CN113732479A - Dissimilar metal diffusion bonding method for G115 heat-resistant steel and Inconel740 high-temperature alloy - Google Patents
Dissimilar metal diffusion bonding method for G115 heat-resistant steel and Inconel740 high-temperature alloy Download PDFInfo
- Publication number
- CN113732479A CN113732479A CN202110919299.0A CN202110919299A CN113732479A CN 113732479 A CN113732479 A CN 113732479A CN 202110919299 A CN202110919299 A CN 202110919299A CN 113732479 A CN113732479 A CN 113732479A
- Authority
- CN
- China
- Prior art keywords
- temperature
- heat
- furnace
- connection
- diffusion
- 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.)
- Granted
Links
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
- B23K20/00—Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating
- B23K20/02—Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating by means of a press ; Diffusion bonding
- B23K20/023—Thermo-compression bonding
- B23K20/026—Thermo-compression bonding with diffusion of soldering material
-
- 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
- B23K20/00—Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating
- B23K20/22—Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating taking account of the properties of the materials to be welded
-
- 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
- B23K20/00—Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating
- B23K20/24—Preliminary treatment
-
- 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
- B23K20/00—Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating
- B23K20/26—Auxiliary equipment
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Pressure Welding/Diffusion-Bonding (AREA)
Abstract
The invention provides a dissimilar metal diffusion bonding method of G115 heat-resistant steel and Inconel740(H) high-temperature alloy, which comprises the following steps: selecting Ni-Cr-Si-Co alloy as an intermediate layer, and placing the intermediate layer between the G115 heat-resistant steel and the Inconel740(H) high-temperature alloy for assembly to form a prefabricated body; putting the prefabricated body into a vacuum diffusion furnace, applying axial pressure of 0.2-0.5MPa, and pressing the prefabricated body tightly by an upper pressing head and a lower pressing head; closing the furnace door, starting to vacuumize the vacuum diffusion furnace, and when the vacuum degree of the diffusion furnace reaches 10‑2‑10‑3Heating is started when the pressure is Pa level; heating and warming; when the furnace temperature reaches the connection heat preservation temperature, applying connection pressure to the prefabricated body in the diffusion furnace, and then carrying outThe rows are diffusion bonded to form joints. According to the invention, the connecting temperature, the connecting pressure and the heat preservation time are reasonably designed, the type and the thickness of the Ni-Cr-Si-Co intermediate layer are reasonably selected, the cooling process after connection and the heat treatment process after connection are designed, the dissimilar metal joint with better performance is obtained, the normal-temperature mechanical property and the high-temperature mechanical property both reach more than 90% of those of the G115 base metal, and the development and the application of high-temperature resistant equipment are improved.
Description
Technical Field
The invention relates to the field of diffusion bonding of heat-resistant steel and nickel-based high-temperature alloy, in particular to a dissimilar metal diffusion bonding method of G115 heat-resistant steel and Inconel740 high-temperature alloy.
Background
The G115 heat-resistant steel (9Cr-2.8W-3CoCuVNbBN, the balance being Fe) is martensite heat-resistant steel independently developed in China and can be used for 630-plus 650 ℃ steam parameter ultra-supercritical thermal power generating units. The composition of the G115 steel is similar to that of the P93 alloy, the endurance strength of the G115 steel is 1.5 times that of the P92 steel at the temperature of 650 ℃, the high-temperature steam oxidation resistance and the weldability of the G115 steel are equivalent to those of the P92 steel, and the G115 steel is mainly applied to the manufacture of thick-wall parts such as large-caliber pipes, small-caliber superheaters, reheater pipes, headers and the like at the temperature of 650 ℃.
The Inconel740 alloy is a Ni-Cr-Co type precipitation strengthening nickel-based high-temperature alloy (main element 25Cr-20Co-2Nb, the balance being Ni) developed by American specialty Metals for an ultra-supercritical unit, and the purpose of the alloy development is to meet the requirement of a temperature range of over 700 ℃ on high-temperature resistant materials, and the Inconel740 alloy is successfully developed and verified at present. In addition, with the development of an ultra-supercritical power station and the improvement of the performance requirement of high-temperature resistant materials, in order to solve the problems that the Inconel740 alloy has unstable structure in the long-term aging process at 800 ℃, and the grain boundary of a heat affected zone is easy to generate liquefaction microcracks in the thick pipe welding process, in recent years, the Inconel740H which is the modified alloy and has better stability at 800 ℃ is developed through the fine adjustment of trace elements in the Inconel 740.
Because the G115 heat-resistant steel and the Inconel740 alloy (including the Inconel 740H) have good high-temperature mechanical property and high-temperature corrosion property, the G115 heat-resistant steel and the Inconel740 alloy are often used for manufacturing key high-temperature-resistant parts in the fields of ultra-supercritical power stations, nuclear power stations, aerospace and the like. However, the Inconel740 alloy has a Ni content of about 50 wt% and a Co content of about 20 wt%, and is much more expensive than the G115 heat-resistant steel. In order to reduce the manufacturing cost, different alloys are selected in different temperature sections, so that the design idea of a heat-resisting equipment system is formed, for example, GH115 is selected in a temperature section of 620-650 ℃, Inconel740 is selected in a temperature section of 700 ℃, and Inconel740H is selected in a temperature section of 800 ℃. When a plurality of heat-resistant alloys are in one heat-resistant system, the problem of connection of different heat-resistant alloys is inevitably generated.
