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CN-121988821-A - High-entropy alloy-heat-resistant steel dissimilar alloy with high entropy brazing interface and welding method thereof

CN121988821ACN 121988821 ACN121988821 ACN 121988821ACN-121988821-A

Abstract

The invention relates to the technical field of dissimilar metal material welding, in particular to a high-entropy alloy-heat-resistant steel dissimilar alloy with a high entropy brazing interface and a welding method thereof. The high-entropy alloy is smelted and prepared, is machined into a plate through a large deformation cold rolling process, and is subjected to dissimilar metal brazing treatment with the high-strength martensitic heat-resistant steel plate, so that a single-phase solid solution with a simple structure is generated at a welding interface instead of a traditional brittle hard IMC phase by virtue of high mixed entropy of the high-entropy alloy, the excellent plasticity of the high-entropy alloy effectively inhibits the initiation and expansion of microcracks at the welding interface, the mechanical property of a welding spot is greatly improved, and an effective thought is provided for welding dissimilar metals.

Inventors

  • JI XINBO

Assignees

  • 国网山东省电力公司电力科学研究院

Dates

Publication Date
20260508
Application Date
20260316

Claims (10)

  1. 1. The high-entropy alloy-heat-resistant steel dissimilar alloy welding method with high entropy of a brazing interface is characterized by comprising the following steps of: (1) Grinding, cleaning and drying the high-entropy alloy plate and the heat-resistant steel plate, and fixing the high-entropy alloy plate and the heat-resistant steel plate into a shear sample; the heat-resistant steel plate is used as a base plate, and the high-entropy alloy plate is used as brazing filler metal, wherein the high-entropy alloy is FeCoCrNiMn alloy or CoCrNi alloy; (2) Heating the heat-resistant steel substrate and the high-entropy alloy solder to a temperature slightly higher than the melting point of the solder by adopting induction current, keeping the solder melted and the substrate solid, and filling the gap by capillary action; (3) Welding under a protective atmosphere, mutually diffusing and dissolving the liquid high-entropy alloy brazing filler metal and the heat-resistant steel metal substrate to form a brazing joint, and solidifying the brazing filler metal after cooling to finish brazing welding; (4) And ultrasonically cleaning the welding part by using ethanol to remove brazing filler metal residues and other impurities.
  2. 2. The method of claim 1, wherein in the step (1), ethanol is used for ultrasonic cleaning for 15-40 min; or in the step (1), polytetrafluoroethylene adhesive tape is adopted for fixation, so that movement or deformation in the welding process is prevented.
  3. 3. The method of claim 1, wherein in step (2), a high frequency induction current heater is used to heat by induction current; Or welding the welding spots after the polytetrafluoroethylene tape is fixed in the step (3) at 1300-1350 ℃, brazing in a vacuum brazing furnace, welding 5-10 min under the protection of argon, preserving heat 20-30 min, and cooling; Or, in the step (4), ultrasonic cleaning is carried out for 15-20min.
  4. 4. The method of claim 1, wherein the high-entropy alloy is prepared by: S1, smelting high-entropy alloy, namely, carrying out alloy batching on metal, and smelting the alloy batching into a strip-shaped high-entropy alloy ingot by adopting a magnetic control tungsten electrode non-consumable vacuum arc furnace; s2, carrying out homogenization heat treatment on the smelted strip-shaped high-entropy alloy ingot; And S3, polishing the strip-shaped high-entropy alloy subjected to the high-temperature homogenization heat treatment, and carrying out large-deformation continuous cold rolling treatment to prepare the high-entropy alloy plate with the thickness of 1-2 mm.
  5. 5. The method according to claim 4, wherein the smelting process of the high-entropy alloy in S1 is that firstly, the alloy is smelted into two button ingots with the weight of 80-100 g, then the two button ingots are placed in a water-cooled copper crucible, the strip-shaped high-entropy alloy ingots are smelted, the smelting process is carried out under a protective atmosphere, and the smelting process is repeated for 3-5 times.
  6. 6. The method of claim 4, wherein in S1, the purity of the metal is greater than 99.5 wt%; or, in S1, the size of the long high-entropy alloy ingot is (80-100) mm (25-35) mm (15-20) mm.
  7. 7. The method of claim 1, wherein in S2, the homogenization heat treatment temperature is 900-1200 ℃ for 5-10 hours; or in S3, continuously performing 4-6 times of room temperature cold rolling treatment on the strip-shaped high-entropy alloy.
  8. 8. The method according to claim 1, wherein the high-strength martensitic heat-resistant steel sheet is prepared by cutting a martensitic heat-resistant steel into a long strip, heat-treating at a high temperature for a certain period of time, cooling, and performing continuous large deformation warm rolling treatment.
  9. 9. The method according to claim 6, wherein the heat treatment temperature is 1000-1200 ℃, the heat treatment time is 2-5 hours, or the cooling is performed to 700-750 ℃, 3-5 times of large deformation warm rolling treatment is performed, or the finishing temperature is 600-650 ℃, and the total deformation is 80-85%.
  10. 10. A high entropy alloy-heat resistant steel dissimilar alloy welded by the method of any one of claims 1 to 9, having a braze interface with high entropy.

