Welding material for preparing copper-stainless steel gradient structure and cmt preparation method

Abstract

The application discloses a welding material for preparing a copper-stainless steel gradient structure, which comprises a welding material for preparing a near-stainless steel transition layer and a welding material for preparing a near-copper transition layer; the material is specially used for solving the forming difference and the steel-side penetration cracking problem caused by the thermal physical property mismatch during the connection of the copper-steel dissimilar structures. The application further discloses a CMT preparation method for the copper-stainless steel gradient structure by using the welding material for preparing the copper-stainless steel gradient structure.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of metal materials, and particularly relates to a welding material for preparing a copper-stainless steel gradient structure, and further relates to a CMT preparation method for preparing a copper-stainless steel gradient structure by using the welding material. BACKGROUND

[0002] Copper alloy has excellent electrical conductivity and thermal conductivity, and austenitic stainless steel has the characteristics of low cost and high strength. The copper-steel composite joint formed by combining the two has the advantages of both. However, the connection of copper and steel belongs to the connection of dissimilar materials. Although no brittle phase is generated when the two are welded and connected, the difference in thermal physical properties is huge, so the welding forming is poor, and penetration cracks are easily formed on the steel side. For the welding connection of dissimilar materials, preparing a transition layer is an effective solution. SUMMARY

[0003] The purpose of the present application is to provide a welding material for preparing a copper-stainless steel gradient structure, which is specially used to solve the problems of poor forming and penetration cracking on the steel side caused by the mismatch of thermal physical properties during the connection of copper-steel dissimilar structures.

[0004] Another purpose of the present application is to provide a CMT preparation method for preparing a copper-stainless steel gradient structure by using the welding material for preparing a copper-stainless steel gradient structure.

[0005] The first technical solution adopted by the present application is a welding material for preparing a copper-stainless steel gradient structure, which includes a near-stainless steel side transition layer preparation welding material and a near-copper side transition layer preparation welding material.

[0006] The near-stainless steel side transition layer preparation welding material includes powder and a welding skin, and the powder includes the following components in mass percentage: Ni powder 40.0-50.0%, Cr powder 20.0-30.0%, Mo powder 5.0-8.0%, Nb powder 2.0-4.0%, Ag powder 2.0-4.0%, CeO2 powder 0.5-1.0%, and the rest is Fe powder.

[0007] The near-copper side transition layer preparation welding material includes powder and a welding skin, and the powder includes the following components in mass percentage: Ni powder 20.0-30.0%, Ag powder 10.0-20.0%, Mo powder 10.0-20.0%, Y2O3 powder 0.5-1.0%, and the rest is Cu powder.

[0008] The present application is characterized in that:

[0009] The particle size of the flux used in the welding material for preparing the near-stainless steel side transition layer and the welding material for preparing the near-copper side transition layer is 100-200 mesh.

[0010] The welding sheath of the welding material for preparing the near-stainless steel side transition layer is a 430 steel strip with a thickness of 0.4 mm and a width of 7 mm; and the filling rate of the flux of the welding material for preparing the near-stainless steel side transition layer is controlled to be 20-23 wt%.

[0011] The welding sheath of the welding material for preparing the near-copper side transition layer is a red copper strip with a thickness of 0.4 mm and a width of 7 mm; and the filling rate of the flux of the welding material for preparing the near-copper side transition layer is controlled to be 30-32 wt%.

[0012] The preparation method of the welding material for preparing the near-stainless steel side transition layer includes the following specific steps:

[0013] Step 1: Ni powder 40.0-50.0%, Cr powder 20.0-30.0%, Mo powder 5.0-8.0%, Nb powder 2.0-4.0%, Ag powder 2.0-4.0%, CeO2 powder 0.5-1.0%, and the rest Fe powder are weighed according to the mass percentage;

[0014] Step 2: The flux weighed in step 1 is heated in a vacuum heating furnace, the heating temperature is 200-250°C, and the holding time is 1-3 h to remove the crystal water in the flux; the dried flux is placed in a powder mixer for sufficient mixing, and the mixing time is 2-6 h;

[0015] Step 3: The alcohol is used to remove the grease on the surface of the steel strip, and the flux prepared in step 2 is wrapped in the 430 steel strip through the flux-cored wire drawing equipment, and the first drawing die hole diameter is 2.6 mm; and the filling rate of the flux of the welding material for preparing the near-stainless steel side transition layer is controlled to be 20-23 wt%;

[0016] Step 4: After the first process drawing is completed, the die hole diameter is gradually reduced, and finally the flux-cored wire with a diameter of 1.0-1.2 mm is obtained;

[0017] Step 5: After the flux-cored wire drawing is completed, the wire is wound on the welding wire disc through the winding machine, and finally sealed in the flux-cored wire vacuum packaging bag for use;

[0018] The preparation method of the welding material for preparing the near-copper side transition layer includes the following specific steps:

[0019] Step 1: Ni powder 20.0-30.0%, Ag powder 10.0-20.0%, Mo powder 10.0-20.0%, Y2O3 powder 0.5-1.0%, and the rest Cu powder are weighed according to the mass percentage;

[0020] Step 2: the medicine powder weighed in step 1 is heated in a vacuum heating furnace, the heating temperature is 200-220 DEG C, and the holding time is 2-3 hours, so that the crystal water in the medicine powder is removed; the dried medicine powder is placed in a powder mixer for sufficient mixing, and the mixing time is 2-3 hours;

[0021] Step 3: alcohol is used to remove grease on the surface of the red copper strip, the medicine powder prepared in step 2 is wrapped in the red copper strip through a core wire drawing equipment, and the first drawing die hole diameter is 2.6 mm; the filling rate of the medicine powder of the welding material for the near copper side transition layer is controlled to be 30-32 wt%;

[0022] Step 4: after the first process drawing is completed, the die hole diameter is sequentially reduced, and finally the diameter of the flux-cored wire is 1.0-1.2 mm;

[0023] Step 5: after the flux-cored wire drawing is completed, the wire is wound on the welding wire disc through a winding machine, and finally sealed in a vacuum packaging bag for use.