However, nickel-based alloys (such as Inconel740 and Inconel 740H) have special physical properties, such as poor fluidity, high viscosity, high sensitivity to impurities, and the like, and are prone to generate defects such as pores and cracks when a fusion welding method (such as argon arc welding) is adopted, and the welding performance is poor. More seriously, when the Inconel740 nickel-based alloy and the G115 heat-resistant steel are directly fusion-welded, the defects are more easily caused due to the large difference of chemical compositions and thermal expansion coefficients.
The diffusion bonding is a process method which causes the surfaces to be bonded to generate plastic deformation and to be in close contact under the action of high temperature and pressure, and causes atoms to diffuse mutually to form a reliable joint after a certain time. The method is particularly suitable for preparing the joint with larger connecting area and higher requirements on dimensional accuracy and mechanical property. The preparation of the dissimilar metal joint is realized through diffusion bonding, and then the two ends of the dissimilar metal joint are respectively welded or connected with the metal of the same material, so that the process method is a process method which is hopeful to realize better connection of materials with different temperature sections and larger sizes. However, diffusion bonding of dissimilar metals has been a major difficulty due to large differences in material composition, melting point, thermal expansion coefficient, and the like.
Hojongjie (research on transient liquid phase diffusion bonding process and organization performance of CB2 heat-resistant steel [ D ]. Chongqing: Chongqing university, 2017.) respectively uses Ni-Cr-B and BNi-2 amorphous foils as intermediate layers, adopts a transient liquid phase diffusion bonding (TLP) technology, and simultaneously cooperates with heat treatment to carry out transient liquid phase diffusion bonding on CB2 heat-resistant steel. With BNi-2 amorphous as the middle layer, the non-isothermal solidification zone only appeared in the center of the joint at a connection parameter of 1050 ℃/60 s. The best tensile strength of the joint with the connection parameter of 1150 ℃/1800s is 934MPa, the elongation after fracture is 5.3 percent, and fracture occurs in the welded joint. After postweld heat treatment, the structural uniformity of a welded joint is obviously improved, tensile fracture occurs in a base metal, the tensile strength is 720MPa, and the elongation is improved to 18.3%. However, the prior art belongs to the same metal diffusion bonding method, and the bonding material CB2 (with the mark of 12Cr-9Mo-1Co1NiVNbNB) used has a larger composition difference compared with the bonding material G115 (with the mark of 9Cr-2.8W-3 cocutnbn) and the Inconel740 (Inconel 740H) high-temperature alloy (Ni-Cr-Co type precipitation strengthening high-temperature alloy), so that the bonding material CB2 cannot be applied to dissimilar metal diffusion bonding of the G115 heat-resistant steel and the Inconel740 (Inconel 740H) alloy.
Chenjie (research on heat-resistant steel transient liquid phase diffusion bonding interface structure and strengthening mechanism [ D ]. Saian: Sian university of Sian rational, 2008.) adopts electromagnetic induction heating and argon protection, FeNiCrSiB and BNi-2 amorphous foil alloy are used as intermediate layers, and T91, TP304H/12Cr1MoV and T91/12Cr2MoWVTiB transient liquid phase diffusion bonding experiments are carried out. The operation method in the prior art is that the workpiece is exposed in the atmosphere, diffusion connection is carried out under the protection of argon, and the induction coil is used for heating the joint, so that the shape and the size of the workpiece are limited, the large-size workpiece can not be connected, and the temperature is not accurate due to the accuracy of temperature control. Moreover, the paper only provides the diffusion bonding method of the heat-resistant steel, and does not relate to the diffusion bonding technology of the heat-resistant steel and the nickel-based superalloy.
Because the research on G115 and Inconel740 (Inconel 740H) in China is started late, no relevant research and report on the diffusion connection of the dissimilar metals of G115 and Inconel740 (Inconel 740H) exist, and the development and the application of high-temperature resistant equipment in China are severely limited.
Disclosure of Invention
In view of the above, the present invention provides a dissimilar metal diffusion bonding method for G115 heat-resistant steel and Inconel740 (Inconel 740H) high-temperature alloy. Through reasonable design of connection temperature, connection pressure, heat preservation time and the connection intermediate layer, the interdiffusion degree of elements between two parent metals is well controlled, and the defects of holes, cracks and the like at a connection interface are effectively avoided on the premise of ensuring better mechanical property. Meanwhile, the diffusion connection joint has good normal-temperature and high-temperature performances by optimizing the process and connecting the intermediate layer.
The invention realizes the instantaneous liquid phase diffusion connection of the G115 heat-resistant steel and Inconel740 or Inconel740H high-temperature alloy dissimilar metal by adopting a Ni-Cr-Si-Co (19Cr-10Si-3Co, the balance being Ni, mass percent) intermediate layer, and comprises the following specific steps:
step 1: machining, pre-grinding, polishing, cleaning and drying a to-be-connected surface of the G115 heat-resistant steel and the Inconel740 or the Inconel740H high-temperature alloy;
step 2: selecting a Ni-Cr-Si-Co (19Cr-10Si-3Co, the balance being Ni, mass percent) alloy foil with the thickness of 40-150 mu m as an intermediate layer; placing the intermediate layer between the G115 heat-resistant steel treated in the step (1) and the Inconel740 high-temperature alloy for assembling to form a prefabricated body;
and step 3: putting the prefabricated body assembled in the step 2 into a vacuum diffusion furnace, applying axial pressure of 0.2-0.5MPa, and pressing the prefabricated body tightly by an upper pressing head and a lower pressing head;
and 4, step 4: closing the furnace door, starting to vacuumize the vacuum diffusion furnace, and when the vacuum degree of the diffusion furnace reaches 10-2-10-3Heating is started when the pressure is Pa level;
and 5: heating to a connection heat preservation temperature;
step 6: when the furnace temperature reaches the connection heat preservation temperature, applying connection pressure on the prefabricated body in the diffusion furnace, and performing diffusion connection to form a joint;
and 7: after the connection is finished, cooling and stress relief annealing are carried out;
and 8: and performing performance heat treatment on the joint after connection to promote the diffusion of joint elements and improve the performance of the base metal.
