CN112453622B - Vacuum brazing method for stainless heat-resistant steel pipe parts - Google Patents

Vacuum brazing method for stainless heat-resistant steel pipe parts Download PDF

Info

Publication number
CN112453622B
CN112453622B CN202011376708.9A CN202011376708A CN112453622B CN 112453622 B CN112453622 B CN 112453622B CN 202011376708 A CN202011376708 A CN 202011376708A CN 112453622 B CN112453622 B CN 112453622B
Authority
CN
China
Prior art keywords
filler metal
brazing
brazing filler
flow
vacuum
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN202011376708.9A
Other languages
Chinese (zh)
Other versions
CN112453622A (en
Inventor
王祥
贺振宇
张军
呼新岗
杨红茹
王晨
张建伟
王健
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
AECC Aviation Power Co Ltd
Original Assignee
AECC Aviation Power Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by AECC Aviation Power Co Ltd filed Critical AECC Aviation Power Co Ltd
Priority to CN202011376708.9A priority Critical patent/CN112453622B/en
Publication of CN112453622A publication Critical patent/CN112453622A/en
Application granted granted Critical
Publication of CN112453622B publication Critical patent/CN112453622B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • 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
    • B23K1/00—Soldering, e.g. brazing, or unsoldering
    • B23K1/008—Soldering within a furnace
    • 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
    • B23K1/00—Soldering, e.g. brazing, or unsoldering
    • B23K1/20—Preliminary treatment of work or areas to be soldered, e.g. in respect of a galvanic coating
    • 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
    • B23K1/00—Soldering, e.g. brazing, or unsoldering
    • B23K1/20—Preliminary treatment of work or areas to be soldered, e.g. in respect of a galvanic coating
    • B23K1/206—Cleaning

Abstract

The invention relates to the technical field of vacuum brazing, and particularly discloses a vacuum brazing method for stainless heat-resistant steel pipe partsDuring material preparation, after the preset brazing filler metal is finished, coating a flow resisting agent A and a flow resisting agent B, starting to heat up after the coating is finished, and performing vacuum brazing on the part after the heating is finished; the flow inhibitor A is prepared from Al2O3White flow resisting agent prepared from micro powder and water-based adhesive; the flow inhibitor B is pink flow inhibitor prepared from red flow inhibitor with the brand number of NICROBRAZ and green flow inhibitor with the brand number of NICROBRAZ; when the gold-based brazing filler metal is adopted, after the brazing filler metal is preset, the temperature is increased to 900 ℃ at the heating rate of 570-630 ℃/h, and the temperature is kept for 15-20 min; and then heating to 1010 ℃ at the heating rate of 390-510 ℃/h, preserving the heat for 10-15 min, and carrying out vacuum brazing on the parts. Solves the problems that the existing flow resisting agent preparation and coating scheme can not effectively inhibit the spreading of the copper-based brazing filler metal so as to cause brazing filler metal overflow and stacking height, and the heat preservation time is too long when the copper-based brazing filler metal is adopted for vacuum brazing so as to cause the growth of base metal crystal grains.