[0024] The second technical scheme adopted in the application is that the CMT preparation method of the copper-stainless steel gradient structure is prepared by using the above-mentioned copper-stainless steel gradient structure preparation welding material, and the specific steps are as follows:

[0025] (1) first, the near steel side transition layer preparation welding material is selected to prepare the near steel side transition layer on the surface of the stainless steel base body, the CMT welding current is 180-200 A, the cladding layer thickness is 3-5 mm, and the interlayer temperature is below 100 DEG C, so as to ensure the size accuracy of the cladding layer;

[0026] (2) then, the near copper side transition layer preparation welding material is selected to prepare the near copper side transition layer on the near steel side transition layer, the CMT welding current is 200-220 A, the cladding layer thickness is 3-5 mm, and the interlayer temperature is below 100 DEG C, so as to ensure the size accuracy of the cladding layer;

[0027] (3) finally, the S201 welding wire is used to perform arc cladding preparation on the near copper side transition layer, the CMT welding current is 220-250 A, the cladding layer thickness is 10-15 mm, and the continuous cladding is not controlled.

[0028] The beneficial effects of the application are:

[0029] (1) The present application is directed to the problem of poor welding forming and steel side cracking caused by large thermal physical property difference in the process of copper-stainless steel dissimilar material welding connection, and proposes to prepare copper-steel gradient structure by using double-layer transition layer, so as to obtain high-quality copper-steel heterogeneous structure. The welding material of the present application is specially used to solve the problems of poor forming and steel side penetration cracking caused by the mismatch of thermal physical properties in the connection of copper-steel heterogeneous structure.

[0030] (2) The near-steel side transition layer prepared on the 410 stainless steel substrate also uses a stainless steel system, and the alloy system is Fe-Cr-Ni, which has small difference in alloying elements with 410 stainless steel, and can ensure high-quality metallurgical bonding with the 410 stainless steel substrate.

[0031] (3) The near-copper side transition layer of the present application uses copper-based welding material and adds Ni, Ag, Mo and other elements. These elements are also added in the near-steel side transition layer, so that the addition of these elements in the near-copper side transition layer ensures the excellent bonding strength of the side transition layer and also ensures the metallurgical bonding performance with the stainless steel side transition layer.

[0032] (4) The present application uses CMT arc to prepare the near-steel layer transition layer on the 410 stainless steel substrate, and prepares the near-copper layer transition layer on the near-steel layer transition layer, and finally forms the copper-steel gradient structure.

[0033] (5) In order to solve the problem of poor connection quality caused by large thermal physical property difference in the direct welding connection of copper and steel, the present application proposes a strategy of preparing a gradient transition layer. The gradient transition layer can realize the continuous transition of alloying elements from copper to steel side, thereby reducing the stress concentration of the joint and improving the strength and toughness of the joint. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 It is a schematic diagram of the copper-stainless steel gradient structure prepared by CMT arc in the present application;

[0035] Figure 2 It is the microstructure of the near-steel layer transition layer in the copper-stainless steel gradient structure prepared by using Example 2;

[0036] Figure 3 It is the microstructure of the near-copper layer transition layer in the copper-stainless steel gradient structure prepared by using Example 2;

[0037] Figure 4 It is the tensile fracture scanning electron microscope observation morphology of the copper-stainless steel gradient structure prepared by Example 2. DETAILED DESCRIPTION

[0038] The present application will be described in detail below in combination with the drawings and specific embodiments.

[0039] The application provides welding materials for preparing copper-stainless steel gradient structures, including welding materials for preparing near-stainless steel transition layers and welding materials for preparing near-copper transition layers.

[0040] The welding material for preparing the near-stainless steel transition layer comprises powder and a welding skin, wherein the powder comprises the following components in percentage by mass: Ni powder 40.0-50.0%, Cr powder 20.0-30.0%, Mo powder 5.0-8.0%, Nb powder 2.0-4.0%, Ag powder 2.0-4.0%, CeO2 powder 0.5-1.0%, and the rest is Fe powder, and the sum of the percentage by mass of the above components is 100%.

[0041] The welding material for preparing the near-copper transition layer comprises powder and a welding skin, wherein the powder comprises the following components in percentage by mass: Ni powder 20.0-30.0%, Ag powder 10.0-20.0%, Mo powder 10.0-20.0%, Y2O3 powder 0.5-1.0%, and the rest is Cu powder, and the sum of the percentage by mass of the above components is 100%.

[0042] The purity of each raw material component powder is greater than or equal to 99.9%.

[0043] The particle size of the powder used in the welding material for preparing the near-stainless steel transition layer and the welding material for preparing the near-copper transition layer is 100-200 mesh.

[0044] The welding skin of the welding material for preparing the near-stainless steel transition layer is a 430 steel strip with a thickness of 0.4 mm and a width of 7 mm, and the powder filling rate of the welding material for preparing the near-stainless steel transition layer is controlled to be 20-23 wt%.

[0045] The welding skin of the welding material for preparing the near-copper transition layer is a red copper strip with a thickness of 0.4 mm and a width of 7 mm, and the powder filling rate of the welding material for preparing the near-copper transition layer is controlled to be 30-32 wt%.

[0046] The functions of the main components of the above welding materials are as follows:

[0047] (1) The main element of the welding material for preparing the near-stainless steel transition layer is Fe (from the 430 welding skin and the powder): since the first principle of the welding material for preparing the near-stainless steel transition layer is to realize good metallurgical bonding with the stainless steel base body, in the application, 410 stainless steel is used as the base body, an Fe-Cr-Ni alloy system is designed, and the main element in the welding material is also Fe, so that the bonding strength with the stainless steel base body can be ensured.

[0048] (2) The main added element of the welding material for preparing the near stainless steel side transition layer is Cr (from the 430 welding skin and the flux powder): The addition of Cr is also for good metallurgical bonding between the transition layer and the 410 stainless steel base, and the content of Cr in the welding material for the near stainless steel side transition layer is higher than that of the 410 stainless steel base, so that the transition of the Fe element in the transition layer to the near copper layer can be reduced. According to the Cr-Fe binary phase diagram, the solid solubility of Cr in Fe is large, and the weldability of the two is good; according to the Cr-Cu binary phase diagram, although the solid solubility of Cr in Cu is low, the two will not generate a brittle phase.