In the step 1, the joint surface of the G115 heat-resistant steel and the Inconel740 or the Inconel740H high-temperature alloy is mechanically processed to the roughness Ra0.4-0.8, is pre-ground by 1000#, 2000# and 3000# sandpaper in sequence, and is polished by polishing cloth, so that the roughness of the joint surface of the two alloys is Ra0.2-0.4 grade, and the parallelism of the joint surface of the two alloys and a pressure head is less than 0.02 mm.
In the step 2, a Ni-Cr-Si-Co (19Cr-10Si-3Co, the balance being Ni, mass percent) alloy foil is selected as an intermediate layer, the Ni-Cr-Si-Co alloy foil is placed between the G115 heat-resistant steel and the Inconel740/Inconel 740H high-temperature alloy for assembly, and preferably, the Ni-Cr-Si-Co alloy foil is subjected to acid washing, rinsing with clear water, cleaning with alcohol or acetone, and drying.
For the Ni-Cr-Si-Co intermediate layer, the thickness is preferably 50 to 100 μm.
The acid wash is to soak the Ni-Cr-Si-Co interlayer with 10 wt% hydrochloric acid for 10 minutes.
In the step 5, in the process of from room temperature to 500 ℃, the heating rate is controlled to be 10-15 ℃/min, the furnace temperature reaches 500 ℃, and the temperature is kept for 20-60min, so that the furnace temperature is uniform; in the process of 500 ℃ to 900 ℃, the heating rate is controlled to be 5-10 ℃/min; keeping the temperature for 15-30min when the furnace temperature reaches 900 ℃ to further uniform the furnace temperature; in the process from 900 ℃ to the heat preservation temperature, the heating rate is controlled to be 3-8 ℃/min.
The heat preservation temperature is 1050-.
In the step 6, the connection pressure is 2-5MPa, preferably, the connection pressure is 3-4 MPa.
And in the step 6, the diffusion connection of the joint is completed after heat preservation is carried out for 1-3h, and preferably, the heat preservation is carried out for 2-3 h.
In step 7, the cooling includes the following steps:
the temperature reduction rate is 2-10 ℃/min from the connection heat preservation temperature to 1000 ℃; cooling at a rate of 8-20 deg.C/min from 1000 deg.C to 500 deg.C; preserving heat for 1-2h at 500 ℃, and performing stress relief annealing; furnace cooling from 500 deg.C to room temperature.
Preferably, the temperature reduction rate is 2-6 ℃/min from the stage of connecting the heat preservation temperature to 1000 ℃; at the stage from 1000 ℃ to 500 ℃, the cooling rate is 10-15 ℃/min; preserving heat for 1h at 500 ℃ for stress relief annealing; furnace cooling from 500 deg.C to room temperature.
In the step 8, the post-connection performance heat treatment is (1020-.
The invention has the following beneficial effects:
(1) according to the invention, a vacuum diffusion bonding method is adopted to realize the diffusion bonding of the G115 heat-resistant steel and the Inconel740 or the Inconel740H high-temperature alloy dissimilar metal. The normal-temperature and high-temperature mechanical properties of the G115 heat-resistant steel obtained by the method and the Inconel740 or Inconel740H high-temperature alloy dissimilar metal joint can exceed 90% of those of a G115 base material.
(2) The invention reduces the requirements of the diffusion bonding process on bonding temperature, bonding pressure and heat preservation time and improves the production efficiency by reasonably designing the type and thickness of the intermediate layer.
(3) According to the invention, 3 wt% of Co element is added into the Ni-Cr-Si system intermediate layer, so that the high temperature resistance of the intermediate layer is improved. In addition, the Ni-Cr-Si-Co intermediate layer designed by the invention does not contain B and other elements which are easy to generate brittle compounds, and the toughness of the joint is better.
(4) Aiming at the problems that the G115 heat-resistant steel and the Inconel740 or the Inconel740H high-temperature alloy have large component difference and easily generate diffusion holes, the process well controls the mutual diffusion degree of elements between two parent materials by reasonably designing the intermediate layer, the connection temperature, the connection pressure and the heat preservation time. On the premise of ensuring better mechanical property, defects such as holes and cracks at the connecting interface are effectively inhibited.
(5) According to the process, aiming at the difference of linear expansion coefficients of the G115 heat-resistant steel and the Inconel740 or the Inconel740H high-temperature alloy, the controlled cooling and stress relief annealing procedures are designed in the joint cooling process, so that the joint is reduced in the tendency of generating microcracks and cracking.
(6) The invention aims at the phenomenon that the strength of the G115 heat-resistant steel and the Inconel740 or the Inconel740H high-temperature alloy base materials is reduced under the action of high-temperature annealing at the connection temperature of 1050-1200 ℃ in the diffusion connection process. In order to solve the problem, a performance heat treatment process after connection is designed, and the strength of the base metal is improved. Meanwhile, in the process of heat treatment after connection, mutual diffusion of joint elements is further promoted, and the mechanical property of the joint is improved.
