CN114131242A - Alloy material for surfacing layer of sealing surface of valve seat and welding process of alloy material - Google Patents
Alloy material for surfacing layer of sealing surface of valve seat and welding process of alloy material Download PDFInfo
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- CN114131242A CN114131242A CN202111599490.8A CN202111599490A CN114131242A CN 114131242 A CN114131242 A CN 114131242A CN 202111599490 A CN202111599490 A CN 202111599490A CN 114131242 A CN114131242 A CN 114131242A
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K35/00—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting
- B23K35/22—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by the composition or nature of the material
- B23K35/24—Selection of soldering or welding materials proper
- B23K35/30—Selection of soldering or welding materials proper with the principal constituent melting at less than 1550 degrees C
- B23K35/3033—Ni as the principal constituent
- B23K35/304—Ni as the principal constituent with Cr as the next major constituent
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K10/00—Welding or cutting by means of a plasma
- B23K10/02—Plasma welding
- B23K10/027—Welding for purposes other than joining, e.g. build-up welding
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K26/00—Working by laser beam, e.g. welding, cutting or boring
- B23K26/34—Laser welding for purposes other than joining
- B23K26/342—Build-up welding
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K26/00—Working by laser beam, e.g. welding, cutting or boring
- B23K26/60—Preliminary treatment
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K37/00—Auxiliary devices or processes, not specially adapted to a procedure covered by only one of the preceding main groups
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K9/00—Arc welding or cutting
- B23K9/04—Welding for other purposes than joining, e.g. built-up welding
- B23K9/042—Built-up welding on planar surfaces
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K9/00—Arc welding or cutting
- B23K9/16—Arc welding or cutting making use of shielding gas
- B23K9/167—Arc welding or cutting making use of shielding gas and of a non-consumable electrode
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K9/00—Arc welding or cutting
- B23K9/235—Preliminary treatment
Abstract
The invention discloses an alloy material for a surfacing layer of a sealing surface of a valve seat, which comprises a nickel-based alloy and a cobalt-based alloy, wherein the mass ratio of the nickel-based alloy to the cobalt-based alloy is 1: 1-5. The alloy disclosed by the invention takes the nickel-based alloy as the buffer layer, the nickel-based alloy is firstly overlaid on the base body of the sealing surface of the valve seat, and then the cobalt-based alloy is overlaid, so that the advantages/characteristics of the two materials can be well combined, the overlaying layer of the sealing surface can simultaneously meet the comprehensive performances of wear resistance, impact resistance, corrosion resistance, high temperature resistance, scratch resistance, oxidation resistance, cracking resistance and the like, and the sealing surface of the valve seat can be fixed with gold soup.
Description
Technical Field
The invention relates to the technical field of alloy materials, in particular to an alloy material for a surfacing layer of a sealing surface of a valve seat and a welding process thereof.
Background
The valve seat occupies a considerable proportion in mechanical products, and particularly plays a key role in industries such as nuclear power, thermal power, petrifaction and metallurgy, and the dosage is very large. With the progress of science and technology, valves used in various valve seat industries at home and abroad are developed in the direction of high parameters such as large size, high temperature and high pressure resistance, strong corrosion and friction resistance, high reliability and long service life in recent years.
The high parameter valve seat is used in a rather harsh condition and the required safety and reliability are very high. According to statistics, the most common fault types of typical valve seats in the industries of nuclear power, thermal power and the like are internal leakage, external leakage and sealing surface damage. The quality of the sealing surface of the valve seat, including comprehensive performances of wear resistance, impact resistance, corrosion resistance, high temperature resistance, scratch resistance, oxidation resistance and the like, directly influences the reliability and the service life of the valve seat.
The F92 steel is used as an excellent high-temperature heat-resistant steel and widely applied to supercritical and ultra-supercritical power station boilers, and because F92 is imported from foreign countries, and a valve seat is used as a key control piece of an ultra-supercritical unit, higher requirements on the welding mode and welding parameters of the ultra-supercritical unit are required. However, F92 is not suitable as a sealing surface, and has poor wear resistance and cavitation resistance, and is not resistant to scouring and scraping. The FB2 rotor steel is a novel 9% Cr martensitic heat-resistant steel developed in the European COST project, the components are 0.13% C-9.32% Cr-1.5% Mo-1% Co-0.0085% B, the corresponding cast steel is CB2, and the B element content is higher. The microscopic structure and mechanical property test research is carried out on 500kg test FB2 steel, and the result shows that the creep rupture strength of FB2 after 625 ℃/100000 aging reaches 100MPa, and the CB2 is 85 MPa.