[0049] (3) The main added element of the welding material for preparing the near stainless steel side transition layer is Ni (from the flux powder): According to the Fe-Ni and Cu-Ni binary phase diagrams, Ni is an element that can form metallurgical bonding with Fe and Cu at the same time. Therefore, the addition of Ni in the near stainless steel side transition layer can improve the bonding strength with the stainless steel base and ensure high-quality bonding with the copper side. In addition, Ni and Cr can mutually solid-solve, so the addition of Ni can make up for the low solid solubility of Cr and Cu.

[0050] (4) The welding material for preparing the near stainless steel side transition layer adds Mo and Nb elements (from the flux powder): Mo and Nb elements are solid solution strengthening elements for the Fe base. These two elements can be solid-solved in the Fe base, causing lattice distortion, thereby improving the strength of the near stainless steel side transition layer.

[0051] (5) The welding material for preparing the near stainless steel side transition layer adds Ag element (from the flux powder): The main purpose of adding Ag element here is to reduce the melting point of the welding material. According to the Ag-Fe and Ag-Cu binary phase diagrams, neither of them will generate a brittle phase, so Ag is an element that can effectively reduce the melting point of the welding material.

[0052] (6) The welding material for preparing the near stainless steel side transition layer adds CeO2 powder (from the flux powder): Since the near steel side transition layer is designed to be a stainless steel system, and it is a ferritic stainless steel system, the ferritic stainless steel often has coarse grains and weak grain boundaries. Therefore, adding CeO2 element in the welding material for the near steel side transition layer can effectively purify the ferritic grain boundaries and reduce the grain size.

[0053] (7) The main element of the welding material for preparing the near copper side transition layer is Cu (from the red copper tape welding skin and the flux powder): The copper side transition layer is directly connected with copper, so the design of taking Cu as the main element can ensure excellent metallurgical bonding performance.

[0054] (8) The main additive element of the welding material for preparing the near-copper side transition layer is Ni (from the powder): this element is added in both the near-steel side transition layer and the near-copper side transition layer, on the one hand to achieve excellent bonding between the two transition layers, and on the other hand to achieve the connection between the near-copper side transition layer and the copper matrix, because Cu-Ni is an infinite solid solution alloy system. The solid solution of Ni in Cu can also improve the strength of the copper side transition layer.

[0055] (9) The welding material for preparing the near-copper side transition layer adds Ag element (from the powder): according to the Cu-Ag binary phase diagram, the solid solution between the two is large, and the weldability is excellent. Ag element is also added in the near-steel side transition layer, and when added in the near-copper side transition layer, it can achieve good metallurgical bonding between the two transition layers. In addition, the addition of Ag can also reduce the melting point of the copper-based welding material, thereby reducing the penetration cracks on the steel side.

[0056] (10) The welding material for preparing the near-copper side transition layer adds Mo element (from the powder): Mo element is added in both the near-steel side transition layer and the near-copper side transition layer, which can improve the connection strength of the two transition layers. In addition, the solid solubility of Mo in the Cu matrix is relatively larger than that of Cr, so the addition of Mo can further improve the strength of the copper side transition layer.

[0057] (11) The welding material for preparing the near-copper side transition layer adds Y2O3 powder (from the powder): the near-copper side transition layer is mainly composed of Cu element, with relatively large grain size, similar to the near-steel side transition layer, so rare earth oxide is added to refine the grain size of the near-copper side transition layer. Here, Y2O3 oxide is added, which is different from CeO2 oxide in the near-steel side transition layer, both of which belong to rare earth oxides. Different rare earth oxides are selected for the purpose of synergistic grain size refinement and grain boundary purification. The combined effect of multiple rare earth oxides is often more obvious than that of a single rare earth oxide.

[0058] The preparation method of the welding material for preparing the near-stainless steel side transition layer is as follows:

[0059] Step 1: weigh the Ni powder 40.0-50.0%, Cr powder 20.0-30.0%, Mo powder 5.0-8.0%, Nb powder 2.0-4.0%, Ag powder 2.0-4.0%, CeO2 powder 0.5-1.0%, and the rest is Fe powder, according to the mass percentage; the sum of the mass percentages of the above components is 100%;

[0060] Step 2: The drug powder weighed in step 1 is placed in a vacuum heating furnace for heating, the heating temperature is 200-250 DEG C, and the holding time is 1-3 h, to remove the crystal water in the drug powder; the dried drug powder is placed in a powder mixer for thorough mixing, and the mixing time is 2-6 h;

[0061] Step 3: Alcohol is used to remove the grease on the surface of the steel strip, and the drug powder prepared in step 2 is wrapped in the 430 steel strip through the flux-cored wire drawing equipment, and the first drawing die hole diameter is 2.6 mm; the filling rate of the drug powder of the welding material for preparing the near-stainless steel transition layer is controlled at 20-23 wt%;

[0062] Step 4: After the first process drawing is completed, the die hole diameter is sequentially reduced, and finally the flux-cored wire with a diameter of 1.0-1.2 mm is obtained;

[0063] Step 5: After the flux-cored wire drawing is completed, the wire is wound on the welding wire disc through the winding machine, and finally sealed in the flux-cored wire vacuum packaging bag for use;

[0064] The preparation method of the welding material for preparing the near-copper transition layer is as follows:

[0065] Step 1: The Ni powder 20.0-30.0%, Ag powder 10.0-20.0%, Mo powder 10.0-20.0%, Y2O3 powder 0.5-1.0%, and the rest Cu powder are weighed according to the mass percentage, and the sum of the mass percentages of the above components is 100%;

[0066] Step 2: The drug powder weighed in step 1 is placed in a vacuum heating furnace for heating, the heating temperature is 200-220 DEG C, and the holding time is 2-3 h, to remove the crystal water in the drug powder; the dried drug powder is placed in a powder mixer for thorough mixing, and the mixing time is 2-3 h;

[0067] Step 3: Alcohol is used to remove the grease on the surface of the red copper strip, and the drug powder prepared in step 2 is wrapped in the red copper strip through the flux-cored wire drawing equipment, and the first drawing die hole diameter is 2.6 mm; the filling rate of the drug powder of the welding material for preparing the near-copper transition layer is controlled at 30-32 wt%;

[0068] Step 4: After the first process drawing is completed, the die hole diameter is sequentially reduced, and finally the flux-cored wire with a diameter of 1.0-1.2 mm is obtained;

[0069] Step 5: After the flux-cored wire drawing is completed, the wire is wound on the welding wire disc through the winding machine, and finally sealed in the flux-cored wire vacuum packaging bag for use.