Detailed Description
Before further detailed description of the embodiments of the present invention, terms and expressions in the embodiments of the present invention and their corresponding uses, functions, and so on in the present invention are described, and the terms and expressions in the embodiments of the present invention are applicable to the following explanations.
The term "diffusion bonding" used in the present invention refers to a process of forming a reliable joint by plastically deforming and closely contacting the surfaces to be bonded under the action of high temperature and pressure and allowing inter-diffusion between atoms over a certain period of time. The method is particularly suitable for preparing the joint with larger connecting area and higher requirements on dimensional accuracy and mechanical property. The diffusion bonding process can be subdivided into various processes according to the equipment, the protection method and the presence or absence of an intermediate layer, wherein solid phase diffusion bonding and transient liquid phase diffusion bonding are more commonly used. As the name suggests, the solid phase diffusion bonding is a process method for forming metallurgical bonding by applying pressure to a connecting workpiece under the vacuum or gas protection condition and enabling the connecting interface to generate atomic diffusion under the condition that a workpiece base material is kept in a solid state. The instantaneous liquid phase diffusion bonding is to add a low-melting-point intermediate layer into a bonding interface of a parent metal, wherein the low-melting-point intermediate layer is melted but the parent metal is not melted in the bonding process; and (3) performing heat preservation homogenization treatment on the connecting workpiece for a long time to diffuse the liquid-phase intermediate layer into the base material, and finally obtaining the diffusion connection joint with the connection interface having more consistent components and tissues and the base material. Compared with solid-phase diffusion bonding, transient liquid-phase diffusion bonding has reduced requirements on the roughness of the bonding surface, diffusion bonding temperature and applied pressure.
The present invention will be further illustrated below with reference to specific examples in order that the invention may be more readily understood, and the advantages and features of the invention will become apparent from the description. However, these examples are only illustrative and do not limit the scope of the present invention, and the experimental methods described in the present invention are conventional methods unless otherwise specified.
Example 1: the specific operation steps for realizing the diffusion bonding of the G115 heat-resistant steel and the Inconel740 high-temperature alloy dissimilar metal by adopting the Ni-Cr-Si-Co intermediate layer are as follows:
step 1: machining the joint surface of the G115 heat-resistant steel and the Inconel740 high-temperature alloy to the roughness of Ra0.4-0.8, pre-grinding the joint surface by using 1000#, 2000# and 3000# sandpaper in sequence, and polishing the joint surface by using polishing cloth to ensure that the roughness of the joint surface of the two alloys is Ra0.2-0.4 grade and the parallelism of the joint surface of the two alloys and a pressure head is less than 0.02 mm.
Step 2: selecting a Ni-Cr-Si-Co (19Cr-10Si-3Co, the balance being Ni, mass percent) alloy foil with the thickness of 120 mu m as an intermediate layer, carrying out acid washing on the intermediate layer, cleaning the intermediate layer with clean water to remove acid liquor, cleaning with alcohol or acetone, and drying.
And step 3: assembling the G115 heat-resistant steel, the Inconel740 high-temperature alloy and the Ni-Cr-Si-Co intermediate layer which are treated in the steps 1 and 2 to form a prefabricated body, then putting the prefabricated body into a vacuum diffusion furnace, applying axial pressure of 0.2-0.5MPa, and pressing the prefabricated body by an upper pressing head and a lower pressing head.
And 4, step 4: closing the furnace door, starting to vacuumize the vacuum diffusion furnace, and when the vacuum degree of the diffusion furnace reaches 10-2-10-3And heating is started when the pressure is Pa.
And 5: in the process of from room temperature to 500 ℃, the heating rate is controlled to be 10-15 ℃/min; in the process of 500 ℃ to 900 ℃, the heating rate is controlled to be 5-10 ℃/min; keeping the temperature for 30min when the furnace temperature reaches 900 ℃ so as to further homogenize the furnace temperature; in the process from 900 ℃ to the heat preservation temperature, the heating rate is controlled to be 3-8 ℃/min.
Step 6: and when the furnace temperature reaches 1200 ℃ and the connection heat preservation temperature is reached, applying 5MPa connection pressure on the prefabricated body in the diffusion furnace, preserving heat for 3h to complete the diffusion connection of the joint, and forming the joint.
And 7: and after the connection is finished, cooling. Connecting the temperature from 1200 ℃ to 1000 ℃, and reducing the temperature at the rate of 5-10 ℃/min; cooling at a rate of 8-10 deg.C/min from 1000 deg.C to 500 deg.C; preserving heat for 1h at 500 ℃, and performing stress relief annealing; furnace cooling from 500 deg.C to room temperature. And taking out the joint after cooling.
And 8: and (3) placing the G115/Inconel 740 joint into a heat treatment furnace, and performing post-connection performance heat treatment according to a normalizing (air cooling) process of 1050 ℃ multiplied by 180min and 800 ℃ multiplied by 300 min. After cooling, the dissimilar metal joint of the G115 heat-resistant steel and the Inconel740 high-temperature alloy is obtained.