Although F92 and FB2 have the excellent performance, the sealing surface of the valve seat of the steam turbine still cannot meet the requirement of being used as the sealing surface of the valve seat, and the sealing surface at the valve seat of the steam turbine is always in a steam atmosphere in service and directly receives the impact, heat transfer, cavitation and other effects of working steam. In the prior art, the material of the overlaying layer on the sealing surface of the valve seat is tungsten-chromium-cobalt-based alloy powder or welding wire of Stellite No. 6 (Stellite, Stellite No. 6#) which is commonly used in the prior art, and the tungsten-chromium-cobalt-based alloy powder or the welding wire is used as a turbine blade, a forged piece and a cast piece on a nozzle blade of a gas turbine engine or as a wear-resistant overlaying material key valve component and is used for energy sources and key components of a seawater desalination plant. Although the Stellite alloy as a high-temperature wear-resistant layer is used on a steel substrate through multi-pass surfacing, the Stellite alloy has the advantages of low friction and wear resistance, excellent hot corrosion resistance and thermal fatigue resistance, and particularly has excellent scratch resistance in a hot state, the Stellite alloy has high hardness, high wear resistance and high strength, and the cracking and the falling of the Stellite surfacing layer are one of the key defects generated in power generation equipment under the service working condition, and similar conditions often occur, so that the sealing surface of a valve seat becomes a vulnerable part, the valve seat needs to be repaired or replaced periodically, and the service life of the product is seriously influenced. In addition, cobalt-based alloys exhibit a significant drawback for valve seats operating in a nuclear environment: co-59 in the wear and corrosion fragments of the cobalt-based alloy is excited to form a Co-60 isotope after being irradiated by neutrons, and the Co-60 is a strong radioactive source with extremely long half life, so that the overhaul time is increased and the threat to maintenance personnel is caused during shutdown and overhaul, and the difficulty and the cost of nuclear fuel shielding are greatly increased. In addition, the cobalt-based alloy is expensive in price and the use of the cobalt-based alloy is limited due to the shortage of cobalt resources in China.
Disclosure of Invention
Aiming at the defects in the prior art, the invention aims to provide an alloy material for a surfacing layer of a sealing surface of a valve seat, so as to solve the problem that the common tungsten-chromium-cobalt-based alloy for the surfacing layer of the sealing surface of the valve seat in the prior art often cracks, falls off and loses efficacy in the service process.
In order to solve the technical problems, the invention adopts the following technical scheme:
the alloy material for the surfacing layer of the sealing surface of the valve seat comprises a nickel-based alloy and a cobalt-based alloy, wherein the mass ratio of the nickel-based alloy to the cobalt-based alloy is 1: 1-5;
the nickel-based alloy comprises the following components in percentage by mass: 20-23% of chromium; 8-10% of molybdenum; 3.15 to 4.15 percent of niobium; iron < 5%; aluminum < 0.4%; titanium < 0.4%; carbon < 0.1%; manganese < 0.5%; silicon < 0.5%; cobalt is less than 1%; phosphorus < 0.015%; sulfur < 0.015%; the balance being nickel;
the cobalt-based alloy comprises the following components in percentage by mass: 28-32% of chromium; molybdenum < 1.5%; iron < 3%; carbon is 0.9-1.4%; manganese is less than 2%; silicon < 1.5%; nickel is less than 3%; phosphorus < 0.015%; sulfur < 0.015%; 3.5-5.5% of tungsten; the balance being cobalt.
The invention also provides a welding process for the surfacing layer of the sealing surface of the valve seat, which adopts the alloy as the surfacing layer and carries out welding by the following method:
firstly, polishing and cleaning a base body of the sealing surface of the valve seat, then overlaying a nickel-based alloy on the base body as a buffer layer, and overlaying a cobalt-based alloy to obtain the sealing surface of the valve seat with an overlaying layer.
Compared with the prior art, the invention has the following beneficial effects:
1. according to the invention, after research on the base material of the sealing surface of the valve seat, the nickel-based alloy is firstly overlaid on the base body of the sealing surface of the valve seat and then the cobalt-based alloy is overlaid when the nickel-based alloy is used as a buffer layer, so that the advantages/characteristics of the two materials can be well combined, the overlaying layer of the sealing surface can simultaneously meet the comprehensive performances of wear resistance, impact resistance, corrosion resistance, high temperature resistance, scratch resistance, oxidation resistance, crack resistance and the like, the problem of failure such as cracking, falling and the like easily occurring in the service process is reduced, and the sealing surface of the valve seat is fixed in gold soup.
2. The invention adopts argon tungsten arc welding (GTAW or TIG), Shielded Metal Arc Welding (SMAW), plasma arc hot spray welding (PAW), laser beam deposition overlaying (LBW) and Submerged Arc Welding (SAW) for overlaying, all can achieve the technical effect of the invention, but after researching a plurality of welding methods, the sealing surface of the valve seat after overlaying by the PAW process has more excellent wear resistance, and the sealing surface of the valve seat after overlaying by the TIG and LBW processes also has better performance than the sealing surface of the existing valve seat.
Drawings
FIG. 1 is an optical microscope photograph of a nickel-based alloy material (lower portion) and a cobalt-based alloy material (upper portion) deposited on a sealing surface of a valve seat in accordance with example 2.
Fig. 2 is an optical microscope image of the base material (lower part) and the nickel-based alloy material (upper part) of the weld deposit of the sealing surface of the valve seat according to example 2.
In the figure: the material comprises a cobalt-based material 1, a nickel-based material 2 and a base material 3.
Detailed Description
The invention will be further explained with reference to the drawings and examples.