[0070] The application further discloses a CMT preparation method of the copper-stainless steel gradient structure by using the copper-stainless steel gradient structure and the welding material, and the welding material for preparing the copper-stainless steel gradient structure includes welding material for preparing the near-stainless steel transition layer and welding material for preparing the near-copper transition layer. Figure 1 The specific steps are as follows:

[0071] (1) First, the welding material for preparing the near-stainless steel transition layer is selected to prepare the near-stainless steel transition layer on the surface of the 410 stainless steel base body, the CMT welding current is 180A-200A, the thickness of the surfacing layer is 3mm-5mm, and the temperature between layers is below 100 DEG C, so as to ensure the size accuracy of the surfacing layer.

[0072] (2) Then, the welding material for preparing the near-copper transition layer is selected to prepare the near-copper transition layer on the near-stainless steel transition layer, the CMT welding current is 200A-220A, the thickness of the surfacing layer is 3mm-5mm, and the temperature between layers is below 100 DEG C, so as to ensure the size accuracy of the surfacing layer.

[0073] (3) Finally, the S201 welding wire is used to perform arc surfacing preparation on the near-copper transition layer, the CMT welding current is 220A-250A, the thickness of the surfacing layer is 10mm-15mm, and the surfacing is continuous without controlling the layer temperature.

[0074] Example 1

[0075] The specific steps of the preparation method of the welding material for the near-stainless steel transition layer are as follows:

[0076] Step 1: Ni powder 40.0%, Cr powder 20.0%, Mo powder 5.0%, Nb powder 2.0%, Ag powder 2.0%, CeO2 powder 0.5%, and the rest is Fe powder are weighed according to the mass percentage, and the sum of the mass percentages of the above components is 100%.

[0077] Step 2: The powder prepared in step 1 is heated in a vacuum heating furnace, the heating temperature is 200 DEG C, and the holding time is 1h, so as to remove the crystal water in the powder; the dried powder is placed in a powder mixer for sufficient mixing, and the mixing time is 2h.

[0078] Step 3: Alcohol is used to remove grease on the surface of the steel strip, the powder prepared in step 2 is wrapped in the 430 steel strip through a flux-cored wire drawing equipment, and the hole diameter of the first drawing die is 2.6mm.

[0079] Step 4: After the first drawing process is completed, the die hole diameter is sequentially reduced, and finally the flux-cored wire with a diameter of 1.2mm is obtained.

[0080] Step 5: After the core wire drawing is completed, the core wire is wound on the welding wire disc by the winding machine, and finally sealed in the core wire vacuum packaging bag for use.

[0081] The preparation method of the near copper side welding material is as follows:

[0082] Step 1: The powders are weighed according to the mass percentage, that is, 20.0% of Ni powder, 10.0% of Ag powder, 10.0% of Mo powder, 0.5% of Y2O3 powder, and the rest is Cu powder. The sum of the mass percentages of the above components is 100%.

[0083] Step 2: The powders weighed in step 1 are heated in a vacuum heating furnace, the heating temperature is 200℃, and the holding time is 2h to remove the crystal water in the powders; the dried powders are placed in a powder mixer for thorough mixing, and the mixing time is 2h;

[0084] Step 3: The alcohol is used to remove the grease on the surface of the red copper strip, and the powders prepared in step 2 are wrapped in the red copper strip by the core wire drawing equipment, and the first drawing die hole diameter is 2.6mm;

[0085] Step 4: After the first process drawing is completed, the die hole diameter is gradually reduced, and finally the core wire with a diameter of 1.2mm is obtained.

[0086] Step 5: After the core wire drawing is completed, the core wire is wound on the welding wire disc by the winding machine, and finally sealed in the core wire vacuum packaging bag for use.

[0087] The particle size of the powders used for the near stainless steel side transition layer preparation welding material and the near copper side transition layer preparation welding material is 100 mesh.

[0088] The sheath of the near stainless steel side transition layer preparation welding material is a 430 steel strip with a thickness of 0.4mm and a width of 7mm; the powder filling rate of the near stainless steel side transition layer preparation welding material is controlled at 20wt%.

[0089] The sheath of the near copper side transition layer preparation welding material is a red copper strip with a thickness of 0.4mm and a width of 7mm; the powder filling rate of the near copper side transition layer preparation welding material is controlled at 30wt%.

[0090] The transition layer welding material prepared in Example 1 is used to prepare a copper-stainless steel gradient structure, and the specific steps of the CMT preparation method are as follows (as shown in Figure 1 ).

[0091] (1) First, the near stainless steel side welding material of the present application is selected to prepare a near steel side transition layer on the surface of a 410 stainless steel substrate, the CMT welding current is 180~200A, the cladding layer thickness is 3mm, and the interlayer temperature is 90℃ to ensure the dimensional accuracy of the cladding layer;

[0092] (2) Then, the near-copper side welding material of the application is selected to prepare the near-copper side transition layer on the above-mentioned near-steel side transition layer, the CMT welding current is 200-220 A, the thickness of the surfacing layer is 3 mm, and the interlayer temperature is 90℃ to ensure the dimensional accuracy of the surfacing layer;

[0093] (3) Finally, the S201 welding wire is used to perform arc surfacing on the above-mentioned near-copper side transition layer to prepare the copper matrix, the CMT welding current is 220-250 A, the thickness of the surfacing layer is 10 mm, and continuous surfacing is performed without controlling the layer temperature.

[0094] Through testing, the results of the copper-stainless steel gradient structure are as follows:

[0095] (1) The near-stainless steel side transition layer is mainly composed of ferrite structure, and no cracks or inclusion defects are observed;

[0096] (2) The near-copper side transition layer is mainly composed of Cu solid solution, and no cracks or inclusion defects are observed;

[0097] (3) The tensile strength of the copper-stainless steel gradient structure is 351 MPa, and the fracture position is in the copper side matrix.