In conclusion, the G115 heat-resistant steel and the Inconel740 high-temperature alloy are connected under the conditions that the connection temperature is 1200 ℃, the connection pressure is applied at 5MPa, and the heat preservation time is 3 h. After connection, performing post-connection performance heat treatment according to a process of normalizing at 1050 ℃ for 180min and tempering (air cooling) at 800 ℃ for 300min to obtain the final dissimilar metal joint. The tensile strength of the G115 steel at normal temperature is 690MPa, and the tensile property at high temperature (650 ℃) is 130 MPa. In a test of the tensile strength of the G115/Inconel 740 dissimilar metal joint at normal temperature, the G115/Inconel 740 dissimilar metal joint is broken at one side of G115 steel, the tensile strength at break is 690MPa, and the joint strength exceeds the strength of the G115 steel. In a high-temperature (650 ℃) tensile strength test of a G115/Inconel 740 dissimilar metal joint, the joint is broken at one side close to a welding seam of G115 steel, the high-temperature breaking tensile strength is 123.6MPa, and the tensile strength reaches 95.1% of the high-temperature (650 ℃) tensile strength of a G115 parent metal.
Example 2: the specific operation steps for realizing the diffusion bonding of the G115 heat-resistant steel and the Inconel740H high-temperature alloy dissimilar metal by adopting the Ni-Cr-Si-Co intermediate layer are as follows:
step 1: the method comprises the steps of mechanically processing the joint surfaces of G115 heat-resistant steel and Inconel740H high-temperature alloy to the roughness of Ra0.4-0.8, pre-grinding with 1000#, 2000# and 3000# sandpaper in sequence, and polishing with polishing cloth to make the roughness of the joint surfaces of the two alloys Ra0.2-0.4 grade and ensure that the parallelism of the pressing surfaces of the joint surfaces of the two alloys contacting with a pressure head is less than 0.02 mm.
Step 2: selecting a Ni-Cr-Si-Co (19Cr-10Si-3Co, the balance being Ni, mass percent) alloy foil with the thickness of 50 mu m as an intermediate layer, carrying out acid washing on the intermediate layer, cleaning the intermediate layer with clean water to remove acid liquor, cleaning with alcohol or acetone, and drying. And (3) placing the treated Ni-Cr-Si-Co intermediate layer between the G115 heat-resistant steel and the Inconel740H high-temperature alloy in the step (1), and assembling to form a preform.
And step 3: and (3) putting the prefabricated body assembled in the step (2) into a vacuum diffusion furnace, applying axial pressure of 0.2-0.5MPa, and pressing the prefabricated body tightly by using an upper pressing head and a lower pressing head.
And 4, step 4: closing the furnace door, starting to vacuumize the vacuum diffusion furnace, and when the vacuum degree of the diffusion furnace reaches 10-2-10-3And heating is started when the pressure is Pa.
And 5: and heating and raising the temperature. Specifically, in the process of from room temperature to 500 ℃, the heating rate is controlled to be 10-15 ℃/min, the furnace temperature reaches 500 ℃, and the temperature is kept for 20-60min, so that the furnace temperature is uniform; in the process of 500 ℃ to 900 ℃, the heating rate is controlled to be 5-10 ℃/min; keeping the temperature for 30min when the furnace temperature reaches 900 ℃ to ensure that the furnace temperature is uniform; in the process of keeping the temperature from 900 ℃ to 1150 ℃, the heating rate is controlled to be 3-8 ℃/min.
Step 6: and when the furnace temperature reaches 1150 ℃ connection heat preservation temperature, applying 3MPa connection pressure on the prefabricated body in the diffusion furnace, and preserving heat for 2h to finish diffusion connection so as to form a joint.
And 7: and after the connection is finished, cooling and performing stress relief annealing. Connecting the stage from 1150 ℃ to 1000 ℃ with the heat preservation temperature, wherein the cooling rate is 2-5 ℃/min; at the stage from 1000 ℃ to 500 ℃, the cooling rate is 10-12 ℃/min; preserving heat for 1h at 500 ℃, and performing stress relief annealing; furnace cooling from 500 deg.C to room temperature.
And 8: and (3) placing the G115/Inconel 740H joint into a heat treatment furnace, and performing tempering (air cooling) treatment according to the normalizing temperature of 1020 ℃ multiplied by 120min and the tempering temperature of 790 ℃ multiplied by 210min to perform performance heat treatment after connection. After cooling, the dissimilar metal joint of the G115 heat-resistant steel and the Inconel740 high-temperature alloy is obtained.
The tensile strength of the G115 steel at normal temperature is 690MPa, and the tensile property at high temperature (650 ℃) is 130 MPa. In a normal-temperature tensile strength test, the G115/Inconel 740H dissimilar metal joint is broken at one side close to a G115 steel welding seam, the tensile strength of the joint reaches 626MPa, and the tensile strength reaches 90% of the strength (tensile strength 690MPa) of the G115 steel. In a high-temperature (650 ℃) tensile strength test of a G115/Inconel 740 dissimilar metal joint, the joint is broken at one side close to a welding seam of G115 steel, the high-temperature breaking tensile strength is 118MPa, and 90.7% of the high-temperature (650 ℃) tensile strength of a G115 parent metal is achieved.
Example 3: adopt Ni-Cr-Si-Co intermediate layer to realize the diffusion bonding of dissimilar metals of G115 heat-resistant steel and Inconel740 high-temperature alloy
The specific operation steps are as follows:
step 1: machining the joint surface of the G115 heat-resistant steel and the Inconel740 high-temperature alloy to the roughness of Ra0.4-0.8, pre-grinding the joint surface by using 1000#, 2000# and 3000# sandpaper in sequence, and polishing the joint surface by using polishing cloth to ensure that the roughness of the joint surface of the two alloys is Ra0.2-0.4 grade and the parallelism of the joint surface of the two alloys and a pressure head is less than 0.02 mm.
