CN115852267A - High-strength high-conductivity low-expansion iron-nickel-molybdenum alloy wire and production method thereof - Google Patents
High-strength high-conductivity low-expansion iron-nickel-molybdenum alloy wire and production method thereof Download PDFInfo
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- 229910001182 Mo alloy Inorganic materials 0.000 title claims abstract description 23
- VAWNDNOTGRTLLU-UHFFFAOYSA-N iron molybdenum nickel Chemical compound [Fe].[Ni].[Mo] VAWNDNOTGRTLLU-UHFFFAOYSA-N 0.000 title claims abstract description 23
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 17
- 238000010438 heat treatment Methods 0.000 claims abstract description 62
- 238000000034 method Methods 0.000 claims abstract description 62
- 239000000956 alloy Substances 0.000 claims abstract description 58
- 229910045601 alloy Inorganic materials 0.000 claims abstract description 56
- 238000005242 forging Methods 0.000 claims abstract description 44
- 238000005096 rolling process Methods 0.000 claims abstract description 19
- 238000007670 refining Methods 0.000 claims abstract description 18
- 238000010622 cold drawing Methods 0.000 claims abstract description 15
- 229910052720 vanadium Inorganic materials 0.000 claims abstract description 15
- 230000001681 protective effect Effects 0.000 claims abstract description 14
- 230000032683 aging Effects 0.000 claims abstract description 12
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims abstract description 9
- 238000002844 melting Methods 0.000 claims abstract description 7
- 230000008018 melting Effects 0.000 claims abstract description 7
- 239000000126 substance Substances 0.000 claims abstract description 6
- 239000012535 impurity Substances 0.000 claims abstract description 5
- 229910052742 iron Inorganic materials 0.000 claims abstract description 4
- 229910052717 sulfur Inorganic materials 0.000 claims abstract description 4
- 229910052748 manganese Inorganic materials 0.000 claims abstract description 3
- 229910052698 phosphorus Inorganic materials 0.000 claims abstract description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 15
- 238000001816 cooling Methods 0.000 claims description 15
- 229910052804 chromium Inorganic materials 0.000 claims description 14
- 238000000227 grinding Methods 0.000 claims description 14
- 229910052799 carbon Inorganic materials 0.000 claims description 10
- 239000000463 material Substances 0.000 claims description 9
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 claims description 8
- 229910052757 nitrogen Inorganic materials 0.000 claims description 8
- 238000010079 rubber tapping Methods 0.000 claims description 8
- 229910003296 Ni-Mo Inorganic materials 0.000 claims description 7
- 238000005266 casting Methods 0.000 claims description 6
- 235000013339 cereals Nutrition 0.000 claims description 6
- 239000004576 sand Substances 0.000 claims description 6
- 238000010583 slow cooling Methods 0.000 claims description 6
- 238000005422 blasting Methods 0.000 claims description 5
- 238000004321 preservation Methods 0.000 claims description 5
- 229910000831 Steel Inorganic materials 0.000 claims description 4
- 229910052786 argon Inorganic materials 0.000 claims description 4
- 239000010959 steel Substances 0.000 claims description 4
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims description 3
- 230000003247 decreasing effect Effects 0.000 claims description 3
- 238000007599 discharging Methods 0.000 claims description 3
- 235000013312 flour Nutrition 0.000 claims description 3
- 239000007789 gas Substances 0.000 claims description 3
- 239000001257 hydrogen Substances 0.000 claims description 3
- 229910052739 hydrogen Inorganic materials 0.000 claims description 3
- 238000011068 loading method Methods 0.000 claims description 3
- 238000010309 melting process Methods 0.000 claims description 3
- 238000009987 spinning Methods 0.000 claims description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 3
- 229910001873 dinitrogen Inorganic materials 0.000 claims 1
- 239000002994 raw material Substances 0.000 abstract description 4
- 239000011651 chromium Substances 0.000 description 16
- 238000003723 Smelting Methods 0.000 description 9
- PXHVJJICTQNCMI-UHFFFAOYSA-N nickel Substances [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 9
- 239000000243 solution Substances 0.000 description 8
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 7
- 238000005728 strengthening Methods 0.000 description 7
- 238000001556 precipitation Methods 0.000 description 5
- 239000002893 slag Substances 0.000 description 5
- 239000006104 solid solution Substances 0.000 description 5
- 229910000531 Co alloy Inorganic materials 0.000 description 4