Description

Vacuum brazing method for stainless heat-resistant steel pipe parts
Technical Field
The invention relates to the technical field of vacuum brazing, and particularly discloses a vacuum brazing method for stainless heat-resistant steel pipe parts.
Background
The aeroengine is a heavy device in China and is known as 'bright pearl on industrial crown'. The vacuum brazing technology is widely applied to the field of manufacturing of aircraft engines, and has the characteristics of high production efficiency, small thermal deformation and the like. In the prior art, copper-based brazing filler metal represented by HBCuA brazing filler metal is often used for welding stainless heat-resistant steel pipe parts. On one hand, the copper-based brazing filler metal is corrosion-resistant, good in wettability and low in use cost, but most of the copper-based brazing filler metals need to be used for welding parts at the brazing temperature of over 1100 ℃, and the heat preservation time at the temperature is too long, so that the growth of base metal grains can be caused, and the mechanical property of a welding joint is influenced. On the other hand, the copper-based brazing filler metal has excessively strong activity and is very easy to spread on the surface of base materials such as stainless heat-resistant steel, and therefore a flow-resisting agent is required to be adopted to protect the non-brazing surface. The flow inhibitor is a liquid mixture of metal oxides, has large surface tension, is not beneficial to wetting and spreading of the brazing filler metal on the surface of the brazing filler metal, and can protect the non-brazing surface. In actual production, the existing common flow inhibitor cannot effectively inhibit the spreading of the copper-based brazing filler metal, so huge manpower and material resources are needed to be consumed to clean the overflow and the stacking height of the brazing filler metal on the surface of a part after welding.
Disclosure of Invention
The invention aims to provide a vacuum brazing method for stainless heat-resistant steel pipe parts, which solves the problems that the existing flow inhibitor cannot effectively inhibit the spreading of copper-based brazing filler metal so as to cause brazing filler metal overflow and stacking height, and the crystal grains of a base metal grow up due to overlong heat preservation time when the copper-based brazing filler metal is adopted for vacuum brazing.
The invention is realized by the following technical scheme:
a vacuum brazing method for stainless heat-resistant steel pipe parts comprises selecting copper-based brazing filler metal or gold-based brazing filler metal;
when the copper-based brazing filler metal is adopted, after the brazing filler metal is preset, coating a flow resisting agent A and a flow resisting agent B, starting to heat after the coating is finished, and performing vacuum brazing on the part after the heating is finished; wherein the flow inhibitor A is Al2O3Micro powder and water-based adhesive; the flow inhibitor B is prepared from red flow inhibitor with the brand of NICROBRAZ and green flow inhibitor with the brand of NICROBRAZ;
when the gold-based brazing filler metal is adopted, after the brazing filler metal is preset, the temperature is increased to 900 ℃ at the heating rate of 570-630 ℃/h, and the temperature is kept for 15-20 min; and then heating to 1010 ℃ at the heating rate of 390-510 ℃/h, preserving the heat for 10-15 min, and carrying out vacuum brazing on the parts.
Further, when the copper-based brazing filler metal is adopted, the temperature rise process is as follows: firstly, heating to 950 ℃ at a heating rate of 890-950 ℃ per hour, and preserving heat for 10-15 min; then heating to 1115 ℃ at the heating rate of 870-930 ℃ per hour, and keeping the temperature for 3-5 min.
Further, during the vacuum brazing process, the cold state vacuum degree is less than 4 multiplied by 10-2Pa, working vacuum degree less than 4X 10- 2Pa。
Further, the preparation method of the flow inhibitor A comprises the following steps: pouring water-based adhesive into Al2O3Stirring the micro powder for 1 to 3 minutes until the micro powder is uniform to obtain a white flow inhibitor A;
wherein, Al2O3The volume ratio of the micro powder to the water-based adhesive is (1-1.5): 1.
Further, the preparation method of the flow inhibitor B comprises the following steps: mixing a red flow inhibitor with the grade of NICROBRAZ and a green flow inhibitor with the grade of NICROBRAZ, and stirring for 1-3 minutes until the mixture is uniform to obtain a pink flow inhibitor B;
wherein the volume ratio of the red flow inhibitor to the green flow inhibitor is (1-2) to 1.
Furthermore, the flow resisting agent A is coated on the spherical surface of the ball head, and the flow resisting agent B is coated on the step surface of the ball head near the brazing seam to be welded and the step surface of the ball head at the back side of the brazing seam to be welded.
Further, before presetting the brazing filler metal, the part is pretreated, and the method comprises the following steps:
s1, positioning and welding;
s2, grinding the surface of the part;
and S3, cleaning the part to be welded.
Further, step S1 specifically includes: positioning the pipe on the ball head in a mode of uniformly positioning 1-2 points in the circumferential direction by argon arc welding, and ensuring that the brazing gap between the pipe and the ball head is 0.03-0.1 mm;
step S2 specifically includes: and (5) polishing the oxide film of the argon arc welding positioning welding spot and polishing the surface of the part until the metal luster is exposed.
Further, the preset brazing filler metal is specifically as follows: winding the filamentous brazing filler metal on a core rod with the same diameter as the pipe to form a ring, then shearing the brazing filler metal to form a brazing filler metal ring with one or more circumferences, and leveling;
cleaning and airing the brazing filler metal ring, placing the brazing filler metal ring on a part to be brazed of the argon arc welding positioning welding spot, and then bonding and positioning the brazing filler metal ring by using metal glue or positioning the brazing filler metal ring by using energy storage spot welding.
Further, after brazing the completion, clear up the part, the clearance process includes: blowing off the flow resisting agent A by using compressed air, and removing the flow resisting agent B by using acetone;
cleaning the residual blocking agent marks by using sand paper or scouring pad;
if the brazing filler metal splashes, overflows or is piled up on the surface of the part, the brazing filler metal is removed in a mechanical grinding mode.
Compared with the prior art, the invention has the following beneficial technical effects:
the invention discloses a vacuum brazing method for stainless heat-resistant steel pipe parts, which effectively inhibits the spreading of copper-based brazing filler metal by smearing two self-prepared flow resisting agents when the copper-based brazing filler metal is adopted, and the flow resisting agents can be easily removed after welding, thereby greatly reducing the labor intensity for cleaning the parts after welding and improving the production efficiency. The two self-prepared flow resisting agents are also suitable for other parts welded by copper-based brazing filler metals, and have great popularization value; compared with the copper-based brazing filler metal, the gold-based brazing filler metal has the advantages that the strength is high, the plasticity of a formed welding joint is good, more importantly, the melting point is proper, the growth of base metal grains is not easy to cause, and the quality of a formed brazing welding line is good even if a flow resisting agent is not coated.
Furthermore, by optimizing the technological parameters of vacuum brazing of the copper-based brazing filler metal and adopting a faster heating rate and shorter brazing heat preservation time, the growth degree of the crystal grains of the base metal is reduced.
Drawings
FIG. 1 is a schematic view showing the structure of a stainless steel pipe of a heat-resistant type;
FIG. 2 is a flow chart of the present invention;
FIG. 3 is a metallographic photograph of a brazed joint after vacuum brazing of a part with a gold-based brazing filler metal.
Wherein, 1 is a ball head, 2 is a tube, 3 is a spherical surface, 4 is a ball head step surface, and 5 is a brazing ring.
Detailed Description
The present invention will now be described in further detail with reference to specific examples, which are intended to be illustrative, but not limiting, of the invention.
The invention discloses a vacuum brazing method for stainless heat-resistant steel pipe parts, which can select copper-based brazing filler metal or gold-based brazing filler metal.
When the copper-based brazing filler metal is adopted, after the brazing filler metal is preset, the flow resisting agent A and the flow resisting agent B are coated, the temperature is raised after the coating is finished, and the parts are subjected to vacuum brazing after the temperature is raised. The heating rate in the prior art is increased from 650 ℃/h to 890-950 ℃/h, and the heating rate is increased from 450 ℃/h to 870-930 ℃/h. The heat preservation time of 7-13 min at the soldering temperature of 1115 ℃ in the prior art is shortened to 3-5 min. See, in particular, examples one through five.
Example one
In this embodiment, wire-shaped HBCuA brazing filler metal is used to vacuum braze stainless heat-resistant steel pipe parts composed of 0Cr18Ni9 pipe 2 and 4Cr14Ni14W2Mo bulb 1, as shown in fig. 2, which specifically includes the following steps:
(1) pretreatment:
step 1, positioning welding: the method comprises the steps of positioning a pipe 2 on a ball head 1 in a mode of circumferentially and uniformly positioning 1-2 points by argon arc welding, and then guaranteeing that a brazing gap between the pipe 2 and the ball head 1 meets 0.03-0.1 mm by clamping.
Step 2, polishing: and (3) polishing and polishing the oxide film of the argon arc welding positioning welding spot by using a steel wire wheel or a steel wire brush, and polishing the surface of the part by using abrasive paper or scouring pad until fresh metallic luster is exposed.
Step 3, cleaning: and (4) dipping clean silk cloth into clean acetone to scrub the part to be welded until the silk cloth does not have stains.
(2) Presetting brazing filler metal: winding the filamentous HBCuA brazing filler metal with the diameter of phi 1mm on a core rod with the diameter of phi 6mm to form a ring, then shearing the brazing filler metal by using an inclined jaw clamp to form a brazing filler metal ring 5 with a circumference, and manually leveling. Cleaning the brazing filler metal ring 5 with clean acetone, naturally drying, placing the brazing filler metal ring on a part to be brazed of the argon arc welding positioning welding point, as shown in the attached drawing 1, and then bonding and positioning the brazing filler metal ring with metal glue.
(3) Coating a flow resisting agent: mixing Al2O3Adding the micro powder and the water-based adhesive into a beaker according to the volume ratio of 1:1 respectively, and pouring the water-based adhesive into Al2O3Repeatedly stirring in the fine powder (1)And about 3) minutes till the mixture is uniform, and then the white flow resisting agent A can be prepared. In addition, the red flow inhibitor with the brand of NICROBRAZ and the green flow inhibitor with the brand of NICROBRAZ are respectively added into a beaker according to the volume ratio of 1:1, and then are mixed and stirred for 1-3 minutes until the mixture is uniform, so that the pink flow inhibitor B can be prepared. The process test result shows that compared with the flow inhibitor A, the flow inhibitor B has better effect of inhibiting the melting and spreading of the copper-based brazing filler metal, and the flow inhibitor A is more convenient to clean after welding. Therefore, referring to fig. 1, the flow inhibitor a is applied to the spherical surface 3 of the ball head 1 by using a writing brush or a brush pen, so as to prevent solder from splashing and overflowing to weld the ball head and a ball head seat (not shown in the figure) assembled with the ball head, ensure that the ball head seat can freely rotate in an allowed space after welding, and meanwhile, the flow inhibitor a can be blown off by compressed air, so that residual marks are not easy to leave; the flow inhibitor B is coated on the step surface 4 of the ball head near the soldering seam to be welded by a writing brush or a line brush, so as to prevent copper-based brazing filler metal from spreading on the step surface of the ball head, force the brazing filler metal to flow into a gap to be welded and ensure the welding quality; and the flow resisting agent B is coated on the ball head step surface 4 on the back side of the soldering joint to be welded by using a writing brush or a brush bank, so that the molten liquid brazing filler metal in the welding process is prevented from overflowing on the back side of the soldering joint to be welded beyond the gap to be welded to influence the later assembly of the part. The smearing methods of the second and third embodiments are the same, and are not described again.
(4) Vacuum brazing: and flatly placing the prepared pipe parts on a charging basket or a material rack paved with a ceramic plate for charging. Before entering the furnace, the solder ring 5 is checked to be fixed and stable, and the flow resisting agent is smeared in place. The cold state vacuum degree in the vacuum brazing process is less than 4 multiplied by 10-2Pa, working vacuum degree should be less than 4 × 10-2Pa. Heating to 950 ℃ at a heating rate of 920 ℃/h, and keeping the temperature for 13 min. Then heating to 1115 ℃ at the heating rate of 900 ℃/h, and preserving heat for 5 min. Finally, cooling to below 1000 ℃ in vacuum, backfilling with argon, cooling to below 100 ℃ by using argon and a fan, and discharging.
