Large-size copper-steel dense cavity component and high-sealing-reliability brazing manufacturing method thereof

Abstract

The invention discloses a large-size copper-steel dense cavity component and a high-sealing-reliability brazing manufacturing method of the large-size copper-steel dense cavity component. A cylindrical surface fitting and crossed brazing filler metal groove structure is designed on a component structure, a brazing filler metal presetting mode is that foil brazing filler metal is fixed on a stainless steel side wall surface, and a brazing wire is placed in an oxygen-free copper side wall brazing filler metal groove, so that the defect of large and small surrounding caused by large-area side wall surface brazing filler metal joint filling is effectively overcome, and the side wall sealing reliability is improved. Through the stepped solder groove blocking and sealing structure, the problem of sealing of the side walls of multiple cavities on the cylindrical surface with the same diameter is effectively solved, and the sealing efficiency is improved. The temperature of a workpiece in a furnace is monitored, uniform temperature rise of a large-size component is achieved in cooperation with a stepped uniform temperature control mode, the synchronous melting, seam filling, solidification and diffusion processes of brazing filler metal in different areas of the component are achieved, and the probability of generation of brazing seam defects is reduced. Therefore, the technical problem of high-reliability sealing of circumferential welds among large-size dense multiple cavities is solved, and high-sealing welding among copper / steel dense cavities is ensured.

Description

Technical Field

[0001] This invention relates to the technical field of copper-steel dissimilar metal welding, and in particular to a large-size copper-steel dense cavity component and its high-sealing-reliability brazing manufacturing method. Background Technology

[0002] As a process in advanced heat treatment, the large-size ( The (graded) copper-steel dense cavity component is a core cooling component in advanced heat treatment equipment. This heat treatment component heats up rapidly and reaches high temperatures, up to approximately 1200℃.

[0003] The structure mainly consists of stainless steel and oxygen-free copper. The stainless steel outer shell is located on the outside, serving to support the component; the oxygen-free copper inner core is located in the center, directly contacting the heating element, primarily for heat conduction and dissipation. The stainless steel and oxygen-free copper are connected as a whole using brazing technology. Before welding, cavities are milled inside the stainless steel and oxygen-free copper. After brazing, the inner cavities are sealed inside the outer shell, forming densely distributed reaction gas chambers and coolant chambers within the component structure. Furthermore, the area to be connected between adjacent cavities is narrow, and strict sealing and isolation between different cavities must be ensured during operation; any leakage would damage the entire working equipment. The difficulties lie in: ① the significant differences in composition, structure, and properties between oxygen-free copper and stainless steel increase the difficulty of connection; ② Ensuring a reliable and complete weld in the process of multi-layered circumferential welding is crucial, as leaks within the inner cavities cannot be repaired. This places high demands on the welding structure design and welding process. Therefore, there is an urgent need to explore welding specifications, process structures, and pre-placed brazing filler metal methods to overcome the welding challenge of achieving high-sealing welding between dense copper / steel cavities. Summary of the Invention

[0004] This invention provides a large-size copper-steel dense cavity component and its high-seal-reliability brazing manufacturing method, aiming to overcome the technical challenge of high-reliability sealing of circumferential welds between large-size dense multi-cavity channels.

[0005] In one aspect, a large-size copper-steel dense cavity component is provided, comprising a stainless steel outer ring and a copper core, wherein the copper core is placed inside the stainless steel outer ring.

[0006] The stainless steel outer ring is provided with a reaction gas port; the copper core is provided with a reaction gas ring groove corresponding to the reaction gas port of the stainless steel outer ring; after the stainless steel outer ring and the copper core are assembled, the reaction gas ring groove and the reaction gas port are connected, and a reaction gas chamber is formed between the stainless steel outer ring and the copper core at the position of the reaction gas ring groove.

