Most of the components in the nuclear and conventional islands of PWR nuclear power plants are made of steel. Except for the nuclear fuel cladding, control rod drive mechanism and steam generator heat transfer tube and other components are made of zirconium alloy and nickel-based alloy, the rest of the equipment is made of steel materials.
1. Loop main pipe.
Under the normal, abnormal, accident and test conditions of nuclear power plants, it is an important barrier to prevent the leakage of nuclear reaction fission products to the containment. Therefore, the main nuclear power pipeline must be able to withstand high temperatures, high pressures and corrosion. The primary main pipeline of the AP1000 nuclear power plant is made of monolithically forged 316LN austenitic stainless steel.
2. Reactor pressure vessel.
The reactor pressure vessel operates under harsh conditions such as high temperature, high pressure, fluid erosion and corrosion, and strong neutron irradiation, and its design life is not less than 40 years and cannot be replaced. The pressure vessel material must meet the following special requirements: high enough purity, density and uniformity, appropriate strength and good toughness, excellent irradiation embrittlement resistance and aging resistance, excellent weldability, cold and hot processing performance and excellent corrosion resistance. A508-3 is currently the material of the pressure vessel of large pressurized water reactors.
inconel
Commercial Grades:inconel600 nickel-based superalloy
U.S. Grade:N06600 nickel-based superalloy
Chinese grade: GH600 GH3600
1. Overview of Inconel 600 (N06600) nickel-based alloys:
INCONEL600 is an early developed nickel-chromium-iron-based solution strengthened alloy, which has good high temperature corrosion resistance and oxidation resistance, excellent cold and hot processing and welding process performance, and has satisfactory thermal strength and high plasticity below 700. The alloy can be strengthened by cold working, and can also be connected by resistance welding, fusion welding or brazing, and can be used for cold-rolled sheets, hot-rolled thick plates, strips, wires, bars, round cakes, ring blanks, ring forgings, etc., which are suitable for making oxidation resistant parts with low loads below 1100.
1. Material grade: INCONEL 600 (N06600) nickel-based alloy.
2. Inconel600 similar grades: Inconel, GH600, GH3600 (China).
3. Chemical composition of Inconel600: See Table 1-1.
Table 1-1
Note: 1 Aerospace materials standard BZ-44-9003B-0 stipulates (c) 010%,ωp)≤0.020%,ωnb)≤1.00%。
2 Fugaoxin 1995-13 standard provisions (p) 0025%,ωnb)≤1.00%。
4. Heat treatment system: plate: 1010 1050, 3 5min mm, air cooling; Strip: 1010 10, air-cooled; Wire: 1065 10, air cooled. The inspection test of bars and rings has been treated by 1010 10 and air-cooled solid solution.
5. Varieties and specifications: various specifications of plates, bars, forgings, strips, wires, round cakes, ring blanks, ring forgings. The bar is in a forged state, surface polished or polished**; Round cakes and ring blanks in a forged state**; Rings in a solid solution state**; After the plate is solved and alkali pickled, straightened and trimmed**; Strip is delivered by cold rolling, solution and descaling; The wire is delivered in solution pickled disc or straight strip shape, solution straight strip fine polished condition.
6. Smelting and casting process: the alloy is smelted by one of the following processes: (1) non-vacuum induction smelting plus electroslag remelting; (2) Electric arc furnace smelting and electroslag remelting; (3) Vacuum melting.
7. Application overview and special requirements: The alloy has mature experience in foreign use, and has been made into aerospace engine parts in China, and has been used in aviation through flight tests.
2. Physical and chemical properties of Inconel 600 (N06600) nickel-based alloy:
1. Thermal performance of INCONEL600:
1) Melting temperature range: 1370 1430 [1].
2) Thermal conductivity: see Table 2-1.
Table 2-1
3) Specific heat capacity: see Figure 2-1.
4) Linear expansion coefficient: see Table 2-2.
2. Inconel600 density: =843g/cm3。
3. Electrical properties of inconel600: the resistivity is shown in Figure 2-2.
Table 2-
4. Inconel600 magnetic properties: the alloy is non-magnetic.
5. Chemical properties of Inconel600: antioxidant performance: the oxidation rate of 100h in air medium is shown in Table 2-3.
Table
3. Mechanical properties of Inconel 600 (N06600) nickel-based alloy:
Performance specified in the Inconel600 technical standard: see Table 3-1.
Table
* The state plate should be subjected to a bending test at room temperature, the diameter of the mandrel is equal to the thickness of the product multiplied by the bending coefficient in Table 3-2, the bending axis should be parallel to the rolling direction, after bending 180°, check under magnification 20 times, and there shall be no cracks.
Table
4. Microstructure of INCONEL 600 (N06600) nickel-based alloy:
1. Inconel600 phase change temperature:
2. Inconel600 time-temperature-tissue transition curve:
3. Microstructure of Inconel600 alloy: after 2h of 1120 treatment, only Tin nitride and CR7C3 carbide are available, and after 1500h of long-term aging at 870, Cr7C3 and Tin are still in the microstructure, indicating that the microstructure of the alloy is stable.
5. Process performance and requirements of INCONEL 600 (N06600) nickel-based alloy:
1. Inconel600 forming performance: the alloy has good hot working properties, and the heating temperature of ingot forging is 1110 1140; The final forging temperature is not less than 950, the slab rolling heating temperature is 1130 1170, and the finishing rolling heating temperature is 1090 1130. The solution treatment temperature of the finished product is 1010 1050.
2. Inconel600 welding performance: the alloy has good welding performance, and can be connected by various methods such as arc welding, argon arc welding, resistance welding and brazing, and large or complex welded structural parts should be annealed at 870 for 1h after fusion welding to eliminate welding stress.
3. Inconel600 parts heat treatment process: The heat treatment process of parts should be carried out according to the heat treatment system of the corresponding material standards. The annealing of sheet and strip parts should be carried out in a protective atmosphere.
6. Inconel600 (N06600) nickel-based alloy variety specifications and ** status:
1. Variety classification: special alloys can produce various specifications of Inconel600 seamless pipes, Inconel600 steel plates, Inconel600 round bars, Inconel600 forgings, Inconel600 flanges, Inconel600 rings, Inconel600 welded pipes, Inconel600 steel strips, Inconel600 wires and Inconel600 supporting welding consumables.
2. Delivery status: seamless tube: solid solution + acid white, length can be fixed; Plates: solid solution, pickling, trimming; Welded pipe: solid solution acid white + RT% flaw detection, forgings: annealing + turning light; The bar is in a forged state, surface polished or polished**; The strip is delivered by cold rolling, solution soft state, and descaling; The wire is delivered in solution pickled disc or straight strip shape, solution straight strip fine polished condition.