- KGWWEXORQXHJJQ-UHFFFAOYSA-N [Fe].[Co].[Ni] Chemical compound [Fe].[Co].[Ni] KGWWEXORQXHJJQ-UHFFFAOYSA-N 0.000 description 4
- 238000000137 annealing Methods 0.000 description 4
- 238000009826 distribution Methods 0.000 description 4
- UGKDIUIOSMUOAW-UHFFFAOYSA-N iron nickel Chemical compound [Fe].[Ni] UGKDIUIOSMUOAW-UHFFFAOYSA-N 0.000 description 4
- 239000002244 precipitate Substances 0.000 description 4
- 230000001276 controlling effect Effects 0.000 description 3
- 238000011049 filling Methods 0.000 description 3
- 229910052759 nickel Inorganic materials 0.000 description 3
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- 238000002360 preparation method Methods 0.000 description 3
- 238000003466 welding Methods 0.000 description 3
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 2
- 229910001309 Ferromolybdenum Inorganic materials 0.000 description 2
- 229910000628 Ferrovanadium Inorganic materials 0.000 description 2
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 238000001035 drying Methods 0.000 description 2
- PNXOJQQRXBVKEX-UHFFFAOYSA-N iron vanadium Chemical compound [V].[Fe] PNXOJQQRXBVKEX-UHFFFAOYSA-N 0.000 description 2
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- 150000001247 metal acetylides Chemical class 0.000 description 2
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- 241001062472 Stokellia anisodon Species 0.000 description 1
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- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 1
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Abstract
A high-strength high-conductivity low-expansion iron-nickel-molybdenum alloy wire and a production method thereof belong to the technical field of low-expansion alloys. The chemical components and the mass percentage content are as follows: c:0.09 to 0.32%, ni:36.5 to 38.7%, mo:0.7 to 2.3 percent of B, 0.1 to 0.2 percent of B, less than or equal to 0.1 percent of Mn, less than or equal to 0.01 percent of Ti, less than or equal to 0.2 percent of Si, less than or equal to 0.02 percent of P, less than or equal to 0.01 percent of S, and V:0.1 to 0.25% and 0.5 to 0.7% of Cr, the balance being iron and unavoidable impurities. The production method comprises the working procedures of vacuum melting, electroslag remelting secondary refining in protective atmosphere, forging, rolling, solution treatment, cold drawing and aging heat treatment. The iron-nickel-molybdenum alloy wire prepared by the method has the properties of high strength, low expansion, high conductivity and the like, and the Co-free component design is adopted, so that the cost of alloy raw materials can be greatly reduced.
Description
Technical Field
The invention belongs to the technical field of low-expansion alloys, and particularly relates to a high-strength high-conductivity low-expansion iron-nickel-molybdenum alloy wire and a production method thereof.
Background
The traditional low-expansion iron-nickel and iron-nickel-cobalt alloy has a lower linear expansion coefficient, and is widely applied to the fields of electric instruments, energy transportation, communication equipment and the like. In recent years, high-strength low-expansion iron-nickel and iron-nickel-cobalt alloys show great application potential in the fields of electric power transportation and aviation industry, and are key core materials without alternatives for preparing double-capacity wires, particularly in the field of electric power transmission. At present, the strengthening modes of iron-nickel and iron-nickel-cobalt alloy comprise solid solution strengthening, work hardening, aging strengthening and the like. However, in order to enhance the alloy strength, the above-mentioned strengthening method usually involves adding a large amount of alloy elements or producing a large amount of precipitated phases in the matrix, which affects the expansion coefficient and the electric conductivity of the low expansion alloy.
Disclosure of Invention
In order to solve the technical problems, the invention provides a high-strength high-conductivity low-expansion iron-nickel-molybdenum alloy wire and a production method thereof. The technical scheme adopted by the invention is as follows:
a high-strength high-conductivity low-expansion iron-nickel-molybdenum alloy wire comprises the following chemical components in percentage by mass: c:0.09 to 0.32%, ni:36.5 to 38.7%, mo:0.7 to 2.3 percent of B, 0.1 to 0.2 percent of B, less than or equal to 0.1 percent of Mn, less than or equal to 0.01 percent of Ti, less than or equal to 0.2 percent of Si, less than or equal to 0.02 percent of P, less than or equal to 0.01 percent of S, and V:0.1 to 0.25% and 0.5 to 0.7% of Cr, the balance being iron and unavoidable impurities.