[0007] The stainless steel outer ring is further provided with a water inlet and a water outlet; the copper core is formed with a water inlet groove with an angle less than 180 degrees on the side facing the water inlet of the stainless steel outer ring, and is formed with a water outlet groove with an angle less than 180 degrees on the side facing the water outlet of the stainless steel outer ring; after the stainless steel outer ring and the copper core are assembled, the water inlet groove and the water inlet are communicated, the water outlet groove and the water outlet are communicated, a water inlet cavity is formed between the copper core and the stainless steel outer ring at the position of the water inlet groove, and a water outlet cavity is formed between the copper core and the stainless steel outer ring at the position of the water outlet groove; the water inlet groove and the water outlet groove are not communicated, and the stainless steel outer ring and the copper core are connected by welding in the areas outside the water inlet cavity and the water outlet cavity to form a side wall sealing surface.

[0008] In combination with the first aspect, in some implementations of the first aspect, the side wall sealing surface between the water inlet cavity and the water outlet cavity is designed as a cylindrical surface fit, and is connected by foil brazing filler welding on the cylindrical surface fit; a cross solder groove structure is further arranged on the side wall sealing surface, and a brazing wire is placed in the cross solder groove for welding connection;

[0009] The cross solder groove structure includes multiple layers of solder grooves, each layer of solder grooves including a plurality of solder groove segments arranged at intervals; each solder groove segment in each layer of solder grooves includes a cross portion corresponding to a region in an adjacent layer where no solder groove segment is arranged.

[0010] In combination with the first aspect, in some implementations of the first aspect, the cylindrical fit gap between the stainless steel outer ring and the copper core is unilaterally controlled within 0.02 mm.

[0011] In combination with the first aspect, in some implementations of the first aspect, the component is provided with sealing grooves ① and ② between the reaction gas cavity and the outside world;

[0012] Between the reaction gas cavity and the water inlet cavity, the copper core is provided with a protruding first step, and the stainless steel outer ring is provided with a recessed first step groove corresponding to the first step; the horizontal fit surface and the vertical fit surface of the first step and the first step groove are respectively provided with sealing grooves ③ and ④;

[0013] Between the water inlet cavity and the outside world, the copper core is provided with a protruding second step, and the stainless steel outer ring is provided with a recessed second step groove corresponding to the second step; the horizontal fit surface and the vertical fit surface of the second step and the second step groove are respectively provided with sealing grooves ⑤ and ⑥;

[0014] A brazing wire is placed in the sealing grooves ① to ⑥.

[0015] In combination with the first aspect, in some implementations of the first aspect, the radii of the sealing grooves ② to ⑥ are different.

[0016] The second aspect provides a high-sealing-reliability brazing manufacturing method of the component as described in any one of the implementations of the first aspect, and adopts a stepped welding process curve to complete the welding connection of the stainless steel outer ring and the copper core.

[0017] In combination with the second aspect, in some implementations of the second aspect, the welding process curve includes a vacuum preparation phase, a temperature equalization preparation phase, and a welding phase, and satisfies:

[0018] The vacuum preparation phase is set to 350-450 DEG C for holding, and the holding time is 1-1.5 h, and the temperature rising rate from the vacuum preparation phase to the temperature equalization preparation phase is 10 DEG C / min;

[0019] The temperature equalization preparation phase is set to 700-800 DEG C for holding, and the holding time is 1-1.5 h, and the temperature rising rate from the temperature equalization preparation phase to the welding phase is 10 DEG C / min;

[0020] The welding phase is set to 1050-1150 DEG C for holding, and the holding time is 20-30 min, and after the welding is completed, the workpiece is cooled in the furnace.

[0021] In combination with the second aspect, in some implementations of the second aspect, in the temperature equalization preparation phase, a thermocouple is used to collect the temperature of the workpiece at different weld positions in the brazing furnace, the collected temperature information of the different weld regions is judged by a temperature control module, when the temperature difference is greater than a set temperature threshold AT, the holding is continued, and when the temperature difference is not more than the threshold AT, the program enters the next phase.