Post-weld treatment, comprising the following steps:
cleaning parts: the white flow inhibitor is blown off by compressed air, and the pink flow inhibitor is dipped in acetone by a brush to be removed. And cleaning the residual blots of the flow resisting agent by using sand paper or scouring pad. The problems of solder splashing, overflow, stacking and the like hardly exist on the surface of the part.
And (3) checking the quality of the welding seam: and (4) inspecting the quality of the vacuum brazing welding seam of the stainless heat-resistant steel pipe subclass part according to relevant vacuum brazing quality acceptance standards. And (3) adding a proper amount of filamentous HBCuA brazing filler metal into the parts with the defects of cavities, non-welded joints and the like on the brazing welding seams in a mode of bonding and positioning the parts by using metal glue at the positions needing repair welding, and repeating the steps (2) to (4). The part is allowed to be repair welded at most twice.
As a result: by coating two self-prepared flow resisting agents, the spreading of the copper-based brazing filler metal is effectively inhibited, the flow resisting agents can be easily removed after welding, the labor intensity of cleaning parts after welding is greatly reduced, and the production efficiency is improved.
The verification proves that the grain size of the base metal is detected to be (3-2) grade after vacuum brazing.
After the vacuum brazing in the prior art is adopted, the grain size of a base metal is detected to be 2-1 grade, (1-4) grade is coarse grains, and (5-8) grade is fine grains. Generally, the finer the grains, the better the overall mechanical properties of the material. Therefore, the crystal grains of the base material of the embodiment are improved, and the comprehensive mechanical property of the base material is ensured.
Example two
Different from the first embodiment, Al2O3Adding the micro powder and the water-based adhesive into a beaker according to the volume ratio of 1.5:1 respectively, and pouring the water-based adhesive into Al2O3And repeatedly stirring (1-3) the mixture in the micro powder for uniform stirring to prepare a white flow inhibitor A.
The verification proves that the grain size of the base metal is detected to be (3-2) grade after vacuum brazing. Therefore, the crystal grains of the base material of the embodiment are improved, and the comprehensive mechanical property of the base material is ensured.
EXAMPLE III
The embodiment adopts filiform HBCuA brazing filler metal to braze a stainless heat-resistant steel pipe part consisting of a 0Cr18Ni9 pipe 2 and a 4Cr14Ni14W2Mo ball head 1 in vacuum, and specifically comprises the following steps:
(1) pretreatment:
step 1, tack welding: the method comprises the steps of positioning a pipe 2 on a ball head 1 in a mode of circumferentially and uniformly positioning 1-2 points by argon arc welding, and then guaranteeing that a brazing gap between the pipe 2 and the ball head 1 meets 0.03-0.1 mm by clamping.
Step 2, polishing: and (3) polishing and polishing the oxide film of the argon arc welding positioning welding spot by using a steel wire wheel or a steel wire brush, and polishing the surface of the part by using abrasive paper or scouring pad until fresh metallic luster is exposed.
Step 3, cleaning: and (4) dipping clean silk cloth into clean acetone to scrub the part to be welded until the silk cloth does not have stains.
(2) Presetting brazing filler metal: winding the filamentous HBCuA brazing filler metal with the diameter of phi 1mm on a core rod with the diameter of phi 6mm to form a ring, then shearing the brazing filler metal by using an inclined jaw clamp to form a brazing filler metal ring 5 with a circumference, and manually leveling. Cleaning the solder ring 5 with clean acetone, naturally drying, placing at the position to be soldered of the argon arc welding positioning solder joint, as shown in figure 1, and bonding and positioning with metal glue.
(3) Coating a flow resisting agent: mixing Al2O3Adding the micro powder and the water-based adhesive into a beaker according to the volume ratio of 1:1 respectively, and pouring the water-based adhesive into Al2O3And repeatedly stirring (1-3) the mixture in the micro powder for uniform stirring to prepare a white flow inhibitor A. In addition, the red flow inhibitor with the brand of NICROBRAZ and the green flow inhibitor with the brand of NICROBRAZ are respectively added into a beaker according to the volume ratio of 2:1, and then are mixed and stirred for 1-3 minutes until the mixture is uniform, so that the pink flow inhibitor B can be prepared. Referring to the attached drawing 1, the flow inhibitor A is coated on the spherical surface 3 of the ball head 1 by a writing brush or a line brush, and the flow inhibitor B is coated on the ball head step surface 4 near the soldering joint to be soldered and the ball head step surface 4 at the back side of the soldering joint to be soldered by a writing brush or a line brush respectively.
(4) Vacuum brazing: and flatly placing the prepared pipe parts on a charging basket or a material rack paved with a ceramic plate for charging. Before entering the furnace, the solder ring 5 is fixed firmly and stably, and the flow resisting agent is smeared in place. The cold state vacuum degree in the vacuum brazing process is less than 4 multiplied by 10-2Pa, working vacuum degree should be less than 4 × 10-2Pa. Firstly, heating to 950 ℃ at a heating rate of 950 ℃/h, and preserving heat for 10 min. Then heating to 1115 ℃ at the heating rate of 930 ℃/h, and preserving the heat for 3 min. Finally, cooling to below 1000 ℃ in vacuum, backfilling with argon, cooling to below 100 ℃ by using argon and a fan, and discharging.
Post-weld treatment, comprising the following steps:
cleaning parts: the white flow inhibitor is blown off by compressed air, and the pink flow inhibitor is dipped in acetone by a brush to be removed. And cleaning the residual blots of the flow resisting agent by using sand paper or scouring pad. The problems of solder splashing, overflow, stacking and the like hardly exist on the surface of the part.
And (3) checking the quality of the welding seam: and (4) inspecting the quality of the vacuum brazing welding seam of the stainless heat-resistant steel pipe subclass part according to relevant vacuum brazing quality acceptance standards. And (3) adding a proper amount of filamentous HBCuA brazing filler metal into the parts with the defects of cavities, non-welded joints and the like on the brazing welding seams in a mode of bonding and positioning the parts by using metal glue at the positions needing repair welding, and repeating the steps (2) to (4). The part is allowed to be repair welded at most twice.