Step 2: selecting an alloy foil of Ni-Cr-Si-Co (19Cr-10Si-3Co, the balance being Ni, mass percent) with the thickness of 80 mu m as an intermediate layer, carrying out acid washing on the intermediate layer, cleaning the intermediate layer with clean water to remove acid liquor, cleaning with alcohol or acetone, and drying. And (3) placing the treated Ni-Cr-Si-Co intermediate layer between the G115 heat-resistant steel and the Inconel740 high-temperature alloy in the step (1), and assembling to form a prefabricated body.
And step 3: and (3) putting the prefabricated body assembled in the step (2) into a vacuum diffusion furnace, applying axial pressure of 0.2-0.5MPa, and pressing the prefabricated body tightly by using an upper pressing head and a lower pressing head.
And 4, step 4: closing the furnace door, starting to vacuumize the vacuum diffusion furnace, and when the vacuum degree of the diffusion furnace reaches 10-2-10-3And heating is started when the pressure is Pa.
And 5: and heating to the connection heat preservation temperature. Specifically, in the process of from room temperature to 500 ℃, the heating rate is controlled to be 10-15 ℃/min, the furnace temperature reaches 500 ℃, and the temperature is kept for 20-60min, so that the furnace temperature is uniform; in the process of 500 ℃ to 900 ℃, the heating rate is controlled to be 5-10 ℃/min; keeping the temperature for 30min when the furnace temperature reaches 900 ℃ to ensure that the furnace temperature is uniform; in the process of keeping the temperature from 900 ℃ to 1180 ℃, the heating rate is controlled to be 3-8 ℃/min.
Step 6: and when the furnace temperature reaches 1180 ℃ connection heat preservation temperature, applying 3MPa connection pressure on the prefabricated body in the diffusion furnace, and preserving heat for 3h to finish diffusion connection so as to form a joint.
And 7: and after the connection is finished, cooling and performing stress relief annealing. The temperature reduction rate is 2-5 ℃/min from the connection heat preservation temperature to 1000 ℃; at the stage from 1000 ℃ to 500 ℃, the cooling rate is 10-12 ℃/min; preserving heat for 1h at 500 ℃, and performing stress relief annealing; furnace cooling from 500 deg.C to room temperature. And taking out the joint after cooling.
And 8: and placing the G115/Inconel 740 joint into a heat treatment furnace, and performing tempering (air cooling) treatment according to the conditions of 1030 ℃ multiplied by 150min normalization and 795 ℃ multiplied by 240min to perform performance heat treatment after connection. After cooling, the dissimilar metal joint of the G115 heat-resistant steel and the Inconel740 high-temperature alloy is obtained. The tensile strength of the G115 steel at normal temperature is 690MPa, and the tensile property at high temperature (650 ℃) is 130 MPa. In the room temperature tensile strength test, the G115/Inconel 740 dissimilar metal joint is broken at one side of the G115 steel, the breaking tensile strength is 690MPa, and the room temperature tensile strength of the joint is proved to exceed the tensile strength of the G115 steel. In a high-temperature (650 ℃) tensile strength test of a G115/Inconel 740 dissimilar metal joint, the joint is broken at one side close to a welding seam of G115 steel, the high-temperature breaking tensile strength is 126MPa, and the high-temperature breaking tensile strength reaches 96.9% of the high-temperature (650 ℃) tensile strength of a G115 parent metal.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the present invention, and it will be understood by those skilled in the art that any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.
Claims (10)
1. A dissimilar metal diffusion bonding method of G115 heat-resistant steel and Inconel740 or Inconel740H high-temperature alloy is characterized by comprising the following steps:
step 1: machining, pre-grinding, polishing, cleaning and drying a to-be-connected surface of the G115 heat-resistant steel and the Inconel740 or the Inconel740H high-temperature alloy;
step 2: selecting a Ni-Cr-Si-Co alloy foil with the thickness of 40-150 mu m as an intermediate layer, wherein the mass percentage of the Ni-Cr-Si-Co alloy components is 19Cr-10Si-3Co, and the balance is Ni; placing the intermediate layer between the G115 heat-resistant steel treated in the step 1 and Inconel740 or Inconel740H high-temperature alloy for assembling to form a prefabricated body;
and step 3: putting the prefabricated body assembled in the step 2 into a vacuum diffusion furnace, applying axial pressure of 0.2-0.5MPa, and pressing the prefabricated body tightly by using an upper pressing head and a lower pressing head;
and 4, step 4: closing the furnace door, starting to vacuumize the vacuum diffusion furnace, and when the vacuum degree of the diffusion furnace reaches 10-2-10-3Heating is started when the pressure is Pa level;
and 5: heating to a connection heat preservation temperature;
step 6: when the furnace temperature reaches the connection heat preservation temperature, applying connection pressure on the prefabricated body in the diffusion furnace, and performing diffusion connection to form a joint;
and 7: after the connection is finished, cooling and stress relief annealing are carried out;
and 8: and performing performance heat treatment on the joint after connection, so that the performance of the base material is improved, and the diffusion of joint elements is promoted.