Description

High-entropy alloy-heat-resistant steel dissimilar alloy with high entropy brazing interface and welding method thereof Technical Field The invention relates to the technical field of dissimilar metal material welding, in particular to a high-entropy alloy-heat-resistant steel dissimilar alloy with a high entropy brazing interface and a welding method thereof. Background The information disclosed in the background of the invention is only for enhancement of understanding of the general background of the invention and is not necessarily to be taken as an admission or any form of suggestion that this information forms the prior art already known to a person of ordinary skill in the art. Dissimilar metal welding has important application in information technology industries such as new generation communication technology, heat transfer devices, electronic components of novel power systems and the like, and rapid development of the information technology industry puts higher demands on high efficiency and high stability of dissimilar metal welded structural members. However, dissimilar metals have large differences in intrinsic physical properties such as thermal conductivity, linear expansion coefficient, melting point, etc., making it difficult to obtain high-performance welded joints. For a long time, the weld interface reaction products of dissimilar metals have been brittle intermetallic compounds (INTERMETALLIC COMPOUND, IMC). External stress, temperature cycle and other factors can lead to stress concentration of the IMC layer, thereby promoting initiation and expansion of microcracks and finally leading to failure of welding spots. The interfacial reaction produces thin (< 10 μm) and uniform IMC that is the basis for improved solder joint performance, while excessively thick or non-uniform IMC layers are detrimental to the improvement of solder joint performance. Therefore, a great deal of researches are performed to improve different substrate systems, add trace alloy elements into solder, develop different welding processes and the like so as to regulate and control the types, the distribution and the morphology of the IMC layer, further improve the service performance of the dissimilar welding joint, but the improvement effect is not obvious. The welding interface can generate a product with good plasticity and toughness instead of hard and brittle IMC, so that the problem of easy stress concentration in an interface IMC layer can be fundamentally solved, and the mechanical property of the welding interface is obviously improved. Research and development of high-entropy alloy provide a feasible thought for improving the toughness of interface reaction products, compared with a common single-main-component alloy system, when main components in the alloy are more and the content of each main component is similar, the random mixed entropy of system atoms is remarkably increased, and the high mixed entropy leads the system to tend to generate a solid solution with a simple structure (such as FCC or BCC structure), namely the high-entropy alloy rather than an IMC phase. In other words, when the high-entropy alloy substrate is welded with other metals by adopting a proper welding process, the multi-main-component system and the dissimilar metals are mutually fused, and the high-entropy interface reaction product is hopeful to be generated. The high-entropy product can release stress through local deformation, stress concentration of a welding interface in service is relieved, crack initiation and expansion are restrained, and mechanical properties of welding spots are greatly improved. However, at present, the research on the high entropy effect of the welding interface still lacks systematic reports in other welding processes, whether the brazing interface reaction product of dissimilar metals can realize high entropy, and whether the related problems of stress concentration, crack initiation, expansion and the like of the welding interface in service can be effectively relieved still needs to be further researched. Disclosure of Invention In view of the above, the invention provides a high-entropy alloy-heat-resistant steel dissimilar alloy with high entropy of a brazing interface and a welding method thereof. The high-entropy alloy is smelted and prepared, is machined into a plate through a large deformation cold rolling process, and is subjected to dissimilar metal brazing treatment with the high-strength martensitic heat-resistant steel plate, so that a brazing interface generates a single-phase solid solution with a simple structure instead of a traditional brittle hard IMC phase by means of high mixed entropy of the high-entropy alloy, and the high entropy of a welding interface can effectively relieve stress concentration, crack initiation and expansion and greatly improve the mechanical property of a welding spot. In order to achieve the above object, the present invention is realized by the follo