[0098] Example 2

[0099] The preparation method of the near-stainless steel side transition layer welding material is as follows:

[0100] Step 1: The Ni powder, Cr powder, Mo powder, Nb powder, Ag powder, CeO2 powder, and the rest of the Fe powder are weighed according to the mass percentage of 50.0%, 30.0%, 8.0%, 4.0%, 4.0%, 1.0%, and 100%, respectively.

[0101] Step 2: The powder prepared in step 1 is placed in a vacuum heating furnace and heated to a temperature of 250℃ for 3h to remove the crystal water in the powder; the dried powder is placed in a powder mixer for thorough mixing for 6h;

[0102] Step 3: The alcohol is used to remove the grease on the surface of the steel strip, and the powder prepared in step 2 is wrapped in the 430 steel strip through the core wire drawing equipment, and the first drawing die hole diameter is 2.6mm;

[0103] Step 4: After the first process drawing is completed, the die hole diameter is gradually reduced, and finally a diameter of 1.0mm of the core wire is obtained.

[0104] Step 5: After the core wire drawing is completed, it is wound on the welding wire disc through the winding machine, and finally sealed in the core wire vacuum packaging bag for use.

[0105] The preparation method of the near-copper side welding material is as follows:

[0106] Step 1: The powders of Ni, Ag, Mo, Y2O3 and Cu are weighed according to the mass percentage of 30.0%, 20.0%, 20.0%, 1.0% and the rest respectively, and the sum of the mass percentages of the above components is 100%.

[0107] Step 2: The powders weighed in step 1 are heated in a vacuum heating furnace, the heating temperature is 220℃, and the holding time is 3h to remove the crystal water in the powders; the dried powders are placed in a powder mixer for thorough mixing, and the mixing time is 3h;

[0108] Step 3: The alcohol is used to remove the grease on the surface of the red copper tape, and the powders prepared in step 2 are wrapped in the red copper tape through the core wire drawing equipment, and the first drawing die hole diameter is 2.6mm;

[0109] Step 4: After the first process drawing is completed, the die hole diameter is gradually reduced, and finally the diameter of the flux-cored wire is 1.0mm.

[0110] Step 5: After the flux-cored wire drawing is completed, it is wound on the wire spool through the winding machine, and finally sealed in the vacuum packaging bag of the flux-cored wire for use.

[0111] The particle size of the powders used for the near stainless steel side transition layer preparation welding material and the near copper side transition layer preparation welding material is 200 mesh.

[0112] The sheath of the near stainless steel side transition layer preparation welding material is a 430 steel tape with a thickness of 0.4mm and a width of 7mm; the powder filling rate of the near stainless steel side transition layer preparation welding material is controlled at 23wt%.

[0113] The sheath of the near copper side transition layer preparation welding material is a red copper tape with a thickness of 0.4mm and a width of 7mm; the powder filling rate of the near copper side transition layer preparation welding material is controlled at 32wt%.

[0114] The transition layer welding material prepared by example 2 is used to prepare the copper-stainless steel gradient structure, and the specific steps of the CMT preparation method are as follows (as shown in Figure 1 ).

[0115] (1) First, the near stainless steel side welding material of the application is selected to prepare the near steel side transition layer on the surface of the 410 stainless steel base body, the CMT welding current is 180~200A, the cladding layer thickness is 5mm, and the interlayer temperature is at 80℃ to ensure the dimensional accuracy of the cladding layer;

[0116] (2) Next, the copper-side welding material of the present invention is selected to prepare the copper-side transition layer on the steel-side transition layer. The CMT welding current is 200-220A, the thickness of the cladding layer is 5mm, and the interlayer temperature is 80°C to ensure the dimensional accuracy of the cladding layer.

[0117] (3) Finally, S201 welding wire was used to prepare the copper substrate by arc surfacing on the above-mentioned transition layer near the copper side. The CMT welding current was 220~250A, the thickness of the surfacing layer was 15mm, and the surfacing was continuous without controlling the layer temperature.

[0118] After testing, the results of the copper-stainless steel gradient structure are as follows:

[0119] (1) The transition layer near the stainless steel side is mainly composed of ferrite, with no cracks or inclusion defects;

[0120] (2) The transition layer near the copper side is mainly composed of Cu solid solution, with no cracks or inclusion defects;

[0121] (3) The tensile strength of the copper-stainless steel gradient structure is 359 MPa, and the fracture location is on the copper side matrix.

[0122] Figure 2 The microstructure of the transition layer near the steel layer in the copper-stainless steel gradient structure prepared in Example 2. Figure 2 It can be seen that the transition layer near the steel side is mainly composed of single-phase ferrite with clear grain boundaries.

[0123] Figure 3 The microstructure of the transition layer near the copper layer in the copper-stainless steel gradient structure prepared in Example 2. Figure 3 It can be seen from the figure that the transition layer near the copper side is mainly composed of single-phase Cu structure with clear grain boundaries.

[0124] Figure 4 The tensile fracture morphology of the copper-stainless steel gradient structure prepared in Example 2 was observed by scanning electron microscopy. Figure 4 It can be seen from the figure that the fracture is mainly dimple morphology, and the toughness is good.

[0125] Example 3

[0126] The preparation method of the welding material for the transition layer near the stainless steel side includes the following specific steps:

[0127] Step 1: Weigh 45.0% Ni powder, 25.0% Cr powder, 7.0% Mo powder, 3.0% Nb powder, 3.0% Ag powder, 0.7% CeO2 powder, and the rest Fe powder according to mass percentage. The sum of the mass percentages of the above components is 100%.

[0128] Step 2: The powder weighed in step 1 is placed in a vacuum heating furnace and heated at 230°C for 2 hours to remove the crystal water in the powder; the dried powder is placed in a powder mixer and fully mixed for 4 hours;

[0129] Step 3: Use alcohol to remove grease from the surface of the steel strip, and wrap the powder prepared in step 2 in the 430 steel strip through the flux-cored wire drawing equipment. The aperture of the first drawing die is 2.6mm;

[0130] Step 4: After the first drawing process is completed, the die aperture is reduced in sequence to finally obtain a flux-cored welding wire with a diameter of 1.2 mm.

