [1,7].

5. Process performance and requirements of Inconel625 (NO6625) superalloy:

1. Forming properties of Inconel625:
The cold and hot forming properties of the alloy are good. The ingot forging heating temperature is 1120℃, the forging temperature is not lower than 1030℃, and the stop forging temperature is not lower than 930℃; during die forging, the final deformation should be not less than 15% to 20%. The rolling heating temperature is 1120-1160 °C, the rolling temperature is not lower than 1050 °C, and the stopping temperature is not lower than 930 °C. The quenching temperature of intermediate and finished products is 1100℃±10℃[1,8].

2. Inconel625 welding performance:
The alloy has good welding performance. It can be used for argon arc welding with tungsten electrode or this alloy as filler material under protective atmosphere, and can also be used for brazing connection and resistance seam welding.

3. Heat treatment process of Inconel625 parts:
Stress relief: 900℃; Annealing: 930～1040℃, 1h; Solution treatment: 1090～1200℃, air cooling or water cooling. When the alloy is working at not higher than 650℃, the material in hot rolled, cold rolled or annealed state can be used according to the requirements. When the working temperature is above 650°C, the annealing process can be used for parts that require better fatigue performance and tensile strength, and the solution treatment can be used for parts that require better creep and durability properties.

4. Inconel625 surface treatment process: when removing the oxide scale on the surface of the alloy, firstly alkali wash, and then pickle in nitric acid-hydrofluoric acid-water solution.

5. Inconel625 cutting and grinding performance:
Carbide or high-speed steel tools should be used. The cutting tool used should have a positive rake angle. Water-based coolant is recommended for high-speed cutting, and thicker coolant is recommended for low-speed cutting.