Alloy material for surfacing layer of sealing surface of valve seat
The alloy material comprises a nickel-based alloy and a cobalt-based alloy, wherein the mass ratio of the nickel-based alloy to the cobalt-based alloy is 1: 1-5;
the nickel-based alloy comprises the following components in percentage by mass: 20-23% of chromium; 8-10% of molybdenum; 3.15 to 4.15 percent of niobium; iron < 5%; aluminum < 0.4%; titanium < 0.4%; carbon < 0.1%; manganese < 0.5%; silicon < 0.5%; cobalt is less than 1%; phosphorus < 0.015%; sulfur < 0.015%; the balance being nickel;
the cobalt-based alloy comprises the following components in percentage by mass: 28-32% of chromium; molybdenum < 1.5%; iron < 3%; carbon is 0.9-1.4%; manganese is less than 2%; silicon < 1.5%; nickel is less than 3%; phosphorus < 0.015%; sulfur < 0.015%; 3.5-5.5% of tungsten; the balance being cobalt. Wherein the nickel alloy is positioned as a buffer layer under the cobalt-based alloy.
In the research of the base material of the sealing surface of the valve seat, the invention discovers that if the tungsten-chromium-cobalt-based alloy material is separately overlaid on the base material of the sealing surface of the valve seat, although the base material can meet the use requirements on the performance requirements of high temperature resistance, impact resistance, corrosion resistance, wear resistance and the like, the material is the tungsten-chromium-cobalt-based alloy with about 1% of carbon, and the microstructure consisting of a carbide particle network can be generated in a softer matrix due to the higher carbon content, depending on the welding method and the dilution rate. Because of the existence of carbide network, the wear resistance of the alloy is better, but a build-up welding layer is easy to crack, so that the problem of poor crack resistance exists in the cobalt-based alloy which is built up separately. Meanwhile, if the nickel-based alloy material is separately overlaid on the base material of the sealing surface of the valve seat, although the use requirements can be met on the performance requirements of high temperature resistance, corrosion resistance, wear resistance, crack resistance and the like, the nickel-based alloy material is a Ni-Cr-based solid solution strengthening type deformation high-temperature alloy, and the solid solution strengthening type nickel-based deformation high-temperature alloy taking molybdenum and niobium as main strengthening elements is subjected to an age hardening phenomenon after long-term use at 550-700 ℃, so that the wear resistance is better, the plasticity, the ductility and the fatigue resistance are good below 980 ℃, and under the action of a certain load, the nickel-based alloy material is easy to generate larger deformation and cannot resist impact, so the problem of poor impact resistance still exists in the separate overlaying.
Therefore, the invention considers how to combine the advantages and the characteristics of the two alloy materials, and after the two alloy materials are deeply researched, the invention discovers that if the nickel-based alloy is used as a buffer layer, the nickel-based alloy is firstly overlaid on the base body of the sealing surface of the valve seat, and then the cobalt-based alloy is overlaid, the obtained overlaying layer of the sealing surface obtains better comprehensive performance, the advantages/characteristics of the two materials can be well combined, so that the overlaying layer of the sealing surface meets the comprehensive performances of wear resistance, impact resistance, corrosion resistance, high temperature resistance, scratch resistance, oxidation resistance, crack resistance and the like at the same time, the problem of failure such as cracking, falling and the like easily occurs in the service process is reduced, and the sealing surface of the valve seat is fixed with the gold soup.
Table 1 table of compositions of nickel-base alloy materials selected according to the present invention
| Composition (I) | Range | Example 1 | Example 2 | Example 3 | Example 4 | Example 5 |
| Chromium Cr | 20-23％ | 20.89％ | 23.0％ | 20.89％ | 21.5％ | 22.0％ |
| Molybdenum Mo | 8-10％ | 8.49％ | 10.0％ | 8.49％ | 9.0％ | 9.0％ |
| Niobium Nb | 3.15-4.15％ | 3.15％ | 3.15％ | 3.69％ | 3.6％ | 3.56％ |
| Fe | <5％ | 4.67％ | 4.5％ | 2.5％ | 2.5％ | 2.74％ |
| Aluminum Al | <0.4％ | 0.17％ | 0.1％ | 0.17％ | 0.2％ | 0.2％ |
| Titanium Ti | <0.4％ | 0.18％ | 0.34％ | 0.10％ | 0.2％ | 0.1％ |
| Carbon C | <0.1％ | 0.03％ | 0.05％ | 0.058％ | 0.05％ | 0.058％ |
| Mn manganese | <0.5％ | 0.08％ | 0.45％ | 0.08％ | 0.08％ | 0.01％ |
| Silicon Si | <0.5％ | 0.12％ | 0.45％ | 0.12％ | 0.48％ | 0.04％ |
| Cobalt Co | <1％ | 0.03％ | 0.03％ | 0.1％ | 0.13％ | 0.5％ |
| Phosphorus P | <0.015％ | 0.005％ | 0.015％ | 0.005％ | 0.005％ | 0.005％ |
| Sulfur S | <0.015％ | 0.0004％ | 0.015％ | 0.00044％ | 0.0004％ | 0.0004％ |
| Ni | Balance of | Balance of | Balance of | Balance of | Balance of | Balance of |
TABLE 2 composition table of cobalt-based alloy materials selected according to the invention
| Composition (I) | Range | Example 1 | Example 2 | Example 3 | Example 4 | Example 5 |
| Chromium Cr | 28-32％ | 29.0％ | 29.5％ | 28.0％ | 31.0％ | 30.5％ |