The mass percentages of the four elements of C, mo, V and Cr satisfy the following relation:
C=0.6～1.1（0.045Mo +0.2 V+0.2 Cr）。
the iron-nickel-molybdenum alloy wire has a diameter of 2 to 6mm, tensile strength of 1150MPa or more, 20 ℃ conductivity of 2% or more IACS, room temperature-230 ℃ coefficient of thermal expansion of 2.4X 10 or less -6 /℃。
The production method of the high-strength high-conductivity low-expansion iron-nickel-molybdenum alloy wire comprises the working procedures of vacuum melting, electroslag remelting secondary refining in protective atmosphere, forging, rolling, solution treatment, cold drawing and aging heat treatment;
(1) A vacuum melting process: controlling the tapping casting temperature at 1460-1480 ℃;
(2) A secondary refining process of electroslag remelting in protective atmosphere: introducing high-purity argon into the electroslag furnace as protective gas 20-30 min before electroslag refining; the feeding period is divided into two sections of feeding, the voltage is 45-40V, the current is decreased within 6 k-4 kA, and each section of time is controlled to be 2-4 min;
(3) Forging: comprises the steps of heating, forging and cooling;
the heating step adopts three-stage heating, wherein the first stage is heating to 800-900 ℃, and keeping the temperature for 2-3 h; the second section is heated to 1180-1220 ℃, and the temperature is kept for 4-6 h; the third section is cooled to 1150-1170 ℃ along with the furnace, and the temperature is kept for 0.5-1 h;
the forging step adopts a one-way drawing mode, the forging temperature is 900-1100 ℃, the feeding amount L = 0.5-0.8 h in the forging process, the single reduction delta h is less than 18% h, and the end part forging feeding amount A is more than 0.4h; wherein h is the thickness of the forged piece and mm; delta h is single reduction, mm; a is the feeding amount of end forging, namely the feeding amount of the end during open forging, and is mm; forging to obtain a square billet with the cross section size of 135mm multiplied by 135 mm-150 mm multiplied by 150 mm;
the cooling step is to cool the billet to the surface temperature of less than or equal to 300 ℃;
(4) A rolling procedure: keeping the square billet at 1130-1180 ℃ for 2-3 h, then carrying out rough rolling, wherein the tapping temperature is more than or equal to 900 ℃; after the intermediate temperature is compensated to 950 ℃, finish rolling is carried out, the steel wire rod with the diameter of 8 to 12mm is rolled, and the spinning temperature is 800 to 850 ℃;
(5) A solution treatment process: introducing nitrogen into the heating furnace for protection; preheating a heating furnace before the wire rod is loaded into the furnace, heating to 800-850 ℃, preserving heat for more than 1h, and loading into the furnace before the wire rod is completely cooled; after charging, two-stage heating is adopted, the first stageHeating to 1050-1110 deg.c and maintaining for 0.5 hr; the second stage is heating to 1190-1220 deg.c for heat preservation for t 1 =1.5+0.1 D 1 Then discharging and water cooling; t is t 1 Keeping the temperature for h; d 1 The diameter of the rolled wire rod is mm;
(6) And (3) cold drawing: comprises the steps of peeling and drawing;
before peeling, shot blasting is carried out, and then peeling is carried out by adopting a turning tool peeling and double-abrasive-belt grinding mode;
in the drawing process, except for the requirement of no reduction rate in the last drawing, the reduction rates of other passes are controlled as follows: when D is present 2 When the thickness is more than 6mm, the single-pass surface reduction rate is 25-30%; when D is present 2 When the grain size is less than or equal to 6mm, the single-pass flour reduction rate is 20-25%; d 2 The diameter of the wire in the drawing process is mm;
(7) Aging heat treatment: under the protection of hydrogen atmosphere, heat treatment is carried out at 550-630 ℃, and the heat treatment time t 2 =0.25d，t 2 Heat treatment time, h; d is the diameter of the iron-nickel-molybdenum alloy wire material, mm.
In the protective atmosphere electroslag remelting secondary refining process, the melting speed is controlled to be 4.3 +/-0.3 kg/min in the electroslag refining process.
The forging procedure comprises a heating step, wherein the heating rate of the first section is 100-150 ℃/h, and the heating rate of the second section is 150-180 ℃/h; and cooling, namely adopting a slow cooling pit slow cooling or sand cooling mode.
The solution treatment process is carried out by adopting a well type heating furnace, and the ventilation volume of nitrogen per cubic meter is 4-6.5L/min according to the capacity of the heating furnace.
The solution treatment process comprises two-stage heating, wherein the heating rate of the first stage is 150-180 ℃/h; the temperature rise rate of the second section is 100-120 ℃/h.
In the cold drawing process, before peeling, shot blasting is carried out by using sand grains with the diameter of 1-1.5 mm to remove loose oxide skin on the surface; the total peeling removal amount of the turning tool is less than or equal to 0.4mm; in the double-abrasive-belt grinding process, the single-side grinding removal total amount H and the specifications of the front abrasive belt and the rear abrasive belt of the belt grinding machine meet the following requirements:
when H is less than 0.1mm, the front and rear abrasive belts are 240 meshes and 320 meshes respectively;
when H is more than or equal to 0.1 and less than or equal to 0.2mm, the front abrasive belt and the rear abrasive belt are respectively 180 meshes and 320 meshes;
when H is larger than 0.20mm, the front abrasive belt and the rear abrasive belt are respectively 80 meshes and 240 meshes.