[0131] Step 5: After the flux-cored wire is drawn, it is wound onto a wire reel by a wire winding machine and finally sealed in a flux-cored wire vacuum packaging bag for use.

[0132] The preparation method of the copper-side welding material includes the following specific steps:

[0133] Step 1: Weigh 25.0% Ni powder, 15.0% Ag powder, 15.0% Mo powder, 0.7% Y2O3 powder, and the rest Cu powder according to mass percentage. The sum of the mass percentages of the above components is 100%.

[0134] Step 2: The powder weighed in step 1 is placed in a vacuum heating furnace and heated at a temperature of 210°C for 2.5 hours to remove the crystal water in the powder; the dried powder is placed in a powder mixer and fully mixed for 2.5 hours;

[0135] Step 3: Use alcohol to remove grease from the surface of the copper strip, and wrap the powder prepared in step 2 inside the copper strip through a flux-cored wire drawing device. The aperture of the first drawing die is 2.6 mm.

[0136] Step 4: After the first drawing process is completed, the die aperture is reduced in sequence to finally obtain a flux-cored welding wire with a diameter of 1.2 mm.

[0137] Step 5: After the flux-cored wire is drawn, it is wound onto a wire reel by a wire winding machine and finally sealed in a flux-cored wire vacuum packaging bag for use.

[0138] The particle size of the powder used in the welding materials for preparing the transition layer near the stainless steel side and the welding materials for preparing the transition layer near the copper side are both 100 meshes.

[0139] The weld skin of the welding material used for preparing the transition layer near the stainless steel side is 430 steel strip with a thickness of 0.4 mm and a width of 7 mm; the powder filling rate of the welding material used for preparing the transition layer near the stainless steel side is controlled at 21wt%.

[0140] The welding sheath of the welding material for preparing the near-copper side transition layer is a red copper strip with a thickness of 0.4 mm and a width of 7 mm; and the powder filling rate of the welding material for preparing the near-copper side transition layer is controlled at 31 wt%.

[0141] The transition layer welding material prepared in Example 3 is used to prepare a copper-stainless steel gradient structure, and the specific steps of the CMT preparation method are as follows (as shown in Figure 1

[0142] (1) First, the near-stainless steel side welding material of the present application is selected to prepare a near-steel side transition layer on the surface of a 410 stainless steel base body, the CMT welding current is 180-200 A, the cladding layer thickness is 4 mm, and the interlayer temperature is 70°C to ensure the dimensional accuracy of the cladding layer;

[0143] (2) Then, the near-copper side welding material of the present application is selected to prepare a near-copper side transition layer on the above-mentioned near-steel side transition layer, the CMT welding current is 200-220 A, the cladding layer thickness is 4 mm, and the interlayer temperature is 70°C to ensure the dimensional accuracy of the cladding layer;

[0144] (3) Finally, S201 welding wire is used to perform arc cladding on the above-mentioned near-copper side transition layer to prepare a copper base body, the CMT welding current is 220-250 A, the cladding layer thickness is 13 mm, and continuous cladding is performed without controlling the layer temperature.

[0145] After testing, the results of the copper-steel gradient structure are as follows:

[0146] (1) The near-stainless steel side transition layer is mainly composed of ferrite structure, and no cracks or inclusion defects are observed;

[0147] (2) The near-copper side transition layer is mainly composed of Cu solid solution, and no cracks or inclusion defects are observed;

[0148] (3) The tensile strength of the copper-steel gradient structure is 351 MPa, and the fracture position is in the copper side base body.

[0149] Example 4

[0150] The preparation method of the welding material for preparing the near-stainless steel side transition layer includes the following specific steps:

[0151] Step 1: The Ni powder, Cr powder, Mo powder, Nb powder, Ag powder, CeO2 powder, and the rest of the Fe powder are weighed according to the mass percentage of 43.0%, 23.0%, 6.0%, 3.5%, 3.5%, 0.9%, and the sum of the mass percentages of the above components is 100%.

[0152] ​Step 2: The drug powder weighed in step 1 is placed in a vacuum heating furnace for heating, the heating temperature is 220℃, and the holding time is 1.3h to remove the crystal water in the drug powder; the dried drug powder is placed in a powder mixer for thorough mixing, and the mixing time is 2.6h;

[0153] Step 3: Alcohol is used to remove the grease on the surface of the steel strip, and the drug powder prepared in step 2 is wrapped in the 430 steel strip through the flux-cored wire drawing equipment, and the first drawing die hole diameter is 2.6mm;

[0154] Step 4: After the first process drawing is completed, the die hole diameter is gradually reduced, and finally the flux-cored wire with a diameter of 1.0mm is obtained.

[0155] Step 5: After the flux-cored wire drawing is completed, it is wound on the welding wire disc through the winding machine, and finally sealed in the flux-cored wire vacuum packaging bag for use.

[0156] The preparation method of the near-copper side welding material is as follows:

[0157] Step 1: Ni powder 22.0%, Ag powder 12.0%, Mo powder 12.0%, Y2O3 powder 0.6%, and the rest is Cu powder are weighed according to the mass percentage, and the sum of the mass percentages of the above components is 100%.

[0158] Step 2: The drug powder weighed in step 1 is placed in a vacuum heating furnace for heating, the heating temperature is 215℃, and the holding time is 2.3h to remove the crystal water in the drug powder; the dried drug powder is placed in a powder mixer for thorough mixing, and the mixing time is 2.3h;

[0159] Step 3: Alcohol is used to remove the grease on the surface of the red copper strip, and the drug powder prepared in step 2 is wrapped in the red copper strip through the flux-cored wire drawing equipment, and the first drawing die hole diameter is 2.6mm;

[0160] Step 4: After the first process drawing is completed, the die hole diameter is gradually reduced, and finally the flux-cored wire with a diameter of 1.0mm is obtained.

[0161] Step 5: After the flux-cored wire drawing is completed, it is wound on the welding wire disc through the winding machine, and finally sealed in the flux-cored wire vacuum packaging bag for use.