As a result: the verification proves that the grain size of the base metal detected after vacuum brazing is of the grade (4-3), which is better than that of the first embodiment. As a preferred item of the first embodiment, the second embodiment reduces the growth degree of the crystal grains of the base material by increasing the temperature rise rate and shortening the holding time at the brazing temperature. The effect of the flow inhibitor is the same as that of the first embodiment, and is not described in detail.
Example four
In contrast to the second example, Al is added2O3Adding the micro powder and the water-based adhesive into a beaker according to the volume ratio of 1.3:1, and pouring the water-based adhesive into Al2O3And repeatedly stirring (1-3) the mixture in the micro powder for uniform stirring to prepare a white flow inhibitor A.
Verification shows that the grain size of the base metal is detected to be (4-3) grade after vacuum brazing, and the growth degree of the base metal grains is reduced. The effect of the flow inhibitor is the same as that of the first embodiment, and is not described in detail.
EXAMPLE five
The same pretreatment and post-treatment steps as in example one are not described again here.
The embodiment adopts filiform HBCuA brazing filler metal to braze a stainless heat-resistant steel pipe part consisting of a 0Cr18Ni9 pipe 2 and a 4Cr14Ni14W2Mo ball head 1 in vacuum, and specifically comprises the following steps:
presetting brazing filler metal: winding the filamentous HBCuA brazing filler metal with the diameter of phi 1mm on a core rod with the diameter of phi 6mm to form a ring, then shearing the brazing filler metal by using an inclined jaw clamp to form a brazing filler metal ring 5 with a circumference, and manually leveling. Cleaning the solder ring 5 with clean acetone, naturally drying, placing at the position to be soldered of the argon arc welding positioning solder joint, as shown in figure 1, and bonding and positioning with metal glue.
Coating a flow resisting agent: mixing Al2O3Adding the micro powder and the water-based adhesive into a beaker according to the volume ratio of 1:1 respectively, and pouring the water-based adhesive into Al2O3And repeatedly stirring (1-3) the mixture in the micro powder for uniform stirring to prepare a white flow inhibitor A. In addition, the red flow inhibitor with the brand of NICROBRAZ and the green flow inhibitor with the brand of NICROBRAZ are respectively added into a beaker according to the volume ratio of 1.5:1, and then are mixed and stirred for 1-3 minutes until the mixture is uniform, so that the pink flow inhibitor B can be prepared. Referring to the attached drawing 1, the flow inhibitor A is coated on the spherical surface 3 of the ball head 1 by a writing brush or a line brush, and the flow inhibitor B is coated on the ball head step surface 4 near the soldering joint to be soldered and the ball head step surface 4 at the back side of the soldering joint to be soldered by a writing brush or a line brush respectively.
Vacuum brazing: and flatly placing the prepared pipe parts on a charging basket or a material rack paved with a ceramic plate for charging. Before entering the furnace, the solder ring 5 is fixed firmly and stably, and the flow resisting agent is smeared in place. The cold state vacuum degree in the vacuum brazing process is less than 4 multiplied by 10-2Pa, working vacuum degree should be less than 4 × 10-2Pa. Firstly, the temperature is raised to 950 ℃ at the heating rate of 890 ℃/h, and the temperature is kept for 15 min. Then the temperature is increased to 1115 ℃ at the heating rate of 870 ℃/h, and the temperature is kept for 4 min. Finally, cooling to below 1000 ℃ in vacuum, backfilling with argon, cooling to below 100 ℃ by using argon and a fan, and discharging.
As a result: the verification proves that the grain size of the base metal detected after vacuum brazing is about 3 grades, and compared with the grain size of the base metal detected after vacuum brazing in the prior art which is 2-1 grades, the grain growth degree of the base metal is reduced. The effect of the flow inhibitor is the same as that of the first embodiment, and is not described in detail.
When the gold-based brazing filler metal is adopted, after the brazing filler metal is preset, the temperature is increased to 900 ℃ at the heating rate of (570-630) DEG C/h, and the temperature is kept for 15-20 min; and then heating to 1010 ℃ at the heating rate of 390-510 ℃/h, preserving the heat for 10-15 min, and carrying out vacuum brazing on the parts. Compared with copper-based solder, the gold-based solder has high strength, the formed welding joint has good plasticity, more importantly, the melting point is proper, and the growth of base metal crystal grains is not easy to cause. See examples six to eight.
EXAMPLE six
In the embodiment, a wire-shaped HBAu82Ni brazing filler metal is adopted to perform vacuum brazing on stainless heat-resistant steel pipe parts consisting of a 0Cr18Ni9 pipe 2 and a 4Cr14Ni14W2Mo ball head 1, and the vacuum brazing method specifically comprises the following steps:
(1) pretreatment:
step 1, tack welding: the method comprises the steps of positioning a pipe 2 on a ball head 1 in a mode of circumferentially and uniformly positioning 1-2 points by argon arc welding, and then guaranteeing that a brazing gap between the pipe 2 and the ball head 1 meets 0.03-0.1 mm by clamping.
Step 2, polishing: and (3) polishing and polishing the oxide film of the argon arc welding positioning welding spot by using a steel wire wheel or a steel wire brush, and polishing the surface of the part by using abrasive paper or scouring pad until fresh metallic luster is exposed.
Step 3, cleaning: and (4) dipping clean silk cloth into clean acetone to scrub the part to be welded until the silk cloth does not have stains.
(2) Presetting brazing filler metal: the HBAu82Ni brazing filler metal with the diameter phi of 0.7mm is wound on a core rod with the diameter phi of 6mm to be made into a ring shape, then the brazing filler metal is cut off by using an inclined jaw pliers to be made into a brazing filler metal ring 5 with two circumferences, and the brazing filler metal ring is manually leveled. Cleaning the solder ring 5 with clean acetone, naturally drying, placing at the position to be soldered of the argon arc welding positioning solder joint, as shown in figure 1, and positioning by energy storage spot welding.
(3) Vacuum brazing: and flatly placing the prepared pipe parts on a charging basket or a material rack paved with a ceramic plate for charging. Solder ring for inspection before furnace entering5, fixing and stabilizing, and smearing the flow resisting agent in place. The cold state vacuum degree in the vacuum brazing process is less than 4 multiplied by 10-2Pa, working vacuum degree should be less than 4 × 10-2Pa. The temperature is raised to 900 ℃ at the heating rate of 600 ℃/h, and the temperature is kept for 17 min. Then the temperature is raised to 1010 ℃ at the heating rate of 450 ℃/h, and the temperature is kept for 13 min. Finally, cooling to below 900 ℃ in vacuum, backfilling with argon, cooling to below 100 ℃ by using argon and a fan, and discharging.