[0022] Compared with the prior art, the scheme provided by the present application has at least the following beneficial technical effects:

[0023] The present application is aimed at the connection of copper-steel heterogeneous metals in advanced heat treatment equipment and the sealing requirement of the components, and designs a welding structure of copper-steel dense cavity components, and proposes a brazing process, and obtains a high-sealing-reliability brazing manufacturing method of large-size copper-steel dense cavity components. The component structure is mainly composed of stainless steel and oxygen-free copper, and the two are connected into a whole by brazing technology. However, the oxygen-free copper and the stainless steel have large differences in composition, organization and performance, which increases the connection difficulty; in the process of brazing, the brazing filler metal is prone to be oxidized, and the brazing quality is difficult to control. In the process of multi-layered circumferential welding, ensuring reliable and complete welding in one go is crucial. Leaks within the cavities cannot be repaired with additional welding, placing high demands on the welding structure design and welding process. To address this, this invention proposes solutions for both the welding structure design and brazing process of copper-steel densely cavity components. Structurally, it features a cylindrical surface fitting + cross brazing groove structure. The brazing filler metal is pre-placed by fixing foil brazing filler metal to the stainless steel sidewall. Simultaneously, brazing wire is placed in the brazing groove on the oxygen-free copper sidewall, effectively solving the problem of large-area encirclement defects in brazing filler metal filling on large sidewall surfaces (60mm×40mm or even larger), improving the reliability of sidewall sealing. A stepped brazing groove barrier sealing structure is designed to effectively avoid the sealing problem of multi-cavity sidewalls on cylindrical surfaces with the same diameter, improving sealing efficiency. By monitoring the workpiece temperature inside the furnace and using a stepped temperature control method, uniform heating of large-sized components is achieved, enabling synchronous melting, filling, solidification, and diffusion of brazing filler metal in different areas of the component, reducing the probability of brazing defects. This invention overcomes the technical challenge of achieving high-reliability sealing of large-size, densely packed, multi-cavity inter-circular weld seams, ensuring high-sealing welding between densely packed copper / steel cavities. Attached Figure Description

[0024] Figure 1 This is an exploded view of a copper-steel dense cavity component.

[0025] Figure 2 This is a schematic diagram of a welded structure for a copper-steel dense cavity structure.

[0026] Figure 3 for Figure 2 Schematic diagram of section AA.

[0027] Figure 4 for Figure 2 Schematic diagram of the BB section.

[0028] Figure 5 This is a schematic diagram of a cylindrical surface with intersecting brazing grooves.

[0029] Figure 6 This is a schematic diagram of the welding process curve.

[0030] Figure 7 This is a schematic diagram of the temperature control inside the component furnace. Detailed Implementation

[0031] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0032] Figures 1 to 4 This invention illustrates a large-size copper-steel dense cavity component. For example... Figure 1 As shown, the large-size copper-steel dense cavity component includes a stainless steel outer ring and a copper core, with the copper core placed inside the stainless steel outer ring.

[0033] The stainless steel outer ring has a reaction gas port. The copper core has a reaction gas ring groove corresponding to the reaction gas port of the stainless steel outer ring. After the stainless steel outer ring and copper core are assembled, the reaction gas ring groove and the reaction gas port are connected. A reaction gas chamber is formed between the stainless steel outer ring and the copper core at the position of the reaction gas ring groove, such as... Figure 3 and Figure 4 As shown.

[0034] In addition, the stainless steel outer ring is equipped with an inlet and an outlet. A water inlet groove with a certain angle (less than 180°) is formed on the side of the copper core facing the stainless steel outer ring where the inlet is located, and a water outlet groove with a certain angle (less than 180°) is formed on the side of the copper core facing the stainless steel outer ring where the outlet is located. After the stainless steel outer ring and the copper core are assembled, the water inlet groove and the water outlet groove are connected, but the water inlet groove and the water outlet groove are not connected. A water inlet cavity is formed between the copper core and the stainless steel outer ring at the location of the water inlet groove, and a water outlet cavity is formed between the copper core and the stainless steel outer ring at the location of the water outlet groove, as shown below. Figure 2 and Figure 4 As shown. To prevent the inlet and outlet water chambers from communicating, the stainless steel outer ring and copper core are welded together in areas outside the inlet and outlet water chambers to form a sidewall sealing surface.

[0035] This invention includes two aspects: the welding structure design of copper-steel dense cavity components and the brazing process.