| Molybdenum Mo | <1.5％ | 1.0％ | 0.67％ | 1.4％ | 0.67％ | 1.2％ |
| Fe | <3％ | 2.0％ | 2.0％ | 2.0％ | 2.5％ | 1.8％ |
| Carbon C | 0.9-1.4％ | 1.15％ | 1.2％ | 1.0％ | 1.3％ | 1.2％ |
| Mn manganese | <2％ | 0.5％ | 1.08％ | 0.5％ | 1.2％ | 1.2％ |
| Silicon Si | <1.5％ | 1.1％ | 1.0％ | 1.1％ | 0.5％ | 0.5％ |
| Ni | <3％ | 2.3％ | 3％ | 2.5％ | 1.8％ | 1.5％ |
| Phosphorus P | <0.015％ | 0.005％ | 0.005％ | 0.005％ | 0.005％ | 0.005％ |
| Sulfur S | <0.015％ | 0.005％ | 0.005％ | 0.005％ | 0.005％ | 0.005％ |
| Tungsten W | 3.5-5.5％ | 4.0％ | 4.5％ | 4.0％ | 5.0％ | 3.5％ |
| Cobalt Co | Balance of | Balance of | Balance of | Balance of | Balance of | Balance of |
TABLE 3 build-up welding ratio of Ni-base alloy and Co-base alloy in the invention
| Examples | Build-up welding material | Build-up welding proportioning |
| 1 | Nickel-based alloy: cobalt-based alloy | 1:1 |
| 2 | Nickel-based alloy: cobalt-based alloy | 1:2 |
| 3 | Nickel-based alloy: cobalt-based alloy | 1:3 |
| 4 | Nickel-based alloy: cobalt-based alloy | 1:4 |
| 5 | Nickel-based alloy: cobalt-based alloy | 1:5 |
The surfacing ratio is 1:2, and means that 1 layer of nickel-based alloy is firstly surfaced and then 2 layers of nickel-based alloy are surfaced during surfacing, and when the surfacing ratio is distributed to pass, 1/2/3/4 … … passes of nickel-based alloy can be surfaced and then 2/4/6/8 … … passes of cobalt-based alloy can be surfaced. In actual operation, the number of passes is selected and determined according to the model specification of the sealing surface of the valve seat, if the sealing surface of the small valve seat is adopted, the number of passes is relatively small (generally 1-4 passes are adopted), and if the sealing surface of the large valve seat is adopted, the number of passes is relatively large (generally more than 10 passes are adopted). The model specification of the sealing surface of the valve seat is in certain relation with the type of the steam turbine (namely the steam temperature of the steam turbine, wherein the steam temperature refers to the new steam rated temperature at the inlet of a main steam valve of the steam turbine), the higher the power grade parameter of the steam turbine is, the larger the model specification of the sealing surface of the valve seat is, but small sealing surface parts also exist in the steam turbine with high power grade. Therefore, the number of passes is comprehensively determined according to the actual working environment and the structure of the steam turbine.
Welding process for surfacing layer of sealing surface of valve seat
Firstly, polishing and cleaning a base body of a sealing surface of the valve seat, then overlaying a nickel-based alloy on the base body as a buffer layer, and overlaying a cobalt-based alloy to obtain the valve seat with an overlaying layer sealing surface.
In examples 1 to 5, nickel-based alloy material components shown in table 1 and cobalt-based alloy material components shown in table 2 were respectively used, and according to the surfacing mixture ratio shown in table 3, inert gas tungsten arc welding (GTAW, also referred to as TIG), plasma arc thermal welding (PAW), and laser beam deposition surfacing (LBW), nickel-based alloy and cobalt-based alloy surfacing was performed on a simulated ring piece of a turbine valve seat sealing surface of a steam turbine of Φ 20 × 3 cm.
The present invention will be described in further detail with reference to examples 1 to 5.
1. Argon tungsten arc welding
The nickel-based alloy and the cobalt-based alloy for surfacing are applied to welding wires.
(1) Firstly, polishing and cleaning a base material of a sealing surface of a valve seat;
(2) forming a V-shaped groove on a base material of the ring piece on the sealing surface of the valve seat, overlaying the nickel-based alloy, connecting the polarity of a power supply in a direct current reverse mode, wherein the welding current is 200-300A, the welding voltage is 9-15V, the welding speed is 70-95 mm/min, the interlayer temperature is 100 ℃, and overlaying of the nickel-based alloy is completed according to the proportion, the number and the pass of overlaying;
(3) and (2) surfacing the cobalt-based alloy, wherein the polarity of a power supply is in direct current positive connection, the welding current is 200-300A, the welding voltage is 9-15V, the welding speed is 70-95 mm/min, the preheating temperature before welding is greater than 200 ℃, the post-heating temperature is controlled to be 430-480 ℃, the interlayer temperature is controlled to be 300-350 ℃, and surfacing of the cobalt-based alloy is completed according to surfacing proportion, layers and passes.
Table 4 shows the welding process parameters of the argon tungsten-arc welding surfacing of the nickel-based alloy and the cobalt-based alloy in examples 1-5
2. Plasma arc thermal spray welding
The nickel-based alloy and the cobalt-based alloy for the overlay welding are applied with alloy powder.
(1) Firstly, polishing and cleaning a base material of a sealing surface of a valve seat, and then, forming a V-shaped groove on the base material of a ring piece of the sealing surface of the valve seat.