In the cold drawing process, the total area reduction rate in the drawing process is more than or equal to 70 percent, and the drawn wire is a wire with the diameter of 2-6 mm.
The invention has the following components and process design ideas:
1. on the basis of the traditional low-expansion iron-nickel and iron-nickel-cobalt alloy, the content of C and the contents of main alloy elements Cr, mo and V are redesigned, so that the conductivity of the alloy is improved from the component perspective, and the thermal expansion coefficient is reduced; by controlling the proportion relation of the C element to Cr, mo and V, the alloy matrix can be ensured to form solid solution strengthening, and a stable and fine dispersion-distributed second phase is formed after subsequent solid solution and aging strengthening treatment of the alloy elements with proper proportion, so that the alloy strength is improved.
In the invention, C, cr, mo and V elements are added into the alloy, so that the alloy is subjected to solid solution strengthening, and a second phase which is fine and dispersed is precipitated by combining the processing method of the invention, thereby improving the strength of the alloy.
The addition of Cr and V elements can improve the strength of the alloy, but has a certain influence on the conductivity of the alloy. Therefore, in order to ensure high conductivity of the alloy, 1 to 2 kinds of V and Cr elements can be added, and V:0.1 to 0.25 percent of Cr and 0.5 to 0.7 percent of Cr.
In order to ensure the size and distribution state of precipitated phases in the alloy and avoid the change of the thermal expansion coefficient of the alloy caused by the precipitated phases, the addition amount of C must be regulated, and the addition amount of the carbon should meet the requirement that C = 0.6-1.1 (0.045Mo +0.2V + 0.2Cr), under the condition, the stable and controllable precipitation of Cr, mo and V carbides can be ensured, the excessive carbon is prevented from being dissociated, and the high strength of the alloy can be ensured, certain toughness can be kept and the thermal expansion coefficient of the alloy can be stabilized.
Wherein, the action and the proportion of each element are as follows:
c: carbon is an essential element of the carbide precipitates in the alloy, and determines the type, size, distribution state, and the like of the precipitates together with other precipitate phase elements. Therefore, the carbon element must ensure a certain lower limit so as to ensure the precipitation of the alloy; meanwhile, too much carbon causes too large carbide precipitates and free carbon, deteriorating the strength, toughness and thermal expansion properties of the alloy. The C content of the invention is designed to be 0.09-0.32%.
Ni: ni is an essential element for ensuring the low expansion property of the alloy. In the invention, the thermal expansion coefficient of the alloy is improved to a certain extent due to the addition of Cr, mo and V elements and the subsequent precipitation of carbide, so that the content of Ni is required to be properly increased, and the content of Ni is regulated to be 36.5-38.7 percent.
Mo: mo is a carbide precipitation element, and MoC and Mo can be formed by the processing technology of the invention 2 C and the like are dispersed and precipitated, so that the strength of the alloy is improved. However, the addition of Mo causes an increase in cost and an increase in expansion coefficient, and its upper limit is set to 2.3%.
V, cr: v is 0.1-0.25%, cr is 0.5-0.7%. V and Cr are carbide precipitation elements and can improve the alloy strength, but excessive addition can generate coarse carbides; meanwhile, V reduces the conductivity of the alloy, and Cr increases the expansion coefficient, so the invention provides that one or two of V and Cr can be added, and the content is strictly controlled.
B: the B element can improve the hot workability of the alloy.
Mn: mn, although improving the hot workability of the alloy, affects the thermal expansion properties and electrical conductivity of the alloy, and therefore the upper limit is set to 0.1%.
Ti: the upper limit of the amount of carbide formed by Ti and C is 0.01% because it is difficult to dissolve back in the alloy, and affects the toughness and conductivity of the alloy.
Si: si increases the expansion coefficient of the alloy, and the upper limit is set to 0.2%.
P is less than or equal to 0.02 percent, and S is less than or equal to 0.01 percent: p and S are used as harmful impurity elements, the content of the harmful impurity elements needs to be strictly controlled, and the lower the content, the better the content.
2. The purity of the alloy is ensured by vacuum smelting; after the electroslag remelting secondary refining in the protective atmosphere, the S content in the steel is in a lower level, and the cast structure of an electroslag ingot is finer and more compact than that of an intermediate frequency ingot, so that the electroslag remelting secondary refining method is greatly beneficial to subsequent processing. By adopting the two-stage feeding process, the integral solidification quality of the upper part of the electroslag ingot is greatly improved, the defects of obvious looseness, air holes, slag inclusion and the like of a solidification structure at the tail end of the steel ingot are ensured, and the feeding end is almost not required to be cut off. Therefore, the preparation method of vacuum smelting and protective atmosphere electroslag remelting secondary refining is used for controlling components, obtaining an electroslag ingot with fine and compact as-cast structure, and guaranteeing the yield of subsequent hot processing.
