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CN-121972667-A - Copper graphite alloy-steel bimetal self-lubricating slide plate material and application thereof

CN121972667ACN 121972667 ACN121972667 ACN 121972667ACN-121972667-A

Abstract

The invention belongs to the technical field of composite material manufacturing, and particularly relates to a copper graphite alloy-steel base bimetal self-lubricating slide plate material applied to a turbine slide pin system and a preparation method thereof. The copper-graphite alloy lubricating layer powder is paved on the surface of the steel-based composite board and realizes gradient combination through layered powder paving, and the copper-graphite alloy lubricating layer powder comprises 88-96% of copper-tin alloy powder, 2-6% of natural graphite powder and 2-6% of artificial flake graphite powder, the paved composite board is sequentially pressed, primarily sintered and hot isostatic pressed, and finally the copper-graphite alloy-steel bimetal self-lubricating sliding board material is obtained through machining surface treatment. The copper graphite alloy-steel bimetal self-lubricating slide plate material prepared by the method has excellent bearing capacity, excellent self-lubricating performance and friction resistance, long service life and capability of meeting the use requirement of a turbine slide pin system under severe working conditions.

Inventors

  • LV XINQUN
  • LUO TAO

Assignees

  • 长沙迈特锐新材料有限公司

Dates

Publication Date
20260505
Application Date
20260210

Claims (10)

  1. 1. The copper graphite alloy-steel bimetal self-lubricating slide plate material is characterized by comprising the following steps of: plating copper or nickel on the surface of the steel substrate to obtain a steel-based composite board, wherein the steel-based composite board is a nickel-plated steel-based composite board or a copper-plated steel-based composite board; copper-graphite alloy lubricating layer powder is paved on the surface of the steel-based composite board, gradient combination is realized through layered powder paving, and the copper-graphite alloy lubricating layer powder consists of the following components: 88-96% of copper-tin alloy powder; 2-6% of natural graphite powder; 2-6% of artificial flake graphite powder; And (3) sequentially carrying out pressing, preliminary sintering treatment and hot isostatic pressing treatment on the composite board after powder spreading, and finally carrying out machining surface treatment to obtain the copper graphite alloy-steel bimetal self-lubricating slide board material.
  2. 2. The copper graphite alloy-steel bimetal self-lubricating slide plate material is characterized in that the steel plate is a conventional steel substrate, the steel plate comprises A3 steel and No. 45 steel, the thickness of a plating layer on the surface of the steel substrate is preferably 5-20 microns, preferably 8-15 microns, and the plating layer is a copper layer.
  3. 3. The copper graphite alloy-steel bimetal self-lubricating slide plate material disclosed in claim 1 is characterized in that the copper graphite alloy lubricating layer comprises copper tin alloy powder, natural graphite powder and artificial graphite powder, and the powder spreading thickness of the copper graphite alloy lubricating layer is 1-8 mm, preferably 2-6 mm, more preferably 3-6 mm, still more preferably 4-6 mm.
  4. 4. A copper graphite alloy-steel bi-metal self-lubricating slide plate material as set forth in claim 3 wherein the copper graphite alloy lubricating layer comprises a one-layer or 2-layer structure, and when it is a 2-layer structure, the one layer adjacent to the steel substrate is defined as a first copper graphite alloy lubricating layer, and the copper graphite alloy lubricating layer in contact with the first copper graphite alloy lubricating layer and remote from the steel substrate is defined as a first copper graphite alloy lubricating layer, wherein the copper content in the first copper graphite alloy lubricating layer is greater than the copper content in the second copper graphite alloy lubricating layer.
  5. 5. A copper graphite alloy-steel bi-metal self-lubricating skateboard material according to claim 3, wherein: the tin content of the copper-tin alloy powder is 9-11%, the grain size range is less than or equal to 200 meshes, and the powder is in irregular grains; The purity of the natural graphite powder is more than 99.5%, the grain diameter range is-50+100 meshes, and the shape is flake granular; the purity of the artificial graphite powder is more than 99%, the grain diameter range is less than or equal to 300 meshes, and the shape is nearly spherical.
  6. 6. The copper graphite alloy-steel bi-metal self-lubricating slide plate material according to claim 1, wherein: the preferable mass ratio of the copper-tin alloy powder to the natural graphite powder to the crystalline flake graphite powder is 90-95:2.5-5:2.5-5. As a further preferable mode, the mass ratio of the copper-tin alloy powder to the natural graphite powder to the crystalline flake graphite powder is 92-95:2.5-4:2.5-4. The method comprises the scheme that the mass ratio of copper-tin alloy powder to natural graphite powder to crystalline flake graphite powder is 94:3:3 and the scheme that the mass ratio of copper-tin alloy powder to natural graphite powder to crystalline flake graphite powder is 95:2.5:2.5, and the scheme that the mass ratio of copper-tin alloy powder to natural graphite powder to crystalline flake graphite powder is 92:4:4.
  7. 7. The copper graphite alloy-steel bi-metal self-lubricating slide plate material according to claim 1, wherein: the pressing pressure of the powder layers of the transition layer and the copper graphite alloy lubricating layer is 3-7 MPa, preferably 4-6 MPa, and the pressing pressure maintaining time is 5-20 s, preferably 10-15 s.
  8. 8. The copper graphite alloy-steel bi-metal self-lubricating slide plate material according to claim 4, wherein: The raw material powder used for the first copper-graphite alloy lubricating layer consists of 95 percent by mass of copper-tin alloy powder, 2.5 percent by mass of natural graphite powder and 2.5 percent by mass of flake graphite powder; The raw material powder used for the second copper-graphite alloy lubricating layer consists of 92% by mass, 4% by mass and 4% by mass of copper-tin alloy powder, natural graphite powder and flake graphite powder; Preferably, the thickness of the first copper graphite alloy lubricating layer is 2.5-3 mm, and the thickness of the second copper graphite alloy lubricating layer is 2.5-3 mm.
  9. 9. The copper graphite alloy-steel bi-metal self-lubricating slide plate material according to claim 1, wherein: The sintering temperature of the primary sintering treatment after the pressing process is 740-800 ℃, preferably 750-800 ℃, further preferably 750-780 ℃, and the heat preservation time is 60-120 minutes, preferably 85-95 minutes, wherein the atmosphere of the primary sintering treatment is ammonia decomposition atmosphere; The process temperature of the hot isostatic pressing treatment is 780-840 ℃, preferably 800-820 ℃, more preferably 800-815 ℃, the pressure is 100-130 MPa, preferably 110-120 MPa, more preferably 110-115 ℃, and the heat preservation time is 30-90 minutes, preferably 55-65 minutes.
  10. 10. The use of a copper graphite alloy-steel bi-metal self-lubricating slide plate material according to any one of claims 1-9, wherein the copper graphite alloy-steel bi-metal self-lubricating slide plate is applied to a turbine sliding pin system.