(2) Surfacing of a nickel-based alloy: the polarity of the power supply adopts direct current reverse connection, and one or more layers of nickel-based alloys are subjected to surfacing on the surface of the sealing surface matrix according to surfacing proportion to serve as buffer layers; in the step (2), when the first layer of the nickel-based alloy is subjected to surfacing welding, the welding current is 162-200A, the welding voltage is 27-33V, the welding speed is 80-110 mm/min, the powder feeding speed is 20-33 g/min, the ion arc gas is argon, the flow rate is 180-200L/min, the protective gas is argon, the flow rate is 540-600L/min, the powder feeding gas is argon, and the flow rate is 380-420L/min; when a second layer or more (if a plurality of layers are selected) is overlaid on the nickel-based alloy, the welding current is 162-198A, the welding voltage is 27-33V, the welding speed is 80-110 mm/min, the powder feeding speed is 20-33 g/min, the ion arc gas is argon, the flow rate is 180-200L/min, the protective gas is argon, the flow rate is 540-600L/min, the powder feeding gas is argon, the flow rate is 380-420L/min, the preheating temperature before welding is 90-110 ℃, and the interlayer temperature is controlled at 140-160 ℃.
(3) Surfacing welding a cobalt-based alloy; and the polarity of the power supply adopts direct current positive connection, and one or more layers of cobalt-based alloy are subjected to surfacing on the buffer layer according to the surfacing proportion. In the step (3), when a first layer of cobalt-based alloy is overlaid, the welding current is 162-200A, the welding voltage is 27-33V, the welding speed is 70-101 mm/min, the powder feeding speed is 33-40 g/min, the ion arc gas is argon, the flow rate is 170-190L/min, the shielding gas is argon, the flow rate is 540-660L/min, the powder feeding gas is argon, and the flow rate is 380-420L/min; when the second layer and above of the cobalt-based alloy are subjected to surfacing welding, the welding current is 162-198A, the welding voltage is 27-33V, the welding speed is 70-101 mm/min, the powder feeding speed is 33-40 g/min, the ion arc gas is argon, the flow rate is 170-190L/min, the shielding gas is argon, the flow rate is 540-660L/min, the powder feeding gas is argon, and the flow rate is 380-420L/min; the preheating temperature before welding is more than 200 ℃, the post-heating temperature is controlled to be 430-480 ℃, and the interlayer temperature is controlled to be 300-350 ℃.
TABLE 5 welding Process parameters for plasma arc thermal spray overlay welding of nickel-based and cobalt-based alloys of examples 1-5
3. Laser beam deposition build-up welding
The nickel-based alloy and the cobalt-based alloy for the overlay welding are applied with alloy powder.
(1) Firstly, polishing and cleaning a base material of a sealing surface of a valve seat, and then, forming a V-shaped groove on the base material of a ring piece of the sealing surface of the valve seat.
(2) Surfacing of a nickel-based alloy: the laser scanning speed is 8mm/s, the laser power is 1300W, the powder feeding speed is 10g/min, the coaxial gas flow is 16L/min, the interlayer temperature is controlled to be 90-110 ℃, and one or more layers of nickel-based alloys are overlaid on the surface of the sealing surface matrix according to the overlaying ratio to serve as buffer layers.
(3) Surfacing welding a cobalt-based alloy; the laser scanning speed is 8mm/s, the laser power is 1500W, the powder feeding speed is 10g/min, the coaxial gas flow is 16L/min, the preheating temperature before welding is more than 200 ℃, the post-heating temperature is controlled to be about 430-480 ℃, the interlayer temperature is controlled to be 300-350 ℃, and one or more layers of cobalt-based alloy are welded on the buffer layer according to the welding ratio.
Table 6 shows the welding process parameters of the laser beam deposition surfacing of the nickel-based alloy and the cobalt-based alloy in examples 1 to 5
In specific implementation, the valve seat with the surfacing layer sealing surface is subjected to heat treatment, and the heat treatment temperature is 340-670 ℃. The surfacing also includes shielded metal arc welding and submerged arc welding. The temperature of the heat treatment after surfacing needs to be determined according to the application and the working environment of the sealing surface of the valve seat, taking a steam turbine as an example, the working steam temperatures of different types of steam turbines are different, and the specified new steam temperatures (DEG C) of the nine types of steam turbines are as follows: 1. low-pressure non-reheat steam turbine: 340 ℃; 2. secondary medium pressure non-reheat steam turbine: 390 deg.C; 3. medium pressure non-reheat steam turbine: 435 ℃, 450 ℃ and 470 ℃; 4. a sub-high pressure non-reheat steam turbine: 435 ℃, 450 ℃, 460 ℃ and 470 ℃; 5. high-pressure non-reheat steam turbine: 535 ℃; 6. ultrahigh pressure reheat steam turbine: 535 deg.C, 537 deg.C, 538 deg.C, 540 deg.C; 7. subcritical reheat type pressure turbine: 535 deg.C, 537 deg.C, 538 deg.C, 540 deg.C; 8. supercritical reheat pressure turbine: 538 ℃ and 566 ℃; 9. ultra supercritical pressure turbine: 566 deg.C, 580 deg.C, 593 deg.C, 600 deg.C. In addition, the new steam temperature of the ultra supercritical pressure turbine can be agreed by the supply and demand parties, and the temperature of the new steam can exceed 600 ℃, so that the heat treatment temperature range is 340-670 ℃.
Third, performance test
Comparative example 1 is an unwelded base material FB2 martensitic steel, and comparative example 2 is an unwelded base material F92 martensitic steel.