3. Under the alloy component system, the alloy is rapidly heated to 800-900 ℃ in the heating process and is insulated, so that the generation of a second phase structure in the inoculation of the alloy in a temperature region of 600-700 ℃ can be effectively avoided, and the deformation resistance of the alloy is improved. Meanwhile, large dendrites, structural segregation and large-sized primary precipitated phases exist in the cast structure. By high-temperature diffusion annealing at 1180-1220 ℃, the redissolution of a primary precipitated phase can be promoted, the dendritic crystal structure and the structure segregation are improved, the high-temperature thermoplasticity of the alloy is improved, and the high-temperature brittleness interval of the alloy is reduced;
meanwhile, the requirements of the rolling reduction, the forging feeding amount, the end forging feeding amount and the like in the forging method can greatly reduce the forging cracking phenomenon of large-size cast ingots in the cogging and finish forging processes, reduce the formation of surface defects such as surface crack, corner crack, folding and the like of a forging blank, contribute to the welding of pores, looseness and air holes in the cast ingots and improve the tissue quality of the forging blank.
4. By adopting the rolling method, the hot working performance of the alloy can be guaranteed, and the rolling yield can be improved; the oxidation phenomenon of the wire rod in the solid solution treatment can be greatly reduced by adopting a nitrogen protection mode; by adopting the hot charging of the wire rod and the heating furnace, the production efficiency can be greatly improved, and the energy consumption and the heating time can be reduced; the two-section heating mode can ensure that the temperature of the alloy can be uniformly raised in the heating furnace, the alloy is fully dissolved at the solution temperature, the tensile strength of the wire rod is reduced, and the subsequent drawing and aging heat treatment process is ensured to be smoothly carried out.
5. The alloy oxide skin which is difficult to remove by an acid washing method can be removed by adopting lathe tool peeling and double abrasive belt grinding; the cold-drawing and aging annealing process is different from the conventional cold-drawing, heat treatment and secondary cold-drawing process, the final process of the wire is the annealing process, and the hydrogen-nitrogen reducing atmosphere is used, so that the bright annealing effect on the surface of the wire can be achieved, the surface residue is further reduced, and the alloy wire with high surface quality is obtained.
The invention is suitable for producing Fe-Ni-Mo alloy wire with diameter of 2-6 mm, the tensile strength of the produced wire is more than or equal to 1150MPa, the electric conductivity at 20 ℃ is more than or equal to 2 percent IACS, and the thermal expansion coefficient at 15-230 ℃ is less than or equal to 2.4 multiplied by 10 -6 The alloy has the comprehensive properties of high strength, low expansion, high conductivity and the like, and can greatly reduce the cost of alloy raw materials by adopting a Co-free component design.
Detailed Description
The production method of the high-strength high-conductivity low-expansion iron-nickel-molybdenum alloy wire is suitable for producing wires with the diameter of 2-6 mm, and comprises the working procedures of vacuum smelting, protective atmosphere electroslag remelting secondary refining, forging, rolling, solution treatment, cold drawing and aging heat treatment; the specific process steps are as follows:
(1) A vacuum melting process: the method comprises the steps of raw material preparation, baking and drying, material distribution, smelting, tapping and pouring, and demoulding.
(1) Preparing raw materials: preparing a vacuum smelting furnace to smelt required alloy materials, and specifically comprising the following steps: industrial pure iron, electrolytic nickel plate, metal chromium, ferromolybdenum, ferrovanadium, ferroboron and low-nitrogen carburant;
(2) baking and drying: the ingot mold is baked for more than or equal to 12 hours at the temperature of 100-120 ℃;
(3) material distribution: laying a nickel plate on the bottom layer, adding chromium, ferromolybdenum and ferrovanadium, and then placing an iron rod and the nickel plate;
(4) smelting: when the vacuum degree in the furnace reaches 15Pa, the heating power is increased step by step until the furnace burden is completely melted down; after the furnace burden is completely melted down, filling argon, starting adding carbon powder and ferroboron, after the furnace burden is completely melted down, sampling and analyzing chemical components, and adding various alloy materials until the components meet the requirements;
(5) tapping and casting: the tapping casting temperature is controlled to be 1460-1480 ℃, and the specification of a casting die is phi 180-200 mm;
(6) demolding: demolding is carried out after casting for 12 h.
(2) A secondary refining process of electroslag remelting in protective atmosphere: comprises the steps of electroslag pre-preparation, electroslag smelting and electroslag ingot demoulding.