And (3) post-welding treatment, which is mainly used for checking the quality of a welding seam: and (4) inspecting the quality of the vacuum brazing welding seam of the stainless heat-resistant steel pipe subclass part according to relevant vacuum brazing quality acceptance standards. And (3) adding a proper amount of silk-shaped HBAu82Ni brazing filler metal into the parts with the defects of cavities, non-welded joints and the like on the brazing welding seams in an energy storage spot welding mode at the positions of the parts needing repair welding, and repeating the steps (2) to (3). The part is allowed to be repair welded at most twice.
EXAMPLE seven
In the embodiment, a wire-shaped HBAu82Ni brazing filler metal is adopted to perform vacuum brazing on stainless heat-resistant steel pipe parts consisting of a 0Cr18Ni9 pipe 2 and a 4Cr14Ni14W2Mo ball head 1, and the vacuum brazing method specifically comprises the following steps:
(1) pretreatment:
step 1, tack welding: the method comprises the steps of positioning a pipe 2 on a ball head 1 in a mode of circumferentially and uniformly positioning 1-2 points by argon arc welding, and then guaranteeing that a brazing gap between the pipe 2 and the ball head 1 meets 0.03-0.1 mm by clamping.
Step 2, polishing: and (3) polishing and polishing the oxidation film of the argon arc welding positioning welding spot by using a steel wire wheel or a steel wire brush, and polishing the surface of the part by using abrasive paper or scouring pad until fresh metal luster is exposed.
Step 3, cleaning: and (4) dipping clean silk cloth into clean acetone to scrub the part to be welded until the silk cloth does not have stains.
(2) Presetting brazing filler metal: the HBAu82Ni brazing filler metal with the diameter phi of 0.7mm is wound on a core rod with the diameter phi of 6mm to be made into a ring shape, then the brazing filler metal is cut off by using an inclined jaw pliers to be made into a brazing filler metal ring 5 with two circumferences, and the brazing filler metal ring is manually leveled. Cleaning the solder ring 5 with clean acetone, naturally drying, placing at the position to be soldered of the argon arc welding positioning solder joint, as shown in figure 1, and positioning by energy storage spot welding.
(3) Vacuum brazing: and flatly placing the prepared pipe parts on a charging basket or a material rack paved with a ceramic plate for charging. Before entering the furnace, the solder ring 5 is fixed firmly and stably, and the flow resisting agent is smeared in place. The cold state vacuum degree in the vacuum brazing process is less than 4 multiplied by 10-2Pa, working vacuum degree should be less than 4 × 10-2Pa. Heating to 900 ℃ at a heating rate of 570 ℃/h, and keeping the temperature for 15 min. Then the temperature is raised to 1010 ℃ at the heating rate of 390 ℃/h, and the temperature is kept for 10 min. Finally, vacuum cooling is carried out to below 900 ℃, argon is backfilled, and the argon and a fan are cooled to below 100 ℃ to be discharged.
The post-weld treatment is the same as in the sixth embodiment, and is not described again.
Example eight
In the embodiment, a wire-shaped HBAu82Ni brazing filler metal is adopted to perform vacuum brazing on stainless heat-resistant steel pipe parts consisting of a 0Cr18Ni9 pipe 2 and a 4Cr14Ni14W2Mo ball head 1, and the vacuum brazing method specifically comprises the following steps:
(1) pretreatment:
step 1, tack welding: the method comprises the steps of positioning a pipe 2 on a ball head 1 in a mode of circumferentially and uniformly positioning 1-2 points by argon arc welding, and then guaranteeing that a brazing gap between the pipe 2 and the ball head 1 meets 0.03-0.1 mm by clamping.
Step 2, polishing: and (3) polishing and polishing the oxide film of the argon arc welding positioning welding spot by using a steel wire wheel or a steel wire brush, and polishing the surface of the part by using abrasive paper or scouring pad until fresh metallic luster is exposed.
Step 3, cleaning: and (4) dipping clean silk cloth into clean acetone to scrub the part to be welded until the silk cloth does not have stains.
(2) Presetting brazing filler metal: the HBAu82Ni brazing filler metal with the diameter phi of 0.7mm is wound on a core rod with the diameter phi of 6mm to be made into a ring shape, then the brazing filler metal is cut off by using an inclined jaw pliers to be made into a brazing filler metal ring 5 with two circumferences, and the brazing filler metal ring is manually leveled. Cleaning the solder ring 5 with clean acetone, naturally drying, placing at the position to be soldered of the argon arc welding positioning solder joint, as shown in figure 1, and positioning by energy storage spot welding.
(3) Vacuum brazing: flattening the prepared pipe type partsPutting the mixture into a charging basket or a material rack paved with ceramic plates for charging. Before entering the furnace, the solder ring 5 is fixed firmly and stably, and the flow resisting agent is smeared in place. The cold state vacuum degree in the vacuum brazing process is less than 4 multiplied by 10-2Pa, working vacuum degree should be less than 4 × 10-2Pa. The temperature is raised to 900 ℃ at the heating rate of 630 ℃/h, and the temperature is kept for 20 min. Then the temperature is raised to 1010 ℃ at the heating rate of 510 ℃/h, and the temperature is kept for 15 min. Finally, cooling to below 900 ℃ in vacuum, backfilling with argon, cooling to below 100 ℃ by using argon and a fan, and discharging.
The post-weld treatment is the same as in the sixth embodiment, and is not described again.
Six to eight embodiments are verified, the grain sizes of the base metal detected after vacuum brazing are all 6 grades, the grain sizes of the base metal before welding are basically kept, and the mechanical properties of parts are guaranteed. Meanwhile, the gold-based brazing filler metal is insensitive to the requirement of the gap to be welded, and proper brazing filler metal amount is selected through early-stage process tests and is firmly positioned by adopting energy storage spot welding, so that the problems of brazing filler metal splashing, overflowing, stacking and the like hardly exist on the surface of a part even under the condition that a flow resisting agent is not coated. The parts are qualified in one-time welding, the production efficiency is greatly improved, a metallographic photograph of the position of a brazing welding line is shown in an attached drawing 3, and the quality of the welding line is good.