[0162] The particle size of the drug powder used for the near-stainless steel side transition layer preparation welding material and the near-copper side transition layer preparation welding material is 200 mesh.

[0163] The welding sheath of the near-stainless steel side transition layer preparation welding material is a 430 steel strip with a thickness of 0.4mm and a width of 7mm; the drug powder filling rate of the near-stainless steel side transition layer preparation welding material is controlled at 23wt%.

[0164] The welding sheath of the welding material for preparing the near-copper side transition layer is a red copper strip with a thickness of 0.4 mm and a width of 7 mm; and the powder filling rate of the welding material for preparing the near-copper side transition layer is controlled at 32 wt%.

[0165] The transition layer welding material prepared in Example 4 is used to prepare a copper-stainless steel gradient structure, and the specific steps of the CMT preparation method are as follows (as shown in Figure 1

[0166] (1) First, the near-stainless steel side welding material of the present application is selected to prepare a near-steel side transition layer on the surface of a 410 stainless steel base body, the CMT welding current is 180-200 A, the cladding layer thickness is 3.5 mm, and the interlayer temperature is 60°C to ensure the dimensional accuracy of the cladding layer;

[0167] (2) Then, the near-copper side welding material of the present application is selected to prepare a near-copper side transition layer on the above-mentioned near-steel side transition layer, the CMT welding current is 200-220 A, the cladding layer thickness is 3.5 mm, and the interlayer temperature is below 60°C to ensure the dimensional accuracy of the cladding layer;

[0168] (3) Finally, S201 welding wire is used to perform arc cladding on the above-mentioned near-copper side transition layer to prepare a copper base body, the CMT welding current is 220-250 A, the cladding layer thickness is 12.5 mm, and continuous cladding is performed without controlling the layer temperature.

[0169] After testing, the results of the copper-stainless steel gradient structure are as follows:

[0170] (1) The near-stainless steel side transition layer is mainly composed of ferrite structure, and no cracks or inclusion defects are observed;

[0171] (2) The near-copper side transition layer is mainly composed of Cu solid solution, and no cracks or inclusion defects are observed;

[0172] (3) The tensile strength of the copper-stainless steel gradient structure is 347 MPa, and the fracture position is in the copper side base body.

[0173] Example 5

[0174] The preparation method of the welding material for preparing the near-stainless steel side transition layer includes the following specific steps:

[0175] Step 1: The Ni powder, Cr powder, Mo powder, Nb powder, Ag powder, CeO2 powder, and the rest of the Fe powder are weighed according to the mass percentage of 49.0%, 29.0%, 5.50%, 2.7%, 2.8%, 0.55%, and the sum of the mass percentages of the above components is 100%.

[0176] ​Step 2: The drug powder weighed in step 1 is placed in a vacuum heating furnace for heating, the heating temperature is 218℃, and the holding time is 2.8h to remove the crystal water in the drug powder; the dried drug powder is placed in a powder mixer for thorough mixing, and the mixing time is 5.7h;

[0177] Step 3: Alcohol is used to remove the grease on the surface of the steel strip, and the drug powder prepared in step 2 is wrapped in the 430 steel strip through the flux-cored wire drawing equipment, and the first drawing die hole diameter is 2.6mm;

[0178] Step 4: After the first process of drawing is completed, the die hole diameter is gradually reduced, and finally the flux-cored wire with a diameter of 1.2mm is obtained.

[0179] Step 5: After the drawing of the flux-cored wire is completed, it is wound on the welding wire disc through the winding machine, and finally sealed in the flux-cored wire vacuum packaging bag for use.

[0180] The preparation method of the near-copper side welding material is as follows:

[0181] Step 1: Ni powder 28.0%, Ag powder 19.0%, Mo powder 17.0%, Y2O3 powder 0.58%, and the rest is Cu powder are weighed according to the mass percentage, and the sum of the mass percentages of the above components is 100%.

[0182] Step 2: The drug powder weighed in step 1 is placed in a vacuum heating furnace for heating, the heating temperature is 219℃, and the holding time is 2.7h to remove the crystal water in the drug powder; the dried drug powder is placed in a powder mixer for thorough mixing, and the mixing time is 2.8h;

[0183] Step 3: Alcohol is used to remove the grease on the surface of the red copper strip, and the drug powder prepared in step 2 is wrapped in the red copper strip through the flux-cored wire drawing equipment, and the first drawing die hole diameter is 2.6mm;

[0184] Step 4: After the first process of drawing is completed, the die hole diameter is gradually reduced, and finally the flux-cored wire with a diameter of 1.2mm is obtained.

[0185] Step 5: After the drawing of the flux-cored wire is completed, it is wound on the welding wire disc through the winding machine, and finally sealed in the flux-cored wire vacuum packaging bag for use.

[0186] The particle size of the drug powder used for the near-stainless steel side transition layer preparation welding material and the near-copper side transition layer preparation welding material is 100 mesh.

[0187] The welding sheath of the near-stainless steel side transition layer preparation welding material is a 430 steel strip with a thickness of 0.4mm and a width of 7mm; the drug powder filling rate of the near-stainless steel side transition layer preparation welding material is controlled at 22wt%.

[0188] The welding sheath of the welding material for preparing the near-copper side transition layer is a red copper strip with a thickness of 0.4 mm and a width of 7 mm; and the powder filling rate of the welding material for preparing the near-copper side transition layer is controlled at 32 wt%.

[0189] The transition layer welding material prepared in Example 5 is used to prepare a copper-stainless steel gradient structure, and the specific steps of the CMT preparation method are as follows (as shown in Figure 1

[0190] (1) First, the near-stainless steel side welding material of the present application is selected to prepare a near-steel side transition layer on the surface of a 410 stainless steel base body, the CMT welding current is 180-200 A, the cladding layer thickness is 3.2 mm, and the interlayer temperature is 50°C to ensure the dimensional accuracy of the cladding layer;

[0191] (2) Then, the near-copper side welding material of the present application is selected to prepare a near-copper side transition layer on the above near-steel side transition layer, the CMT welding current is 200-220 A, the cladding layer thickness is 3.9 mm, and the interlayer temperature is 50°C to ensure the dimensional accuracy of the cladding layer;

[0192] (3) Finally, S201 welding wire is used to perform arc cladding on the above near-copper side transition layer to prepare a copper base body, the CMT welding current is 220-250 A, the cladding layer thickness is 11 mm, and continuous cladding is performed without controlling the layer temperature.