2. A diffusion bonding method of dissimilar metals according to claim 1, wherein in said step 1, the bonding surfaces of G115 heat-resistant steel and Inconel740 or Inconel740H high temperature alloy are machined to a roughness of ra0.4 to 0.8, pre-ground with 1000#, 2000# and 3000# sandpaper in this order, and then polished with a polishing cloth so that the roughness of the bonding surfaces of both alloys is ra0.2 to 0.4 grade, and the parallelism of the bonding surfaces of both alloys to the pressing surface in contact with the indenter is less than 0.02 mm.
3. The method for diffusion bonding dissimilar metals according to claim 2, wherein in the step 2, the Ni-Cr-Si-Co alloy foil is subjected to acid washing, rinsing with clean water, cleaning with alcohol or acetone, and drying.
4. The method for diffusion bonding dissimilar metals according to claim 1, wherein the thickness of the Ni-Cr-Si-Co intermediate layer is 50 to 100 μm.
5. The dissimilar metal diffusion bonding method according to claim 3, wherein the acid washing is soaking the Ni-Cr-Si-Co intermediate layer with 10 wt% hydrochloric acid for 10 minutes.
6. A dissimilar metal diffusion bonding method according to claim 1, wherein in the step 5, the temperature rise rate is controlled to 10 to 15 ℃/min during the temperature ranging from room temperature to 500 ℃, and the furnace temperature is kept at 500 ℃ for 20 to 60min, so that the furnace temperature is uniform; in the process of 500 ℃ to 900 ℃, the heating rate is controlled to be 5-10 ℃/min; keeping the temperature for 15-30min when the furnace temperature reaches 900 ℃ to further uniform the furnace temperature; in the process from 900 ℃ to the heat preservation temperature, the heating rate is controlled to be 3-8 ℃/min.
7. A dissimilar metal diffusion bonding method according to claim 1, wherein said heat-retaining temperature is 1050-.
8. A dissimilar metal diffusion bonding method according to claim 1, wherein in said step 6, said bonding pressure is 2 to 5MPa, preferably said bonding pressure is 3 to 4 MPa; and
and performing heat preservation for 1-3h to complete diffusion bonding to form the joint, and preferably, performing heat preservation for 2-3 h.
9. A dissimilar metal diffusion bonding method according to claim 1 or 8, wherein in the step 7, the temperature reduction includes the steps of:
the temperature reduction rate is 2-10 ℃/min from the connection heat preservation temperature to 1000 ℃; cooling at a rate of 8-20 deg.C/min from 1000 deg.C to 500 deg.C; preserving heat for 1-2h at 500 ℃, and performing stress relief annealing; cooling along with the furnace from 500 ℃ to room temperature, and taking out the joint after cooling;
preferably, the temperature reduction rate is 2-6 ℃/min from the stage of connecting the heat preservation temperature to 1000 ℃; at the stage from 1000 ℃ to 500 ℃, the cooling rate is 10-15 ℃/min; preserving heat for 1h at 500 ℃ for stress relief annealing; furnace cooling from 500 deg.C to room temperature.
10. A dissimilar metal diffusion bonding method according to claim 1 or 8, wherein in the step 8, the performance heat treatment after the bonding of the joint is 1020-.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110919299.0A CN113732479B (en) | 2021-08-11 | 2021-08-11 | Dissimilar metal diffusion bonding method for G115 heat-resistant steel and Inconel740 high-temperature alloy |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110919299.0A CN113732479B (en) | 2021-08-11 | 2021-08-11 | Dissimilar metal diffusion bonding method for G115 heat-resistant steel and Inconel740 high-temperature alloy |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113732479A true CN113732479A (en) | 2021-12-03 |
| CN113732479B CN113732479B (en) | 2022-11-18 |
Family
ID=78730776
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110919299.0A Active CN113732479B (en) | 2021-08-11 | 2021-08-11 | Dissimilar metal diffusion bonding method for G115 heat-resistant steel and Inconel740 high-temperature alloy |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113732479B (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114654070A (en) * | 2022-03-24 | 2022-06-24 | 河北工业大学 | Method for connecting dissimilar gamma' -phase reinforced high-temperature alloy |
| CN115198161A (en) * | 2022-07-25 | 2022-10-18 | 华能国际电力股份有限公司 | Header for 650 ℃ and above grade boiler unit and preparation method thereof |
| CN115537605A (en) * | 2022-09-30 | 2022-12-30 | 湖北易飞复合材料有限公司 | Transition metal composition for preventing interface element diffusion and titanium/steel assembly method |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH11197853A (en) * | 1998-01-16 | 1999-07-27 | Daido Steel Co Ltd | Joining method for martensitic stainless steel |
| CN101374631A (en) * | 2006-01-31 | 2009-02-25 | 新日本制铁株式会社 | Alloy for liquid-phase diffusion bonding |
| CN105598543A (en) * | 2016-03-25 | 2016-05-25 | 中国科学院金属研究所 | Silicon-boron-containing interlayer alloy for bonding nickel-based high-temperature alloy or stainless steel and application thereof |
| CN110666328A (en) * | 2019-11-01 | 2020-01-10 | 西安西工大超晶科技发展有限责任公司 | Diffusion welding method for cast high-temperature alloy and martensitic stainless steel |
| CN112853154A (en) * | 2021-01-04 | 2021-05-28 | 广东省科学院中乌焊接研究所 | Nickel-based intermediate layer alloy material, preparation method thereof, weldment, welding method and application |
-
2021