[0036] The welded structure design of copper-steel dense cavity components involves the design of the side wall sealing structure between the inlet and outlet cavities in the same layer, the arrangement of the brazing filler groove sealing structure between different layers of cavities, and the brazing filler prefabrication assembly method.

[0037] The sidewall sealing surfaces between the inlet and outlet water chambers are designed for cylindrical contact. The cylindrical contact structure between the stainless steel outer ring and the copper core facilitates assembly, and the clearance on each side is controlled within 0.02mm.

[0038] Furthermore, a cross brazing filler groove structure is also provided on the sidewall sealing surface, such as... Figure 5 As shown. The cross solder groove structure can be set on the copper core side. Specifically, the cross solder groove structure includes multiple layers of solder grooves, each layer comprising several solder groove segments spaced apart. The lengths of the solder groove segments in different layers can be different. It is important to note that the solder groove segments in adjacent layers are arranged crosswise. That is, each solder groove segment in each layer includes an intersecting portion, which corresponds to an area in the adjacent layer where no solder groove segment is provided.

[0039] exist Figure 5 In the embodiment shown, the interval between two adjacent solder groove segments in the same layer is 6 mm; the spacing between two adjacent solder groove layers is 8 mm; the multi-layer solder groove includes a first layer solder groove and a second layer solder groove, the length of the solder groove segment in the first layer solder groove is 16 mm, and the length of the solder groove segment in the second layer solder groove is 24 mm.

[0040] In the process of pre-placing the brazing filler metal on the side wall sealing surface, on the one hand, the foil brazing filler metal is fixed on the side wall surface of the stainless steel outer ring and the copper core, and on the other hand, the brazing wire is placed in the intersecting brazing groove. After the copper core is loaded, a sandwich structure of stainless steel / brazing filler metal / copper is formed. In the welding process, the brazing filler metal is melted, wet-spread and brazed into one body. In addition, the brazing wire in the brazing groove is melted and filled according to the capillary action, which serves the purpose of supplementing the brazing filler metal. The size surrounding defects of the brazing filler metal filling in the large area side wall surface (60mm*40mm) are effectively solved through the above two ways, and the side wall sealing reliability is improved.

[0041] A stepped brazing groove barrier sealing structure is designed for the sealing problem of different cavity dense arrangement structures. The stepped structure with a diameter of (D=400mm-550mm) is arranged on the circumferential sealing area between the stainless steel outer ring and the copper core, a plurality of gradient sealing interfaces between the layers are arranged, a multi-layer stepped sealing structure is formed, and the sealing efficiency is improved.

[0042] Specifically, between the reaction gas cavity and the outside, two sealing grooves are arranged, which are sealing grooves ① and ②. The sealing grooves ① and ② are used to avoid leakage between the outside and the reaction gas cavity. Between the reaction gas cavity and the water inlet cavity (or the water outlet cavity in the same layer), and between the water inlet cavity (or the water outlet cavity in the same layer) and the outside, the copper core is provided with a protruding step, and the stainless steel outer ring is correspondingly provided with a recessed step groove. The horizontal surface and the vertical surface corresponding to the two steps are respectively provided with sealing grooves. Among them, the two sealing grooves arranged between the reaction gas cavity and the water inlet cavity (or the water outlet cavity in the same layer) are sealing grooves ③ and ④, which are used to realize the isolation sealing between the reaction gas cavity and the water inlet cavity and the water outlet cavity. The two sealing grooves arranged between the water inlet cavity (or the water outlet cavity in the same layer) and the outside are sealing grooves ⑤ and ⑥, which are used to realize the isolation sealing between the water inlet cavity and the water outlet cavity and the outside. The brazing wire is placed in the sealing groove, and the brazing filler metal is melted, wet-spread, spread and solidified to achieve the sealing purpose.

[0043] The application also provides a manufacturing method of a large-size copper-steel dense cavity component. In the manufacturing method, through monitoring the temperature of the workpiece in the furnace and cooperating with the stepped uniform temperature control mode, the uniform heating of the large-size component is realized, the synchronous melting, filling, solidification and diffusion process of the brazing filler metal in different regions of the component are realized, and the probability of brazing seam defects is reduced.

