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CN-121972861-A - Flux-cored wire for low-pressure cylinder guide plate and preparation method thereof

CN121972861ACN 121972861 ACN121972861 ACN 121972861ACN-121972861-A

Abstract

The invention relates to the technical field of welding wire manufacture, in particular to a flux-cored wire for a low-pressure cylinder guide plate and a preparation method thereof, comprising the steps of sequentially polishing, cleaning and drying the low-pressure cylinder guide plate to obtain a pretreatment plate; and (3) designing a cladding process of multi-layer multi-pass welding based on MIG welding by using a flux-cored wire, and preparing a cladding layer on the surface of the pretreatment plate. According to the invention, the coated WC powder is added into the composite powder core, the Al and Nano-TiC are added into the welding wire outer skin, so that WC particles and Nano-TiC particles are uniformly dispersed in the cladding layer in the welding process, the structure grains are thinned, the hardness, the wear resistance and the corrosion resistance of the cladding layer are greatly improved, and compared with the Nano-TiC particles arranged in the composite powder core, the Nano-TiC powder can further enhance the overall performance of the cladding layer by arranging the Nano-TiC particles in the welding wire outer skin.

Inventors

  • ZHANG XIANGJUN
  • Zu Pingwen
  • XU SHUAI
  • YANG WENTAO
  • NIE HAIJUN
  • WANG LONG
  • WANG YUJIAN
  • CHEN WENQI

Assignees

  • 华电电力科学研究院有限公司

Dates

Publication Date
20260505
Application Date
20260128

Claims (10)

  1. 1. The flux-cored wire for the low-pressure cylinder guide plate is characterized by comprising a composite powder core and a wire outer skin; the composite powder core comprises, by mass, 5-15% of Ni powder, 0.5-1% of Si powder, 10-15% of Cr powder, 1-2% of Nb powder, 8-10% of coated WC powder and the balance of Cu powder; the welding wire sheath comprises, by mass, 8-10% of Nano-TiC powder, 30-40% of Al powder and the balance of Cu powder.
  2. 2. The flux-cored wire for low-pressure cylinder deflectors of claim 1, wherein the filler wire has a filling rate of 30-40% and a diameter of 1.2mm.
  3. 3. The flux-cored wire for low-pressure cylinder guide plates according to claim 1, wherein the coated WC powder is a copper film vapor deposited on the surface of the WC powder, the copper film thickness is 1-1.5 μm, and the WC powder has a particle diameter of 80-100 μm.
  4. 4. The flux-cored wire for low-pressure cylinder deflectors of claim 1, wherein the thickness of the wire sheath is 0.3-0.5mm and the particle size of nano-TiC powder is 100-150nm.
  5. 5. The flux-cored wire for low-pressure cylinder deflectors of claim 1, wherein the wire sheath is prepared by the steps of: S1, placing Al powder and Cu powder into a melting furnace, and melting at 1100-1150 ℃ to obtain a melt; S2, preheating Nano-TiC powder to 150-200 ℃; S3, blowing the preheated Nano-TiC powder into a melting furnace, and uniformly stirring to obtain a mixed melt; S4, injecting the mixed melt into a die, cooling and forming to obtain a casting, and annealing and rolling to obtain the welding wire sheath.
  6. 6. The flux-cored wire for low-pressure cylinder deflectors according to claim 5, wherein argon is introduced into the furnace to prevent oxidation in steps S1 and S3.
  7. 7. The flux-cored wire for low-pressure cylinder deflectors according to claim 5, wherein in step S4, the annealing treatment is performed by heating the cast to 450-550 ℃ and maintaining the temperature for 8-10 hours, followed by air cooling to room temperature.
  8. 8. The method for manufacturing a flux-cored wire for a deflector of a low pressure cylinder according to any one of claims 1 to 7, wherein raw materials required for the composite powder core are weighed and mixed uniformly in proportion, and the raw materials are matched with a wire sheath to prepare the flux-cored wire by a wire drawing machine.
  9. 9. A method for preparing a cladding layer of a deflector of a low pressure cylinder, which adopts the flux-cored wire as claimed in any one of claims 1 to 7, and is characterized by comprising the following steps: (1) Polishing, cleaning and drying the low-pressure cylinder guide plate in sequence to obtain a pretreatment plate; (2) And (3) using a flux-cored wire, designing a cladding process of multi-layer multi-pass welding based on MIG welding, and preparing a cladding layer on the surface of the pretreatment plate.
  10. 10. The method for preparing a cladding layer of a deflector for a low pressure cylinder according to claim 9, wherein in the step (2), parameters of MIG welding are that welding current is 200-210A, welding voltage is 22-23V, welding speed is 0.6m/min, pure Ar is used as protective gas, and flow rate is 12L/min; The cladding layers are three layers, the thickness of each layer is 1-1.5mm, each layer comprises a plurality of parallel overlapped welding beads, the width of each welding bead is 5mm, and the cladding overlap coverage rate of adjacent welding beads is 45-50%.