[0193] After testing, the results of the copper-stainless steel gradient structure are as follows:

[0194] (1) The near-stainless steel side transition layer is mainly composed of ferrite structure, and no cracks or inclusion defects are observed;

[0195] (2) The near-copper side transition layer is mainly composed of Cu solid solution, and no cracks or inclusion defects are observed;

[0196] (3) The tensile strength of the copper-stainless steel gradient structure is 350 MPa, and the fracture position is in the copper side base body.​

Claims

1. Welding material for preparing copper-stainless steel gradient structure, characterized in that: Including welding materials for preparing transition layer near stainless steel side and welding materials for preparing transition layer near copper side; Among them, the welding materials for preparing the transition layer near the stainless steel side include flux powder and weld skin, wherein the flux powder includes the following components by mass percentage: the following components by mass percentage: Ni powder 40.0~50.0%, Cr powder 20.0~30.0%, Mo powder 5.0~8.0%, Nb powder 2.0~4.0%, Ag powder 2.0~4.0%, CeO2 powder 0.5~1.0%, and the rest is Fe powder, and the sum of the mass percentages of the above components is 100%; Welding materials for preparing transition layers near the copper side, including flux powder and solder coating, wherein the flux powder comprises the following components by mass percentage: Ni powder 20.0-30.0%, Ag powder 10.0-20.0%, Mo powder 10.0-20.0%, Y2O3 powder 0.5-1.0%, and the remainder is Cu powder, and the sum of the mass percentages of the above components is 100%; The weld material for the transition layer near the stainless steel side is 430 steel strip with a thickness of 0.4 mm and a width of 7 mm. The powder filling rate of the welding material for the transition layer near the stainless steel side is controlled at 20 wt% to 23 wt%. The solder coating of the welding material for preparing the transition layer near the copper side is a copper strip with a thickness of 0.4 mm and a width of 7 mm; the powder filling rate of the welding material for preparing the transition layer near the copper side is controlled at 30wt%~32wt%.

2. The welding material for preparing a copper-stainless steel gradient structure according to claim 1, characterized in that: The particle size of the powder used in the welding materials for preparing the transition layer near the stainless steel side and the welding materials for preparing the transition layer near the copper side are both 100 mesh to 200 mesh.

3. The welding material for preparing a copper-stainless steel gradient structure according to claim 1, characterized in that: The method for preparing the welding material for preparing the transition layer near the stainless steel side comprises the following specific steps: Step 1: Weigh 40.0-50.0% Ni powder, 20.0-30.0% Cr powder, 5.0-8.0% Mo powder, 2.0-4.0% Nb powder, 2.0-4.0% Ag powder, 0.5-1.0% CeO2 powder, and the rest Fe powder according to mass percentage; Step 2: Place the powder weighed in step 1 in a vacuum heating furnace and heat it at a temperature of 200°C to 250°C for 1 hour to 3 hours to remove the crystal water in the powder; place the dried powder in a powder mixer and mix it thoroughly for 2 hours to 6 hours; Step 3: The powder prepared in step 2 is wrapped in a 430 steel strip using a flux-cored wire drawing machine. The aperture of the first drawing die is 2.6 mm. The powder filling rate of the welding material used to prepare the transition layer near the stainless steel side is controlled at 20 wt% to 23 wt%. Step 4: After the first drawing process is completed, the die aperture is reduced in sequence to finally obtain a flux-cored welding wire with a diameter of 1.0~1.2mm; Step 5: After the flux-cored wire is drawn, it is wound onto a wire reel by a wire winding machine and finally sealed in a flux-cored wire vacuum packaging bag for later use; The method for preparing the welding material for preparing the transition layer near the copper side comprises the following specific steps: Step 1: Weigh 20.0-30.0% Ni powder, 10.0-20.0% Ag powder, 10.0-20.0% Mo powder, 0.5-1.0% Y2O3 powder, and the rest Cu powder according to mass percentage; Step 2: The powder weighed in step 1 is placed in a vacuum heating furnace and heated at a temperature of 200°C to 220°C for 2 hours to 3 hours to remove the crystal water in the powder; the dried powder is placed in a powder mixer and fully mixed for 2 hours to 3 hours; Step 3: Use alcohol to remove grease from the surface of the copper strip. Then, use a flux-cored wire drawing machine to wrap the powder prepared in step 2 inside the copper strip. The aperture of the first drawing die is 2.6 mm. The powder filling rate of the welding material used to prepare the transition layer near the copper side is controlled at 30 wt% to 32 wt%. Step 4: After the first drawing process is completed, the die aperture is reduced in sequence to finally obtain a flux-cored welding wire with a diameter of 1.0~1.2mm; Step 5: After the flux-cored wire is drawn, it is wound onto a wire reel by a wire winding machine and finally sealed in a flux-cored wire vacuum packaging bag for use.

4. A method for preparing a copper-stainless steel gradient structure CMT using the copper-stainless steel gradient structure preparation welding material according to claim 1, characterized in that: The specific steps are as follows: (1) First, the welding material for preparing the near-stainless-steel-side transition layer is selected to prepare the near-steel-side transition layer on the surface of the stainless steel substrate, the CMT welding current is 180A~200A, the thickness of the cladding layer is 3mm~5mm, and the interlayer temperature is below 100℃; (2) Next, the copper side transition layer is prepared on the steel side transition layer using the welding material for preparing the copper side transition layer. The CMT welding current is 200A to 220A, the thickness of the cladding layer is 3mm to 5mm, and the interlayer temperature is below 100°C. (3) Finally, S201 welding wire was used to prepare the copper substrate by arc surfacing on the transition layer near the copper side. The CMT welding current was 220A~250A, the thickness of the surfacing layer was 10mm~15mm, and the surfacing was continuous without controlling the layer temperature.

Images