In order to intuitively explain various performance parameters of various embodiments, the wear resistance and the high temperature resistance are quantified by high temperature wear percentage, friction coefficient and wear loss; the high-temperature impact test length change percentage, the diameter change percentage and the crack initiation number are used for quantifying the impact resistance, the crack resistance and the high-temperature resistance; the crack resistance and the high temperature resistance are quantified by the number of crack initiation strips in a high-low temperature cycle test; the abrasion resistance, crack resistance and high temperature resistance are quantified by the number of crack initiation strips in the solid particle erosion test; the thermal stability, oxidation resistance and high temperature resistance are quantified by the dilution rate of a high temperature aging test.
Wherein the content of the first and second substances,
TABLE 7
The high-temperature wear test, the high-temperature impact test, the high-temperature and low-temperature cycle test, the solid particle erosion test and the high-temperature aging test are respectively carried out on the samples 1 to 5 and the comparative samples 1 to 2 under the condition of 650 ℃. From the results in table 7, it can be seen that the comparative example has a large wear amount and much lower wear resistance than the examples under high temperature conditions, and similarly, the percentage change in length and the percentage change in diameter of the impact test are much higher than the examples, which indicates that the comparative example is very easy to deform under high temperature conditions, and the examples have good impact resistance, and the comparative example has several cracks after the high temperature solid particle erosion test, and the examples all have cracks, which indicates that the examples have good scratch resistance, erosion resistance and high temperature resistance, and the dilution ratio of the main elements in the high temperature aging test is kept in a low range, which indicates that the examples have good thermal stability, oxidation resistance and high temperature resistance, and can operate normally under high temperature conditions. The post-welding observation of the embodiments 1 to 5 is carried out, and the visual inspection and the penetration inspection of the welded test piece of the embodiment 2 are carried out by taking the embodiment 2 as an example, so that the macrocracks are avoided. Referring to fig. 1-2, under an optical microscope and a scanning electron microscope, the optical microscope images of the nickel-based alloy material (lower part) and the cobalt-based alloy material (upper part) of the valve seat sealing surface overlaying welding of the embodiment 2 have no defects of micro-cracks, pores, looseness, fusion failure and the like. Example 2 optical microscopic images of base material (lower part) and nickel-based alloy material (upper part) of the valve seat sealing surface. The observation shows that the alloy has no defects of micro-cracks, pores, looseness, non-fusion and the like.
According to the invention, after research on the base material of the sealing surface of the valve seat, the unexpected discovery that when the nickel-based alloy is used as a buffer layer, the nickel-based alloy is firstly overlaid on the base body of the sealing surface of the valve seat, and then the cobalt-based alloy is overlaid, the advantages/characteristics of the two materials can be well combined, so that the overlaying layer of the sealing surface can simultaneously meet the comprehensive performances of wear resistance, impact resistance, corrosion resistance, high temperature resistance, scratch resistance, oxidation resistance, crack resistance and the like, and the sealing surface of the valve seat is fixed in gold soup. The invention adopts argon tungsten arc welding (GTAW or TIG), Shielded Metal Arc Welding (SMAW), plasma arc hot spray welding (PAW), laser beam deposition overlaying (LBW) and Submerged Arc Welding (SAW) for overlaying, all can achieve the technical effect of the invention, but after researching a plurality of welding methods, the sealing surface of the valve seat after overlaying by the PAW process has more excellent wear resistance, and the sealing surface of the valve seat after overlaying by the TIG and LBW processes also has better performance than the sealing surface of the existing valve seat.
Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention and not for limiting the technical solutions, and those skilled in the art should understand that modifications or equivalent substitutions can be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions, and all that should be covered by the claims of the present invention.
Claims (10)
1. The alloy material for the surfacing layer of the sealing surface of the valve seat is characterized by comprising a nickel-based alloy and a cobalt-based alloy, wherein the mass ratio of the nickel-based alloy to the cobalt-based alloy is 1: 1-5;
the nickel-based alloy comprises the following components in percentage by mass: 20-23% of chromium; 8-10% of molybdenum; 3.15 to 4.15 percent of niobium; iron < 5%; aluminum < 0.4%; titanium < 0.4%; carbon < 0.1%; manganese < 0.5%; silicon < 0.5%; cobalt is less than 1%; phosphorus < 0.015%; sulfur < 0.015%; the balance being nickel;
the cobalt-based alloy comprises the following components in percentage by mass: 28-32% of chromium; molybdenum < 1.5%; iron < 3%; carbon is 0.9-1.4%; manganese is less than 2%; silicon < 1.5%; nickel is less than 3%; phosphorus < 0.015%; sulfur < 0.015%; 3.5-5.5% of tungsten; the balance being cobalt.
2. The alloy material for a weld overlay of a valve seat sealing surface according to claim 1, wherein the nickel alloy is used as a buffer layer under the cobalt-based alloy and is provided on a substrate surface of the valve seat sealing surface.
3. A welding process for a surfacing layer of a sealing surface of a valve seat, which is characterized in that the alloy material according to any one of claims 1-2 is used as the surfacing layer, and the welding is carried out by the following method:
firstly, polishing and cleaning a base body of the sealing surface of the valve seat, then overlaying a nickel-based alloy on the base body as a buffer layer, and overlaying a cobalt-based alloy to obtain the sealing surface of the valve seat with an overlaying layer.