(1) Preparing before electroslag: preparing electrodes, dummy plates and slag;
an electrode: sawing and straightening the head and the tail of the ingot by using a sawing machine, then polishing the ingot body until the surface has no iron oxide scale, and welding the head of the ingot with a false electrode by using a welding rod;
a dummy bar plate: selecting a 30mm thick alloy slice with a flat end surface and no rust as a dummy plate;
slag charging: caF 55-65% of the optional ingredients (by weight) 2 、15～25%CaO、15～25%Al 2 O 3 The pre-melted slag is used as slag charge and is baked for more than or equal to 24 hours at the temperature of 600-700 ℃ before use.
(2) Electroslag smelting
The diameter ratio of the self-fluxing electrode rod to the crystallizer is a filling ratio, and the filling ratio is 0.6-0.7;
introducing high-purity argon into the electroslag furnace as protective gas 20-30 min before electroslag refining;
the steady-state melting speed is controlled to be 4.3 plus or minus 0.3kg/min by adjusting current and voltage in the electroslag refining process;
the feeding period is divided into two sections of feeding, the voltage is 45-40V, the current is decreased within 6 k-4 kA, and the time of each section is controlled to be 2-4 min.
(3) Demoulding of the electroslag ingot: and (4) stripping after electroslag smelting is completed for 2h, and then air cooling.
(3) Forging: comprises the steps of heating, forging and cooling;
the heating step adopts three-stage heating, wherein the first stage is heating to 800-900 ℃ at the speed of 100-150 ℃/h, and keeping the temperature for 2-3 h; in the second section, the temperature is raised to 1180-1220 ℃ at the speed of 150-180 ℃/h, and the temperature is kept for 4-6 h; the third section is cooled to 1150-1170 ℃ along with the furnace, and the temperature is kept for 0.5-1 h;
the forging step adopts a one-way drawing mode, the forging temperature is 900-1100 ℃, the feeding amount L = 0.5-0.8 h in the forging process, the single reduction delta h is less than 18% h, and the end part forging feeding amount A is more than 0.4h; wherein h is the thickness of the forging in the forging process and is mm; delta h is single reduction, mm; a is the feeding amount of end forging, namely the feeding amount of the end during open forging, and is mm; l, delta h and A are all related to the value of h (the thickness of the forged piece), the thickness of the forged piece is not a fixed value, and the thickness h of the forged piece can be changed every time when the forged piece is beaten, namely the corresponding L, delta h and A can be changed at any time and need to be adjusted in real time in the forging process; finally, forging to obtain a square billet with the cross section size of 135mm multiplied by 135 mm-150 mm multiplied by 150 mm;
and in the cooling step, a slow cooling pit slow cooling or sand cooling mode is adopted to cool the billet until the surface temperature of the billet is less than or equal to 300 ℃.
(4) A rolling procedure: and (3) polishing the surface of the forged blank, polishing the surface and the corner of the forged blank by using a grinding wheel polisher, removing corner cracks, surface hairlines and the like, and finally cutting off the head with the cracks. Then rolling by a continuous rolling mill, wherein the process comprises the following steps: keeping the square billet at 1130-1180 ℃ for 2-3 h, then carrying out rough rolling, wherein the tapping temperature is more than or equal to 900 ℃; after the intermediate temperature is compensated to 950 ℃, finish rolling is carried out, the wire rod with the diameter of 8 to 12mm is rolled, and the spinning temperature is 800 to 850 ℃.
(5) A solution treatment process: a well-type heating furnace is adopted, nitrogen is introduced into the heating furnace for protection, and the ventilation volume of the nitrogen per cubic meter is 4-6.5L/min according to the capacity of the heating furnace;
preheating a heating furnace before the wire rod is loaded into the furnace, heating to 800-850 ℃, preserving heat for more than 1h, and loading the wire rod into the furnace before the wire rod is completely cooled;
after charging, two-stage heating is adopted, wherein in the first stage, the temperature is increased to 1050-1110 ℃ at the speed of 150-180 ℃/h, and the temperature is kept for 0.5h; the second stage is to heat up to 1190 to 1220 ℃ at the speed of 100 to 120 ℃/h for heat preservation, and the heat preservation time t 1 =1.5+0.1 D 1 Then discharging and water cooling; t is t 1 Keeping the temperature for h; d 1 The diameter of the rolled wire rod is mm.