- 2021-08-11 CN CN202110919299.0A patent/CN113732479B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH11197853A (en) * | 1998-01-16 | 1999-07-27 | Daido Steel Co Ltd | Joining method for martensitic stainless steel |
| CN101374631A (en) * | 2006-01-31 | 2009-02-25 | 新日本制铁株式会社 | Alloy for liquid-phase diffusion bonding |
| CN105598543A (en) * | 2016-03-25 | 2016-05-25 | 中国科学院金属研究所 | Silicon-boron-containing interlayer alloy for bonding nickel-based high-temperature alloy or stainless steel and application thereof |
| CN110666328A (en) * | 2019-11-01 | 2020-01-10 | 西安西工大超晶科技发展有限责任公司 | Diffusion welding method for cast high-temperature alloy and martensitic stainless steel |
| CN112853154A (en) * | 2021-01-04 | 2021-05-28 | 广东省科学院中乌焊接研究所 | Nickel-based intermediate layer alloy material, preparation method thereof, weldment, welding method and application |
Non-Patent Citations (1)
| Title |
|---|
| 范玮等: "GH4169与DD6单晶合金TLP扩散焊接头组织及力学性能研究", 《焊接》 * |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114654070A (en) * | 2022-03-24 | 2022-06-24 | 河北工业大学 | Method for connecting dissimilar gamma' -phase reinforced high-temperature alloy |
| CN114654070B (en) * | 2022-03-24 | 2023-07-14 | 河北工业大学 | Connection method of dissimilar gamma' -phase reinforced superalloy |
| CN115198161A (en) * | 2022-07-25 | 2022-10-18 | 华能国际电力股份有限公司 | Header for 650 ℃ and above grade boiler unit and preparation method thereof |
| CN115198161B (en) * | 2022-07-25 | 2023-05-05 | 华能国际电力股份有限公司 | Header for boiler unit with temperature of 650 ℃ and above and preparation method thereof |
| CN115537605A (en) * | 2022-09-30 | 2022-12-30 | 湖北易飞复合材料有限公司 | Transition metal composition for preventing interface element diffusion and titanium/steel assembly method |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113732479B (en) | 2022-11-18 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN113732479B (en) | Dissimilar metal diffusion bonding method for G115 heat-resistant steel and Inconel740 high-temperature alloy | |
| CN106517828B (en) | It is a kind of that molybdenum group glass/kovar alloy laser soldering method is connected by addition Mo-Mn-Ni metal intermediate layer | |
| US8025983B2 (en) | Joining method between Fe-based steels and Ti/Ti-based alloys having joint strength higher than those of base metals by using interlayers and the joints produced using the method | |
| CN109014549B (en) | Diffusion welding connection method adopting Cu foil and Ti foil as composite intermediate layer | |
| CN107363359A (en) | A kind of method of compound high-entropy alloy solder ceramic soldering and metal | |
| CN101362253A (en) | TiNi shape memory alloy and stainless steel instant liquid-phase diffusion welding connection method | |
| CN113478062B (en) | Reaction diffusion connection method for titanium-zirconium-molybdenum alloy high-temperature-resistant joint | |
| CN110666328B (en) | Diffusion welding method for cast high-temperature alloy and martensitic stainless steel | |
| CN112643245B (en) | Cobalt-based alloy welding wire for welding high-temperature alloy and preparation method and application thereof | |
| CN111347147B (en) | Hot isostatic pressing connection method of tungsten and heat sink material | |
| CN113653573B (en) | Manufacturing method of inner wall blank of combustion chamber of aerospace engine | |
| CN102229019B (en) | Argon arc welding method suitable for TiAl-based alloy material and titanium alloy | |
| CN113020735B (en) | Preparation method of silicon nitride ceramic/stainless steel braze welding joint with corrosion resistance and stress relief | |
| CN107442922B (en) | Method for diffusion bonding of dissimilar materials by using amorphous interlayer | |
| CN110900037B (en) | Brazing filler metal and method for welding molybdenum-rhenium alloy and steel | |
| CN111826549A (en) | High-toughness titanium alloy and method for preparing bar by using same | |
| CN114799395B (en) | Vacuum brazing method for dissimilar nickel-based high-temperature alloy for improving strength stability of joint | |
| Bhanumurthy et al. | Transition joints between Zircaloy-2 and stainless steel by diffusion bonding | |
| CN114193014B (en) | Welding method of thick-wall aluminum-lithium alloy pipe fitting | |
| CN115679179B (en) | High-entropy alloy and application thereof in welding of titanium/steel composite plates | |
| CN114669956B (en) | Powder metallurgy repairing method for repairing defects of high-temperature alloy blade | |
| CN114193106B (en) | Processing method for compounding copper-based material on inner hole surface of tungsten-based material | |
| CN113478122B (en) | Ultrahigh-temperature brazing filler metal for connecting C/SiC composite material and niobium alloy, preparation process thereof and vacuum active brazing method | |
| CN114654070B (en) | Connection method of dissimilar gamma' -phase reinforced superalloy | |
| CN114807783B (en) | Iron-based shape memory alloy for stainless steel pipe joint at specific temperature and preparation method thereof |
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 | ||
| CP01 | Change in the name or title of a patent holder |
Address after: 100083 No. 18 clear road, Haidian District, Beijing Patentee after: China National Machinery Institute Group Beijing Electromechanical Research Institute Co.,Ltd. Address before: 100083 No. 18 clear road, Haidian District, Beijing Patentee before: BEIJING Research Institute OF MECHANICAL & ELECTRICAL TECHNOLOGY |
|
| CP01 | Change in the name or title of a patent holder |