Description

Flux-cored wire for low-pressure cylinder guide plate and preparation method thereof Technical Field The invention relates to the technical field of welding wire manufacturing, in particular to a flux-cored wire for a low-pressure cylinder guide plate and a preparation method thereof. Background Along with the rapid development of economy, the requirements of large-scale, long service life and high-efficiency operation of energy equipment are continuously improved, and higher requirements are put on the comprehensive performance of key component materials. Because a single material is limited by working conditions such as strong corrosion, high-humidity steam flow, high-speed scouring and the like, multiple requirements on wear resistance, corrosion resistance and high-temperature performance in practical engineering application are often difficult to meet, and development of a composite functional material system integrating excellent properties of multiple materials is needed. The low-pressure cylinder guide plate is an important part in the steam turbine, is widely applied to large-scale power generation equipment such as thermal power, nuclear power and the like, and mainly has the effects of guiding reasonable flow of high-volume flow rate steam in a low-pressure section and improving flow field stability and energy conversion efficiency. The deflector is exposed to the high-humidity saturated steam environment for a long time in the operation process, is subjected to the influence of various complex working conditions such as high-speed airflow scouring, water drop erosion, temperature alternation, micro-vibration and the like, is extremely easy to generate surface abrasion, corrosion or fatigue damage, leads to flow field distortion and overall efficiency reduction, even causes structural damage, and threatens the safe operation of equipment. Structural steels such as Q345 steel have found application in certain baffles or their base structures due to their excellent strength, toughness and weldability, but have limited corrosion resistance and anti-scour properties. As a cladding method with high efficiency and high deposition rate, the metal inert gas shielded welding (MIG welding) has the advantages of controllable heat input, continuous feeding of welding wires, high automation degree and the like, and is very suitable for preparing alloy layers on the surfaces of structural members. The performance of the steel can be improved by coating a cladding layer on the surface of steel such as Q345 steel by MIG welding. Based on the structure, a flux-cored wire for a low-pressure cylinder guide plate and a preparation method thereof are provided. Disclosure of Invention Aiming at the defects of the prior art, the invention provides a flux-cored wire for a low-pressure cylinder guide plate and a preparation method thereof, wherein coated WC powder is added into a composite powder core, al and Nano-TiC are added into a wire sheath, WC particles and Nano-TiC particles are uniformly dispersed in a cladding layer in a welding process, so that structure grains are thinned, and the hardness, wear resistance and corrosion resistance of the cladding layer are greatly improved. In order to achieve the aim, the invention provides the technical scheme that the flux-cored wire for the low-pressure cylinder guide plate comprises a composite powder core and a wire outer skin; the composite powder core comprises, by mass, 5-15% of Ni powder, 0.5-1% of Si powder, 10-15% of Cr powder, 1-2% of Nb powder, 8-10% of coated WC powder and the balance of Cu powder; The welding wire sheath comprises, by mass, 8-10% of Nano-TiC powder (Nano titanium carbide), 30-40% of Al powder and the balance of Cu powder. Preferably, the filling rate of the flux-cored wire is 30-40%, and the diameter of the flux-cored wire is 1.2mm. Preferably, the coated WC powder is prepared by steaming copper film on the surface of WC powder (tungsten carbide powder), wherein the thickness of the copper film is 1-1.5 mu m, and the particle size of the WC powder is 80-100 mu m. Preferably, the thickness of the welding wire sheath is 0.3-0.5mm, and the particle size of nano-TiC powder is 100-150nm. The preparation method of the welding wire sheath comprises the steps of S1, putting Al powder and Cu powder into a melting furnace, melting at 1100-1150 ℃ to obtain a melt, S2, preheating Nano-TiC powder to 150-200 ℃, S3, blowing the preheated Nano-TiC powder into the melting furnace, uniformly stirring to obtain a mixed melt, S4, injecting the mixed melt into a mold, cooling and forming to obtain a casting, and annealing and rolling to obtain the welding wire sheath. Preferably, in steps S1 and S3, argon is introduced into the furnace to prevent oxidation. Preferably, in the step S4, the annealing treatment is to heat the casting to 450-550 ℃ and keep the temperature for 8-10 hours, and then air-cool to room temperature. The invention provides a preparation metho