4. The welding process for the overlaying layer on the sealing surface of the valve seat according to claim 3, wherein the overlaying layer is argon tungsten-arc welding and is carried out by the following steps:
(1) firstly, polishing and cleaning a base material of a sealing surface of a valve seat;
(2) forming a V-shaped groove on a base material of the ring piece on the sealing surface of the valve seat, overlaying the nickel-based alloy, connecting the polarity of a power supply in a direct current reverse mode, wherein the welding current is 200-300A, the welding voltage is 9-15V, the welding speed is 70-95 mm/min, the interlayer temperature is 100 ℃, and overlaying of the nickel-based alloy is completed according to the proportion, the number and the pass of overlaying;
(3) and (2) surfacing the cobalt-based alloy, wherein the polarity of a power supply is in direct current positive connection, the welding current is 200-300A, the welding voltage is 9-15V, the welding speed is 70-95 mm/min, the preheating temperature before welding is greater than 200 ℃, the post-heating temperature is controlled to be 430-480 ℃, the interlayer temperature is controlled to be 300-350 ℃, and surfacing of the cobalt-based alloy is completed according to surfacing proportion, layers and passes.
5. The welding process for a weld overlay for a sealing surface of a valve seat according to claim 3, wherein the weld overlay is a plasma arc thermal weld overlay performed by the steps of:
(1) firstly, polishing and cleaning a base material of a sealing surface of a valve seat;
(2) surfacing of a nickel-based alloy: the polarity of the power supply adopts direct current reverse connection, and one or more layers of nickel-based alloys are subjected to surfacing on the surface of the sealing surface matrix according to surfacing proportion to serve as buffer layers;
(3) surfacing welding a cobalt-based alloy; and the polarity of the power supply adopts direct current positive connection, and one or more layers of cobalt-based alloy are subjected to surfacing on the buffer layer according to the surfacing proportion.
6. The welding process for the overlaying layer on the sealing surface of the valve seat as claimed in claim 5, wherein in the step (2), when the first layer of the nickel-based alloy is overlaid, the welding current is 162-200A, the welding voltage is 27-33V, the welding speed is 80-110 mm/min, the powder feeding speed is 20-33 g/min, the ion arc gas is argon, the flow rate is 180-200L/min, the shielding gas is argon, the flow rate is 540-600L/min, the powder feeding gas is argon, and the flow rate is 380-420L/min; when the nickel-based alloy is subjected to surfacing welding on a second layer and above, the welding current is 162-198A, the welding voltage is 27-33V, the welding speed is 80-110 mm/min, the powder feeding speed is 20-33 g/min, the ion arc gas is argon, the flow rate is 180-200L/min, the shielding gas is argon, the flow rate is 540-600L/min, the powder feeding gas is argon, the flow rate is 380-420L/min, the preheating temperature before welding is 90-110 ℃, and the interlayer temperature is controlled at 140-160 ℃.
7. The welding process for the overlaying layer on the sealing surface of the valve seat according to claim 5, wherein in the step (3), when the cobalt-based alloy overlaying layer is overlaid on the first layer, the welding current is 162-200A, the welding voltage is 27-33V, the welding speed is 70-101 mm/min, the powder feeding speed is 33-40 g/min, the ion arc gas is argon, the flow rate is 170-190L/min, the shielding gas is argon, the flow rate is 540-660L/min, the powder feeding gas is argon, and the flow rate is 380-420L/min; when the second layer and above of the cobalt-based alloy are subjected to surfacing welding, the welding current is 162-198A, the welding voltage is 27-33V, the welding speed is 70-101 mm/min, the powder feeding speed is 33-40 g/min, the ion arc gas is argon, the flow rate is 170-190L/min, the shielding gas is argon, the flow rate is 540-660L/min, the powder feeding gas is argon, and the flow rate is 380-420L/min; the preheating temperature before welding is more than 200 ℃, the post-heating temperature is controlled to be 430-480 ℃, and the interlayer temperature is controlled to be 300-350 ℃.
8. The welding process for the weld overlay of the sealing surface of the valve seat according to claim 3, wherein the weld overlay is a laser beam deposition weld overlay, and the welding process comprises the following steps:
(1) firstly, polishing and cleaning a base material of a sealing surface of a valve seat;
(2) surfacing of a nickel-based alloy: the laser scanning speed is 8mm/s, the laser power is 1300W, the powder feeding speed is 10g/min, the coaxial gas flow is 16L/min, the interlayer temperature is controlled to be 90-110 ℃, and one or more layers of nickel-based alloys are subjected to surfacing welding on the surface of the sealing surface substrate according to the surfacing welding proportion to serve as buffer layers;
(3) surfacing welding a cobalt-based alloy; the laser scanning speed is 8mm/s, the laser power is 1500W, the powder feeding speed is 10g/min, the coaxial gas flow is 16L/min, the preheating temperature before welding is more than 200 ℃, the post-heating temperature is controlled to be about 430-480 ℃, the interlayer temperature is controlled to be 300-350 ℃, and one or more layers of cobalt-based alloy are welded on the buffer layer according to the welding ratio.
9. The process for welding the resurfacing layer of the sealing surface of the valve seat according to claim 3, wherein the valve seat having the sealing surface of the resurfacing layer is subjected to heat treatment at a temperature of 340 to 670 ℃.