(6) And (3) cold drawing: comprises peeling and drawing steps;
before peeling, shot blasting is carried out by using sand grains with the diameter of 1-1.5 mm to remove loose oxide skin on the surface, and then peeling is carried out by adopting a turning tool peeling and double-abrasive-belt grinding mode; the total removal amount of the peeling of the turning tool is less than or equal to 0.4mm; in the double-abrasive-belt grinding process, the single-side grinding removal total amount H and the specifications of the front abrasive belt and the rear abrasive belt of the belt grinding machine meet the following requirements:
when H is less than 0.1mm, the front and rear abrasive belts are 240 meshes and 320 meshes respectively;
when H is more than or equal to 0.1 and less than or equal to 0.2mm, the front abrasive belt and the rear abrasive belt are respectively 180 meshes and 320 meshes;
when H is larger than 0.20mm, the front abrasive belt and the rear abrasive belt are respectively 80 meshes and 240 meshes;
in the drawing process, except for the requirement of no reduction rate in the last drawing, the reduction rates of other passes are controlled as follows: when D is present 2 When the thickness is more than 6mm, the single-pass area reduction rate is 25-30%; when D is present 2 When the grain size is less than or equal to 6mm, the single-pass flour reduction rate is 20-25%; d 2 The diameter of the wire in the drawing process is mm; the total area reduction rate is more than or equal to 70 percent, and the drawing is performed to form a wire with phi 2-6 mm.
(7) Aging heat treatment process: under the protection of hydrogen atmosphere, heat treatment is carried out at 550-630 ℃ for t 2 =0.25d，t 2 Heat treatment time, h; d is the diameter of the iron-nickel-molybdenum alloy wire material, mm.
The tensile strength of the Fe-Ni-Mo alloy wire obtained in the above-mentioned process is not less than 1150MPa, the electric conductivity at 20 deg.C is not less than 2%, IACS, and the thermal expansion coefficient at room temp. -230 deg.C is not more than 2.4X 10 -6 /℃。
The chemical components and the mass contents of the iron-nickel-molybdenum alloy wires in the embodiments 1 to 10 of the invention are shown in table 1, the parameter settings of each production process are shown in tables 2 to 5, and the mechanical properties of the produced iron-nickel-molybdenum alloy wires are shown in table 6.
TABLE 1 chemical composition of Fe-Ni-Mo alloy wire in examples (mass fraction%)
TABLE 2 vacuum melting and electroslag remelting process parameter settings for each example
TABLE 3 forging Process parameter settings for the examples
TABLE 4 Rolling and solution treatment Process parameter settings for the examples
TABLE 5 setting of the parameters of the cold-drawing and aging heat treatment process of each example
TABLE 6 Properties of Fe-Ni-Mo alloy wire in examples
Claims (10)
1. A high-strength high-conductivity low-expansion iron-nickel-molybdenum alloy wire is characterized by comprising the following chemical components in percentage by mass: c:0.09 to 0.32%, ni:36.5 to 38.7%, mo:0.7 to 2.3 percent of B, 0.1 to 0.2 percent of B, less than or equal to 0.1 percent of Mn, less than or equal to 0.01 percent of Ti, less than or equal to 0.2 percent of Si, less than or equal to 0.02 percent of P, less than or equal to 0.01 percent of S, and V:0.1 to 0.25% and 0.5 to 0.7% of Cr, the balance being iron and unavoidable impurities.
2. The high-strength high-conductivity low-expansion iron-nickel-molybdenum alloy wire material as claimed in claim 1, wherein the mass percentages of the four elements C, mo, V and Cr satisfy the following relation:
C=0.6～1.1（0.045Mo +0.2 V+0.2 Cr）。
3. a high strength high conductivity low expansion Fe-Ni-Mo alloy wire as claimed in claim 1 or 2Characterized in that the Fe-Ni-Mo alloy wire has a diameter of 2-6 mm, a tensile strength of not less than 1150MPa, an electric conductivity of not less than 2% IACS at 20 ℃, and a thermal expansion coefficient of not more than 2.4 x 10 at room temperature-230 ℃ -6 /℃。
4. A method for producing a high-strength high-conductivity low-expansion Fe-Ni-Mo alloy wire according to any one of claims 1 to 3, characterized by comprising the steps of vacuum melting, secondary refining of electroslag remelting in a protective atmosphere, forging, rolling, solution treatment, cold drawing and aging heat treatment;
(1) A vacuum melting process: controlling the tapping casting temperature at 1460-1480 ℃;
(2) A secondary refining process of electroslag remelting in protective atmosphere: introducing high-purity argon into the electroslag furnace as protective gas 20-30 min before electroslag refining; the feeding period is divided into two sections of feeding, the voltage is 45-40V, the current is decreased within 6 k-4 kA, and each section of time is controlled to be 2-4 min;
(3) Forging: comprises the steps of heating, forging and cooling;
the heating step adopts three-stage heating, wherein the first stage is heating to 800-900 ℃, and keeping the temperature for 2-3 h; the second stage is heating to 1180-1220 deg.c and maintaining for 4-6 hr; the third section is cooled to 1150-1170 ℃ along with the furnace, and the temperature is kept for 0.5-1 h;