Claims (7)

1. A vacuum brazing method for stainless heat-resistant steel pipe parts is characterized in that copper-based brazing filler metal is selected;
after the preset brazing filler metal is finished, coating a flow resisting agent A and a flow resisting agent B, starting to heat up after the coating is finished, and carrying out vacuum brazing on the parts after the heating is finished; wherein the flow inhibitor A is Al2O3Micro powder and water-based adhesive; the flow inhibitor B is prepared from red flow inhibitor with the brand of NICROBRAZ and green flow inhibitor with the brand of NICROBRAZ;
the preparation method of the flow inhibitor A comprises the following steps: pouring water-based adhesive into Al2O3Stirring the micro powder for 1 to 3 minutes until the micro powder is uniform to obtain a white flow inhibitor A; wherein, Al2O3The volume ratio of the micro powder to the water-based adhesive is (1-1.5) to 1;
the preparation method of the flow inhibitor B comprises the following steps: mixing a red flow inhibitor with the grade of NICROBRAZ and a green flow inhibitor with the grade of NICROBRAZ, and stirring for 1-3 minutes until the mixture is uniform to obtain a pink flow inhibitor B; wherein the volume ratio of the red flow inhibitor to the green flow inhibitor is (1-2) to 1;
the flow resisting agent A is coated on the spherical surface (3) of the ball head (1), and the flow resisting agent B is coated on the ball head step surface (4) near the soldering seam to be welded and the ball head step surface (4) on the back side of the soldering seam to be welded.
2. The vacuum brazing method for stainless heat-resistant steel pipe parts according to claim 1, wherein the temperature rise process comprises the following steps: firstly, heating to 950 ℃ at a heating rate of 890-950 ℃ per hour, and preserving heat for 10-15 min; then heating to 1115 ℃ at the heating rate of 870-930 ℃ per hour, and keeping the temperature for 3-5 min.
3. The vacuum brazing method for parts of stainless heat-resistant steel pipe subclass as claimed in claim 1, wherein the degree of cold state vacuum is less than 4 x 10 during vacuum brazing-2Pa, working vacuum degree less than 4X 10-2Pa。
4. The vacuum brazing method for the stainless heat-resistant steel pipe subclass parts according to claim 1, characterized in that the parts are pretreated before being preset with brazing filler metal, comprising the following steps:
s1, positioning and welding;
s2, grinding the surface of the part;
and S3, cleaning the part to be welded.
5. The vacuum brazing method for stainless steel pipe or like parts according to claim 4, wherein step S1 comprises: positioning the pipe (2) on the ball head (1) by adopting a mode of uniformly positioning 1-2 points in the circumferential direction by argon arc welding, and ensuring that the brazing gap between the pipe (2) and the ball head (1) meets 0.03-0.1 mm;
step S2 specifically includes: and (5) polishing the oxide film of the argon arc welding positioning welding spot and polishing the surface of the part until the metal luster is exposed.
6. The vacuum brazing method for stainless heat-resistant steel pipe parts according to claim 1, wherein the preset brazing filler metal is specifically: winding the filiform brazing filler metal on a core rod with the same diameter as the pipe (2) to form a ring shape, then shearing the brazing filler metal to form a brazing filler metal ring (5) with one or more circumferences, and leveling;
the brazing ring (5) is cleaned and dried, is placed at the position to be brazed of the argon arc welding positioning welding spot, and is then bonded and positioned by metal glue or positioned by energy storage spot welding.
7. The vacuum brazing method for stainless steel pipe parts of heat-resistant class according to claim 1, wherein after the brazing is completed, the parts are cleaned, and the cleaning process comprises the following steps: blowing the flow resisting agent A by using compressed air, and removing the flow resisting agent B by using acetone;
cleaning the residual blocking agent marks by using sand paper or scouring pad;
if the brazing filler metal splashes, overflows or is piled up on the surface of the part, the brazing filler metal is removed in a mechanical grinding mode.
CN202011376708.9A 2020-11-30 2020-11-30 Vacuum brazing method for stainless heat-resistant steel pipe parts Active CN112453622B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202011376708.9A CN112453622B (en) 2020-11-30 2020-11-30 Vacuum brazing method for stainless heat-resistant steel pipe parts