[0044] As shown in FIG. 1, the copper core 2 is arranged in the stainless steel outer ring 1, and the copper core 2 is provided with a plurality of cavities 21. Figure 6As shown, specifically, the welding process curve is divided into three stages of temperature control. The vacuum preparation stage is set at 350–450℃ and held for 1–1.5 hours. This stage primarily monitors the vacuum atmosphere within the vacuum furnace, maintaining a high vacuum level to prevent subsequent heating from increasing the furnace vacuum and affecting welding quality. The heating rate from the vacuum preparation stage to the homogenization preparation stage is 10℃ / min. The homogenization preparation stage is set at 700–800℃ and held for 1–1.5 hours. This homogenization preparation stage is for achieving uniformity, such as… Figure 7 As shown, in this stage, thermocouples are used to collect the workpiece temperature at different weld locations within the brazing furnace. The temperature information from different weld areas is then analyzed using a temperature control module. If the temperature difference exceeds the set temperature threshold ΔT, the temperature is maintained at that temperature. If the temperature difference does not exceed the threshold ΔT, the program proceeds to the next stage. The heating rate from the homogenization preparation stage to the welding stage is 10℃ / min. The welding stage is set to maintain a temperature of 1050–1150℃ for 20–30 minutes. During the welding stage, the workpiece temperature is monitored until it reaches the required welding temperature T. 焊 The holding time (t) ensures that the solder fully melts, wets, fills the gaps, and undergoes a diffusion reaction, achieving reliable structural welding. The weld is then cooled in the furnace after completion.

[0045] Example 1:

[0046] Figures 1 to 4 A copper-steel dense cavity component is shown. The sealing surface between the inlet and outlet chambers of the same layer is configured as a sidewall sealing structure, and is designed... Figure 5 The diagram shows a cross-shaped brazing filler groove structure. The cylindrical mating structure between the stainless steel outer ring and the copper core facilitates assembly, with the mating gap controlled to 0.02mm on each side. A cross-shaped brazing filler groove structure is set on the oxygen-free copper sidewall. The brazing filler is pre-placed by fixing foil brazing filler to the stainless steel sidewall and placing brazing wire in the brazing filler groove on the oxygen-free copper sidewall. After pre-placing the brazing filler, the stainless steel and oxygen-free copper are assembled, forming a steel / brazing filler / copper sandwich structure. During welding, the brazing filler melts, wets, spreads, and brazes into a single unit. Furthermore, the brazing wire in the filler groove melts and fills the gaps through capillary action, supplementing the brazing filler.

[0047] Designed Figure 4 The design shown is in The stepped structure (D=400mm~550mm) forms a multi-layer stepped sealing structure, effectively avoiding the sealing problem of multiple cavity sidewalls on a cylindrical surface with the same diameter, and improving sealing efficiency. Six circumferential sealing grooves are designed for the sealing method: ①, ②, ③, ④, ⑤, and ⑥ sealing grooves.

[0048] Welding process curve as follows Figure 6 The temperature control method is divided into three stages, and the schematic diagram of the furnace temperature control is as follows:Figure 7 The vacuum degree preparation stage, which sets a low temperature T1 holding stage, mainly monitors the vacuum atmosphere in the vacuum furnace by reducing the furnace vacuum degree to a high vacuum atmosphere to avoid subsequent heating of the furnace vacuum degree increase affecting the welding quality; the high temperature holding stage is a uniformity preparation stage, in which the thermocouple is used to collect the temperature of the workpiece at different weld positions in the brazing furnace, and the collected temperature information of different weld areas is used to judge the temperature control module, when the temperature difference is greater than the set temperature threshold AT, continue to hold, when the temperature difference does not exceed the threshold AT, the program enters the next stage; the third stage is the welding stage, which monitors the workpiece temperature to reach the welding requirement temperature T 焊 And the holding time t.

