Nickel chromium alloy for sealing face of nuclear power valve

Abstract

The invention discloses a nickel chromium alloy for a sealing face of a nuclear power valve. The nickel chromium alloy comprises the following components in percentage by weight: 26.0-28.0 percent of chrome, 2.0-2.5 percent of silicon, 1.1-1.3 percent of boron, 4.5-5.5 percent of molybdenum, 3.0-4.0 percent of tungsten, 0.9-1.1 percent of carbon and the balance of nickel. Meanwhile, a coating layer is prepared by a laser cladding technology so as to obtain a sealing face coating layer of a nickel-based alloy nuclear power valve, which has the following relevant parameters: the rigidity is HRC 42-46 which is slightly higher than HRC39-43 of a Stellite-6 cobalt-based alloy coating layer; the tissue grain fineness number of the coating layer is 11-12 grades which is superior to 9-10 grades of a general plasma jet welding layer and 8-9 grades of a flame resurfacing welding layer; and the width of a combination band of the coating layer and a basal body is 10-30 micrometers which is superior to 80-120 micrometers of a plasma jet welding combination band and 200-300 micrometers of a flame resurfacing welding combination band.

Description

technical field

[0001] The invention relates to a nickel-chromium alloy, in particular to a cobalt-free nickel-chromium alloy used as a strengthening material for the sealing surface of nuclear power valves. Background technique

[0002] The service conditions of nuclear power valve sealing surfaces are quite harsh, requiring high wear resistance, corrosion resistance, and high temperature resistance. At present, the surfacing welding materials for the sealing surface of nuclear valves are generally cobalt-based alloys, such as Stellite 6 or Stellite 21. Cobalt-based alloys have good high temperature performance, excellent low friction and anti-wear properties, excellent hot corrosion resistance and thermal fatigue resistance, especially in the hot state with excellent scratch resistance, so they are often used for surfacing welding The service conditions are relatively harsh, and the valve sealing surface with high anti-wear and anti-corrosion performance requirements. Ho...

Examples

Embodiment 1

[0036] (1) The percentage by weight of the nickel-chromium alloy powder mixture composition for preparing the sealing surface coating of nuclear power valves is: chromium: 28.0%, silicon: 2.5%, boron: 1.3%, molybdenum: 5.5%, tungsten: 4.0%, carbon: 1.1 %, the rest is nickel; the above powders are mixed by mechanical mixing method, the powder particle size is 200-300 mesh, and baked and dried;

[0037] (2) On the sealing surface of nuclear power valves with stainless steel substrates, the power used is 10 4 W / cm 2 The laser irradiates the surface of the substrate to form a local molten pool, and the mixed powder is sent into the molten pool by the synchronous powder feeding method, and the inert gas nitrogen is used as the delivery gas. When the laser acts on the substrate and the mixed powder, the solvent is protected by the inert gas nitrogen pool surface to avoid oxidation; the laser is CO 2 Laser, the scanning speed of the laser beam is 3mm / s, the spot size is 3mm, and th...

Embodiment 2

[0040] (1) The percentage by weight of the nickel-chromium alloy powder mixture composition for preparing the sealing surface coating of nuclear power valves is: chromium: 28.0%, silicon: 2.5%, boron: 1.3%, molybdenum: 5.5%, tungsten: 4.0%, carbon: 1.1 %, the rest is nickel; the above-mentioned powders are mixed by mechanical mixing method, and the particle size of the powder is 200-300 mesh;

[0041] (2) Use ethanol to dissolve 2123 phenolic resin material as an adhesive, mix it with the above powder mixture, and coat a ring-shaped pre-coating with an average diameter of 50mm, a width of 5mm, and a thickness of 2.5mm on the sealing surface of the nuclear power valve of the stainless steel substrate , and baked to dry;

[0042] (3) Use a power of 10 4 W / cm 2 The laser irradiates the coated annular pre-laying coating, and at the same time blows inert gas to the molten pool to avoid oxidation of the molten pool surface; the laser uses CO 2 Laser, the laser beam scanning speed i...

Embodiment 3

[0045] The specific steps are the same as in Example 1, the difference is that the weight percentages of the powder mixture components described in step (1) are adjusted to chromium: 26.0%, silicon: 2.0%, boron: 1.1%, aluminum: 4.5%, tungsten: 3.0% , Carbon: 0.9%, the rest is nickel. A coating with a hardness of HRC42 is obtained.

technical field

[0001] The invention relates to a nickel-chromium alloy, in particular to a cobalt-free nickel-chromium alloy used as a strengthening material for the sealing surface of nuclear power valves. Background technique

[0002] The service conditions of nuclear power valve sealing surfaces are quite harsh, requiring high wear resistance, corrosion resistance, and high temperature resistance. At present, the surfacing welding materials for the sealing surface of nuclear valves are generally cobalt-based alloys, such as Stellite 6 or Stellite 21. Cobalt-based alloys have good high temperature performance, excellent low friction and anti-wear properties, excellent hot corrosion resistance and thermal fatigue resistance, especially in the hot state with excellent scratch resistance, so they are often used for surfacing welding The service conditions are relatively harsh, and the valve sealing surface with high anti-wear and anti-corrosion performance requirements. Ho...

Examples

Embodiment 1

[0036] (1) The percentage by weight of the nickel-chromium alloy powder mixture composition for preparing the sealing surface coating of nuclear power valves is: chromium: 28.0%, silicon: 2.5%, boron: 1.3%, molybdenum: 5.5%, tungsten: 4.0%, carbon: 1.1 %, the rest is nickel; the above powders are mixed by mechanical mixing method, the powder particle size is 200-300 mesh, and baked and dried;

[0037] (2) On the sealing surface of nuclear power valves with stainless steel substrates, the power used is 10 4 W / cm 2 The laser irradiates the surface of the substrate to form a local molten pool, and the mixed powder is sent into the molten pool by the synchronous powder feeding method, and the inert gas nitrogen is used as the delivery gas. When the laser acts on the substrate and the mixed powder, the solvent is protected by the inert gas nitrogen pool surface to avoid oxidation; the laser is CO 2 Laser, the scanning speed of the laser beam is 3mm / s, the spot size is 3mm, and th...

Embodiment 2

[0040] (1) The percentage by weight of the nickel-chromium alloy powder mixture composition for preparing the sealing surface coating of nuclear power valves is: chromium: 28.0%, silicon: 2.5%, boron: 1.3%, molybdenum: 5.5%, tungsten: 4.0%, carbon: 1.1 %, the rest is nickel; the above-mentioned powders are mixed by mechanical mixing method, and the particle size of the powder is 200-300 mesh;

[0041] (2) Use ethanol to dissolve 2123 phenolic resin material as an adhesive, mix it with the above powder mixture, and coat a ring-shaped pre-coating with an average diameter of 50mm, a width of 5mm, and a thickness of 2.5mm on the sealing surface of the nuclear power valve of the stainless steel substrate , and baked to dry;

[0042] (3) Use a power of 10 4 W / cm 2 The laser irradiates the coated annular pre-laying coating, and at the same time blows inert gas to the molten pool to avoid oxidation of the molten pool surface; the laser uses CO 2 Laser, the laser beam scanning speed i...

Embodiment 3

[0045] The specific steps are the same as in Example 1, the difference is that the weight percentages of the powder mixture components described in step (1) are adjusted to chromium: 26.0%, silicon: 2.0%, boron: 1.1%, aluminum: 4.5%, tungsten: 3.0% , Carbon: 0.9%, the rest is nickel. A coating with a hardness of HRC42 is obtained.