the forging step adopts a one-way drawing mode, the forging temperature is 900-1100 ℃, the feeding amount L = 0.5-0.8 h in the forging process, the single reduction delta h is less than 18% h, and the end part forging feeding amount A is more than 0.4h; wherein h is the thickness of the forged piece and mm; delta h is single reduction, mm; a is the feeding amount of end forging, namely the feeding amount of the end during open forging, and is mm; forging to obtain a square billet with the cross section size of 135mm multiplied by 135 mm-150 mm multiplied by 150 mm;
the cooling step is to cool the billet to the surface temperature of less than or equal to 300 ℃;
(4) A rolling procedure: keeping the square billet at 1130-1180 ℃ for 2-3 h, then carrying out rough rolling, wherein the tapping temperature is more than or equal to 900 ℃; after the intermediate temperature is compensated to 950 ℃, finish rolling is carried out, the steel wire rod with the diameter of 8 to 12mm is rolled, and the spinning temperature is 800 to 850 ℃;
(5) A solution treatment process: introducing nitrogen into the heating furnaceProtection is carried out; preheating a heating furnace before the wire rod is loaded into the furnace, heating to 800-850 ℃, preserving heat for more than 1h, and loading the wire rod into the furnace before the wire rod is completely cooled; after charging, two-stage heating is adopted, wherein the first stage is heating to 1050-1110 ℃, and heat preservation is carried out for 0.5h; the second stage is heating to 1190-1220 deg.c for heat preservation for t 1 =1.5+0.1 D 1 Then discharging from the furnace and cooling by water; t is t 1 Keeping the temperature for h; d 1 The diameter of the rolled wire rod is mm;
(6) And (3) cold drawing: comprises peeling and drawing steps;
before peeling, shot blasting is carried out, and then peeling is carried out by adopting a turning tool peeling and double-abrasive-belt grinding mode;
in the drawing process, except for the requirement of no reduction rate in the last drawing, the reduction rates of other passes are controlled as follows: when D is present 2 When the thickness is more than 6mm, the single-pass surface reduction rate is 25-30%; when D is present 2 When the grain size is less than or equal to 6mm, the single-pass flour reduction rate is 20-25%; d 2 The diameter of the wire in the drawing process is mm;
(7) Aging heat treatment process: under the protection of hydrogen atmosphere, heat treatment is carried out at 550-630 ℃ for t 2 =0.25d，t 2 Heat treatment time, h; d is the diameter of the iron-nickel-molybdenum alloy wire material, mm.
5. The method for producing the iron-nickel-molybdenum alloy wire with high strength, high conductivity and low expansion as claimed in claim 4, wherein in the secondary refining step of electroslag remelting in the protective atmosphere, the melting speed is controlled to be 4.3 +/-0.3 kg/min in the electroslag refining process.
6. The method for producing a high-strength high-conductivity low-expansion iron-nickel-molybdenum alloy wire according to claim 5, wherein the forging step, the heating step, the first stage has a temperature rise rate of 100 to 150 ℃/h, and the second stage has a temperature rise rate of 150 to 180 ℃/h; and cooling, namely adopting a slow cooling pit slow cooling or sand cooling mode.
7. The method for producing a high-strength high-conductivity low-expansion iron-nickel-molybdenum alloy wire according to claim 6, wherein the solution treatment step is carried out using a shaft furnace, and the amount of nitrogen gas per cubic meter is 4 to 6.5L/min depending on the capacity of the furnace.
8. The method for producing a high-strength high-conductivity low-expansion iron-nickel-molybdenum alloy wire according to claim 7, wherein the solution treatment step is a two-stage heating, and the temperature rise rate of the first stage is 150 to 180 ℃/h; the temperature rise rate of the second section is 100-120 ℃/h.
9. The method for producing the iron-nickel-molybdenum alloy wire with high strength, high conductivity and low expansion as claimed in claim 8, wherein in the cold drawing step, before peeling, 1-1.5 mm sand grains are used for shot blasting to remove loose oxide scales on the surface; the total removal amount of the peeling of the turning tool is less than or equal to 0.4mm; in the double-abrasive-belt grinding process, the single-side grinding removal total amount H and the specifications of the front abrasive belt and the rear abrasive belt of the belt grinding machine meet the following requirements:
when H is less than 0.1mm, the front and rear abrasive belts are 240 meshes and 320 meshes respectively;
when H is more than or equal to 0.1 and less than or equal to 0.2mm, the front abrasive belt and the rear abrasive belt are respectively 180 meshes and 320 meshes;
when H is larger than 0.20mm, the front abrasive belt and the rear abrasive belt are respectively 80 meshes and 240 meshes.
10. The production method of the high-strength high-conductivity low-expansion iron-nickel-molybdenum alloy wire material according to any one of claims 1 to 9, characterized in that in the cold-drawing process, the total reduction rate is not less than 70% in the drawing process, and the drawn wire material is a wire material with the diameter of 2-6 mm.
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