10. The welding process of the overlay welding for the valve seat sealing surface according to claim 3, wherein the overlay welding is shielded metal arc welding or submerged arc welding.
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114799747A (en) * | 2022-04-14 | 2022-07-29 | 无锡智能自控工程股份有限公司 | Composite manufacturing process for strengthening high-temperature wear resistance of valve shaft for valve |
Citations (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS62275511A (en) * | 1986-02-17 | 1987-11-30 | Kawasaki Steel Corp | Hot rolling roll having excellent wear resistance and its manufacture |
| JPH08118049A (en) * | 1994-08-31 | 1996-05-14 | Ishikawajima Harima Heavy Ind Co Ltd | Laser cladding method |
| JPH08215842A (en) * | 1995-02-15 | 1996-08-27 | Mitsubishi Heavy Ind Ltd | High temp. sliding member |
| JPH1085933A (en) * | 1996-09-10 | 1998-04-07 | Nippon Steel Corp | Multi-layered building-up method for hot extruding or forging die |
| WO2011058793A1 (en) * | 2009-11-12 | 2011-05-19 | 日鍛バルブ株式会社 | Seat faced poppet valve and method for producing same |
| CN103286459A (en) * | 2013-06-05 | 2013-09-11 | 宁波旭元机械制造有限公司 | Large-scale PTA drying machine sealing surface abrasion on-site precise pulse surfacing welding repair process |
| WO2014121060A1 (en) * | 2013-01-31 | 2014-08-07 | Siemens Energy, Inc. | Localized repair of superalloy component |
| CN104864174A (en) * | 2015-05-22 | 2015-08-26 | 上海平安高压调节阀门有限公司 | Build up welding structure of ultra-supercritical generator set steam valve sealing face |
| CN105290564A (en) * | 2015-11-10 | 2016-02-03 | 中广核工程有限公司 | Sealing face surfacing method of nuclear power station pressure releasing valve |
| CN108526654A (en) * | 2018-06-25 | 2018-09-14 | 河北工业大学 | A kind of large-diameter valves sealing ring overlaying method |
| CN109693026A (en) * | 2018-12-27 | 2019-04-30 | 浙江富春江水电设备有限公司 | A kind of combination overlaying method for outer circle large area stellite hardfacing |
| CN110125515A (en) * | 2019-04-24 | 2019-08-16 | 武汉船用机械有限责任公司 | Nickel alloy overlaying method |
| CN110344050A (en) * | 2019-07-22 | 2019-10-18 | 重庆跃进机械厂有限公司 | A kind of laser cladding method of diesel engine spiracle sealing surface |
-
2021
- 2021-12-24 CN CN202111599490.8A patent/CN114131242B/en active Active
Patent Citations (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS62275511A (en) * | 1986-02-17 | 1987-11-30 | Kawasaki Steel Corp | Hot rolling roll having excellent wear resistance and its manufacture |
| JPH08118049A (en) * | 1994-08-31 | 1996-05-14 | Ishikawajima Harima Heavy Ind Co Ltd | Laser cladding method |
| JPH08215842A (en) * | 1995-02-15 | 1996-08-27 | Mitsubishi Heavy Ind Ltd | High temp. sliding member |
| JPH1085933A (en) * | 1996-09-10 | 1998-04-07 | Nippon Steel Corp | Multi-layered building-up method for hot extruding or forging die |
| WO2011058793A1 (en) * | 2009-11-12 | 2011-05-19 | 日鍛バルブ株式会社 | Seat faced poppet valve and method for producing same |
| WO2014121060A1 (en) * | 2013-01-31 | 2014-08-07 | Siemens Energy, Inc. | Localized repair of superalloy component |
| CN103286459A (en) * | 2013-06-05 | 2013-09-11 | 宁波旭元机械制造有限公司 | Large-scale PTA drying machine sealing surface abrasion on-site precise pulse surfacing welding repair process |
| CN104864174A (en) * | 2015-05-22 | 2015-08-26 | 上海平安高压调节阀门有限公司 | Build up welding structure of ultra-supercritical generator set steam valve sealing face |
| CN105290564A (en) * | 2015-11-10 | 2016-02-03 | 中广核工程有限公司 | Sealing face surfacing method of nuclear power station pressure releasing valve |
| CN108526654A (en) * | 2018-06-25 | 2018-09-14 | 河北工业大学 | A kind of large-diameter valves sealing ring overlaying method |
| CN109693026A (en) * | 2018-12-27 | 2019-04-30 | 浙江富春江水电设备有限公司 | A kind of combination overlaying method for outer circle large area stellite hardfacing |
| CN110125515A (en) * | 2019-04-24 | 2019-08-16 | 武汉船用机械有限责任公司 | Nickel alloy overlaying method |
| CN110344050A (en) * | 2019-07-22 | 2019-10-18 | 重庆跃进机械厂有限公司 | A kind of laser cladding method of diesel engine spiracle sealing surface |
Non-Patent Citations (1)
| Title |
|---|
| 周路云;刘书宏;符明海;: "金属阀门密封面镍基合金晶间腐蚀敏感度的研究", 化工装备技术, no. 01 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114799747A (en) * | 2022-04-14 | 2022-07-29 | 无锡智能自控工程股份有限公司 | Composite manufacturing process for strengthening high-temperature wear resistance of valve shaft for valve |
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