[0049] This embodiment effectively solves the size of the large-size side wall (60mm*40mm or even larger scale area) filler appears size surrounding defects, improve the reliability of the side wall sealing. The brazing filler metal groove is placed in the brazing wire, and the brazing filler metal is melted, wetted, spreaded and solidified to achieve the sealing purpose. Ensure that the solder is fully melted, wetted, filled and diffused, realize reliable welding of structure,

[0050] Although the present application is disclosed in the preferred embodiments as above, it is not intended to limit the present application, any person skilled in the art can make possible changes and modifications without departing from the spirit and scope of the present application, therefore, the protection scope of the present application should be limited by the scope defined by the claims of the present application.

Claims

1. A large-sized copper steel dense cavity member, characterized by, The copper core is arranged in the stainless steel outer ring; The stainless steel outer ring is provided with a reaction gas port; the copper core is provided with a reaction gas ring groove corresponding to the reaction gas port of the stainless steel outer ring; the reaction gas ring groove and the reaction gas port are communicated after the stainless steel outer ring and the copper core are assembled, and a reaction gas cavity is formed between the stainless steel outer ring and the copper core at the position of the reaction gas ring groove; The stainless steel outer ring is further provided with a water inlet and a water outlet; one side of the copper core facing the water inlet of the stainless steel outer ring is formed with a water inlet groove with an angle less than 180°, and one side of the copper core facing the water outlet of the stainless steel outer ring is formed with a water outlet groove with an angle less than 180°; the water inlet groove and the water outlet groove are not communicated, and the stainless steel outer ring and the copper core are connected by welding in the area outside the water inlet cavity and the water outlet cavity to form a side wall sealing surface.

2. The structure of claim 1, wherein The side wall sealing surface between the water inlet cavity and the water outlet cavity is designed as a cylindrical surface fitting, and is welded and connected by foil solder in the cylindrical surface fitting surface; a cross solder groove structure is further arranged on the side wall sealing surface, and a soldering wire is placed in the cross solder groove for welding connection; The cross solder groove structure includes multiple layers of solder grooves, and each layer of solder groove includes a plurality of solder groove segments arranged at intervals; each solder groove segment in each layer of solder groove includes a cross portion corresponding to the area in the adjacent layer where no solder groove segment is arranged.

3. The structure of claim 1, wherein The cylindrical fitting gap between the stainless steel outer ring and the copper core is unilaterally controlled within 0.02mm.

4. The structure of claim 1, wherein The component is provided with sealing grooves ① and ② between the reaction gas cavity and the outside world; Between the reaction gas cavity and the water inlet cavity, the copper core is provided with a protruding first step, and the stainless steel outer ring is provided with a recessed first step groove corresponding to the first step; the horizontal and vertical fitting surfaces of the first step and the first step groove are respectively provided with sealing grooves ③ and ④; Between the water inlet cavity and the outside world, the copper core is provided with a protruding second step, and the stainless steel outer ring is provided with a recessed second step groove corresponding to the second step; the horizontal and vertical fitting surfaces of the second step and the second step groove are respectively provided with sealing grooves ⑤ and ⑥; A soldering wire is placed in the sealing grooves ①-⑥.

5. The structure of claim 4, wherein The radii of the sealing grooves ②-⑥ are different.

6. A brazing method for manufacturing a member with high sealing reliability as claimed in any one of claims 1 to 5, characterized by, A stepped welding process curve is adopted to complete the welding connection of the stainless steel outer ring and the copper core.

7. The structure of claim 6, wherein The welding process curve includes a vacuum preparation stage, a uniform temperature preparation stage and a welding stage, which satisfies: The vacuum preparation stage is set to 350-450℃ for 1-1.5h, and the temperature rising rate from the vacuum preparation stage to the uniform temperature preparation stage is 10℃ / min; The uniform temperature preparation stage is set to 700-800℃ for 1-1.5h; the temperature rising rate from the uniform temperature preparation stage to the welding stage is 10℃ / min; The welding stage is set to 1050-1150℃ for 20-30min; and the furnace cooling is performed after the welding is completed.

8. The structure of claim 7, wherein In the uniform temperature preparation stage, the thermocouples are used to collect the workpiece temperatures at different weld positions in the brazing furnace, the collected temperature information of the different weld areas is judged by the temperature control module, when the temperature range is greater than the set temperature threshold AT, the temperature is continued, and when the temperature range is not more than the threshold AT, the program enters the next stage.

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