High-temperature brazing connection method for graphite and stainless steel

A connection method, stainless steel technology, applied in the connection of graphite and stainless steel, high temperature brazing connection of graphite and stainless steel, can solve the problems of thermal expansion coefficient mismatch and wettability, reduce residual stress and deformation, reduce cracking effect of inclination

Active Publication Date: 2021-04-09
XIANGTAN UNIV +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] The present invention provides a vacuum brazing process for graphite and stainless steel, aiming at the

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0019] Brazing connection of isostatic graphite and 304 stainless steel with 50 micron thick amorphous BNi82CrSiB brazing filler metal foil and 10 micron thick pure Cu foil as interlayer:

[0020] (1) Pretreatment: Put the stainless steel, isostatic graphite, amorphous BNi82CrSiB solder foil, and Cu foil polished with 400#, 600#, and 800# sandpaper into an alcohol solution for ultrasonic cleaning for 20 minutes. Then rinse with deionized water and dry for later use.

[0021] (2) Assembly: Put amorphous BNi82CrSiB solder foil, Cu foil, and amorphous BNi82CrSiB solder foil between the stainless steel and graphite surfaces to be welded in sequence to form a "sandwich" sandwich structure—stainless steel / non-crystalline Crystalline BNi82CrSiB solder foil / Cu foil / amorphous BNi82CrSiB solder foil / graphite, fix the welded structure and place it in a vacuum furnace.

[0022] (3) Brazing: The vacuum degree during the brazing process is better than 2×10 -3 Pa, heat up to 1180°C at a ra...

Embodiment 2

[0026] Brazing connection of isostatic graphite and 316L stainless steel with 30 micron thick amorphous BNi82CrSiB brazing filler metal foil and 40 micron thick pure Cu foil as interlayer:

[0027] (1) Pretreatment: Put the stainless steel, isostatic graphite, amorphous BNi82CrSiB solder foil, and Cu foil polished with 600#, 800#, and 1000# sandpaper into an alcohol solution for ultrasonic cleaning for 40 minutes, Then rinse with deionized water and dry for later use.

[0028] (2) Assembly: Put amorphous BNi82CrSiB solder foil, Cu foil, and amorphous BNi82CrSiB solder foil between the stainless steel and graphite surfaces to be welded in sequence to form a "sandwich" sandwich structure—stainless steel / non-crystalline Crystalline BNi82CrSiB solder foil / Cu foil / amorphous BNi82CrSiB solder foil / graphite, fix the welded structure and place it in a vacuum furnace.

[0029] (3) Brazing: The vacuum degree during the brazing process is better than 2×10 -3 Pa, heat up to 1040°C at a ...

Embodiment 3

[0033] Brazing connection of isostatic graphite and 304 stainless steel with 40 micron thick amorphous BNi82CrSiB brazing filler metal foil and 20 micron thick pure Cu foil as interlayer:

[0034] (1) Pretreatment: Put the stainless steel, isostatic graphite, amorphous BNi82CrSiB solder foil, and Cu foil polished with 600#, 800#, and 1000# sandpaper into an alcohol solution for ultrasonic cleaning for 40 minutes, Then rinse with deionized water and dry for later use.

[0035](2) Assembly: Put amorphous BNi82CrSiB solder foil, Cu foil, and amorphous BNi82CrSiB solder foil between the stainless steel and graphite surfaces to be welded in sequence to form a "sandwich" sandwich structure—stainless steel / non-crystalline Crystalline BNi82CrSiB solder foil / Cu foil / amorphous BNi82CrSiB solder foil / graphite, fix the welded structure and place it in a vacuum furnace.

[0036] (3) Brazing: The vacuum degree during the brazing process is better than 2×10 -3 Pa, heat up to 1140°C at a ra...

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Abstract

The invention relates to a high-temperature brazing connection method for graphite and stainless steel. The high-temperature brazing connection method for the graphite and the stainless steel comprises the following steps of selecting an amorphous brazing filler metal foil and a plastic metal foil as brazing materials; using cleaned graphite, stainless steel, amorphous brazing filler metal foil and plastic metal foil to form a graphite/amorphous brazing filler metal foil/plastic metal foil/amorphous brazing filler metal foil/stainless steel sandwich structure; and placing the structure in a vacuum furnace, increasing the temperature to 1040 to 1180 DEG C at the speed of 5 to 10 DEG C/min, conducting heat preservation for 30 to 90 min, conducting brazing connection, and then conducting sectional heat preservation and slow cooling to the room temperature. The high-temperature brazing connection method for the graphite and the stainless steel provided by the invention effectively solves the problems of serious mismatching and wettability of the thermal expansion coefficients of the graphite and the stainless steel, is beneficial to greatly reducing the residual stress of a joint and avoiding the formation of cracks, and realizes good connection between the graphite and the stainless steel.

Description

technical field [0001] The invention relates to the connection of graphite and stainless steel, specifically a high-temperature brazing connection method of graphite and stainless steel, which belongs to the field of material connection. Background technique [0002] Graphite is a new type of high-strength material with good chemical stability at room temperature, high melting point, excellent corrosion resistance, compressive strength, high thermal conductivity, and low relative density. It is widely used in defense industry, Aerospace, energy and transportation industries. Stainless steel, especially austenitic stainless steel, has good mechanical properties and process properties, good corrosion resistance and high strength, and is a metal material widely used in petroleum, chemical, fertilizer and other industrial sectors. The connectors of graphite and stainless steel are expected to have the advantages of both, and have broad development prospects in national defense ...

Claims

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Application Information

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IPC IPC(8): B23K1/008B23K1/20
CPCB23K1/008B23K1/20B23K1/206
Inventor 吴靓胡忠淇肖逸锋李淳钱锦文张汭陈燕
Owner XIANGTAN UNIV
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