Description

Copper graphite alloy-steel bimetal self-lubricating slide plate material and application thereof Technical Field The invention belongs to the technical field of composite material manufacturing, and particularly relates to a copper graphite alloy-steel bimetal self-lubricating slide plate material and application thereof. Background Steam turbines, which are one of the key core devices in power plants, experience significant changes in their component temperatures during start-up, operation, or shutdown. The cylinder interior transitions from a cold state to a normal operating hot state (and vice versa during shutdown), the stator components undergo expansion or contraction, as does the rotor. The structure of ensuring the relatively stable expansion between the stator and the rotor of the steam turbine forms a sliding pin system of the steam turbine, and the normal operation of the sliding pin system directly relates to the integral safety of the unit. The sliding pin system operates in high temperature and high load environment for a long time, and needs to have stable lubrication and friction resistance and low maintenance requirements, so that extremely high requirements are placed on the design and material selection of the sliding pin system. In the turbine sliding pin system, the most easily-caused clamping part is a moving pair between a turbine bearing box and a base platen. In early stages, the sliding pair commonly adopts a carbon structural steel sliding block, and high-temperature-resistant lubricating grease is injected to reduce friction resistance. Meanwhile, high-temperature lubricating grease used for a long time can be gradually oxidized, so that the friction resistance is increased, the service life is shortened, the smooth expansion of a turbine sliding pin system is further influenced, and the normal operation of a unit is influenced. Subsequently, iron-based embedded graphite type self-lubricating sliders were developed to replace steel sliders. The sliding block is formed by directly pressing a formed graphite lubrication column into a hole which is made in advance on an iron substrate or filling the formed graphite lubrication column into the hole by matching with an adhesive. During friction, the steel matrix takes up the load. The embedded graphite lubricant forms a layer of solid lubricating film on the friction surface, so that the metal friction surfaces of the moving pair are not in direct contact, and the lubricating effect is realized. Compared with an oil lubricated steel slider, the technology has obvious improvement in lubrication effect and service life, but still has the problems of rust on the surface of the steel slider and insufficient lubrication performance after long-time use. Therefore, there is a need to develop a novel metal-based self-lubricating material to meet the requirements of turbine sliding pin systems for severe service conditions such as long life, high temperature and high load. The utility model patent CN 202325708 (name: a turbine sliding pin system) proposes a metal lubrication sheet, which is applied to solve the problem of jamming in the turbine sliding pin system. The metal lubricating sheet is provided with three layers of self-lubricating coatings, and the friction coefficient of the metal lubricating sheet reaches 0.16. However, no more detailed information is disclosed about the specific materials and structural details of the metallic lubricant sheet. The invention patent with publication number CN 117431592 (name: a copper/steel bimetal self-lubricating slide plate, a preparation method and application thereof) discloses a copper/steel bimetal self-lubricating slide plate, which is composed of a steel substrate, a nickel plating layer, a copper alloy bearing layer, a copper alloy lubricating layer and an initial lubricating coating which are sequentially laminated, and is suitable for a steam turbine supporting mechanism. The preparation process of the sliding plate involves twice plating treatment, powder laying, pressing, sintering treatment, rolling treatment and aging treatment, and has long process flow and complex treatment steps. In the copper alloy lubrication layer, copper-nickel-tin-lead powder containing lead is used, which has environmental risks due to toxicity of lead. In addition, the solid lubricant powder combination of the copper alloy lubricating layer comprises graphite powder, baF 2 powder, caF 2 powder, ceO 2 powder and WS 2 powder, and the proportioning scheme of the solid lubricant powder is complex. In the copper alloy lubrication layer, the total content of the solid lubricant is preferably not less than 14%, and too high a content of the solid lubricant may impair the carrying capacity of the copper alloy layer, thereby bringing a potential safety risk. Unfortunately, no compressive strength related data for copper alloy lubrication layers is provided in this invention. Disclosure of Invention The invention ai