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202011376708.9A CN112453622B (en) 2020-11-30 2020-11-30 Vacuum brazing method for stainless heat-resistant steel pipe parts

Publications (2)

Publication Number Publication Date
CN112453622A CN112453622A (en) 2021-03-09
CN112453622B true CN112453622B (en) 2022-05-10

Family

ID=74805711

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202011376708.9A Active CN112453622B (en) 2020-11-30 2020-11-30 Vacuum brazing method for stainless heat-resistant steel pipe parts

Country Status (1)

Country Link
CN (1) CN112453622B (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114871525A (en) * 2022-04-18 2022-08-09 成都四威高科技产业园有限公司 Pyramid horn antenna furnace brazing process

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2512763B2 (en) * 1987-08-29 1996-07-03 株式会社 徳力本店 Stop-off agent for brazing
WO2001083157A1 (en) * 2000-04-28 2001-11-08 Elliott Turbomachinery Co., Inc. Method of brazing and article made therefrom
CN101983819B (en) * 2010-11-04 2013-05-22 西安航空动力股份有限公司 Method and fixture for welding high temperature alloy and cupronickel
CN103298582B (en) * 2011-02-22 2015-09-02 三菱重工业株式会社 The manufacture method of impeller
CN202984862U (en) * 2012-10-30 2013-06-12 西安航空动力股份有限公司 Winding tool of gold based filiform brazing alloy
CN108098093B (en) * 2017-12-01 2020-04-03 温州宏丰电工合金股份有限公司 Flow resisting agent for stainless steel vacuum brazing
CN110919289B (en) * 2019-12-27 2021-08-17 华瑞（江苏）燃机服务有限公司 Brazing process for turbine stationary blade of gas turbine
CN111360351A (en) * 2020-03-05 2020-07-03 西安陕鼓动力股份有限公司 Process method for brazing Cr13 stainless steel impeller by Au-based brazing filler metal

Also Published As

Publication number Publication date
CN112453622A (en) 2021-03-09

Similar Documents

Publication Publication Date Title
KR102566105B1 (en) Method of repairing superalloys
CN102120292B (en) Vacuum brazing repairing method for cracks of high-temperature alloy thin-wall part
CN109848638B (en) High-temperature alloy composite repair method and repair material
CN103624353B (en) A kind of method for welding of DD5 single crystal alloy
JP3779727B2 (en) Repair coating of superalloy articles such as gas turbine engine components
CN102107306B (en) Repairing method for defects of turbine guide blade
EP0800889B1 (en) Nickel-base braze material
US20060117562A1 (en) Process for repairing turbine components
US5320690A (en) Process for repairing co-based superalloy using co-based brazing compositions
JP2009107020A (en) Braze formulation and process for making and using
JP2009285664A5 (en)
CN110405300B (en) Method for preparing high-strength AlCoCrFeNi high-entropy alloy joint by adopting Ni-based brazing filler metal
JPH11156559A (en) Welding method of hardenable nickel base alloy
CN112453622B (en) Vacuum brazing method for stainless heat-resistant steel pipe parts
MXPA06002698A (en) Method for repairing parts composed of superalloys.
CN108032033A (en) A kind of restorative procedure of turborotor cold air hole crackle
CN110369820B (en) Method for brazing Hastelloy N alloy by adopting Ni-Cr-W-B-Si-Fe brazing filler metal
CN114769772B (en) Vacuum brazing method for improving strength of GH3536/GH4738 alloy joint
CN110919289B (en) Brazing process for turbine stationary blade of gas turbine
CN108237280B (en) Welding method of copper-tungsten electrode
CN101274397B (en) Promoting agent for nickel-base high-temperature alloy TIG weld and method of use thereof
CN101992331B (en) Vacuum brazing process for super-Ni laminated material and Cr18-Ni8 stainless steel
CN110238503A (en) Ni-based middle layer alloy, preparation method and application and welding method
CN112077410A (en) Welding repair method for defects of 3D printed metal component
CN108237278B (en) welding method of copper-molybdenum electrode

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant