CN113245393A - Preparation method of bar for EMS247 austenitic gas valve steel hot extrusion - Google Patents
Preparation method of bar for EMS247 austenitic gas valve steel hot extrusion Download PDFInfo
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- CN113245393A CN113245393A CN202110498232.4A CN202110498232A CN113245393A CN 113245393 A CN113245393 A CN 113245393A CN 202110498232 A CN202110498232 A CN 202110498232A CN 113245393 A CN113245393 A CN 113245393A
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- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 49
- 239000010959 steel Substances 0.000 title claims abstract description 49
- 238000001192 hot extrusion Methods 0.000 title claims abstract description 17
- 238000002360 preparation method Methods 0.000 title claims abstract description 17
- 239000000956 alloy Substances 0.000 claims abstract description 20
- 238000009749 continuous casting Methods 0.000 claims abstract description 20
- 238000000034 method Methods 0.000 claims abstract description 20
- 238000007670 refining Methods 0.000 claims abstract description 20
- 238000005096 rolling process Methods 0.000 claims abstract description 19
- 229910045601 alloy Inorganic materials 0.000 claims abstract description 16
- 229910001566 austenite Inorganic materials 0.000 claims abstract description 15
- 238000000137 annealing Methods 0.000 claims abstract description 14
- 238000003723 Smelting Methods 0.000 claims abstract description 11
- 239000010953 base metal Substances 0.000 claims abstract description 7
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 7
- 238000005266 casting Methods 0.000 claims abstract description 7
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- 229910000604 Ferrochrome Inorganic materials 0.000 claims abstract description 4
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- 238000002844 melting Methods 0.000 claims abstract description 4
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- 230000005540 biological transmission Effects 0.000 claims description 29
- 238000010438 heat treatment Methods 0.000 claims description 26
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- 238000005498 polishing Methods 0.000 claims description 9
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- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 6
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- 238000010583 slow cooling Methods 0.000 claims description 3
- 238000009987 spinning Methods 0.000 claims description 3
- 238000003756 stirring Methods 0.000 claims description 3
- 210000003781 tooth socket Anatomy 0.000 claims description 3
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- 238000004519 manufacturing process Methods 0.000 abstract description 6
- 230000007547 defect Effects 0.000 abstract description 3
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- 238000005554 pickling Methods 0.000 description 2
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- 238000007792 addition Methods 0.000 description 1
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES OR PROFILES, OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
- B21C37/00—Manufacture of metal sheets, bars, wire, tubes or like semi-manufactured products, not otherwise provided for; Manufacture of tubes of special shape
- B21C37/04—Manufacture of metal sheets, bars, wire, tubes or like semi-manufactured products, not otherwise provided for; Manufacture of tubes of special shape of bars or wire
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21B—ROLLING OF METAL
- B21B1/00—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations
- B21B1/16—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling wire rods, bars, merchant bars, rounds wire or material of like small cross-section
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D3/00—Straightening or restoring form of metal rods, metal tubes, metal profiles, or specific articles made therefrom, whether or not in combination with sheet metal parts
- B21D3/02—Straightening or restoring form of metal rods, metal tubes, metal profiles, or specific articles made therefrom, whether or not in combination with sheet metal parts by rollers
- B21D3/05—Straightening or restoring form of metal rods, metal tubes, metal profiles, or specific articles made therefrom, whether or not in combination with sheet metal parts by rollers arranged on axes rectangular to the path of the work
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D43/00—Feeding, positioning or storing devices combined with, or arranged in, or specially adapted for use in connection with, apparatus for working or processing sheet metal, metal tubes or metal profiles; Associations therewith of cutting devices
- B21D43/02—Advancing work in relation to the stroke of the die or tool
- B21D43/04—Advancing work in relation to the stroke of the die or tool by means in mechanical engagement with the work
- B21D43/08—Advancing work in relation to the stroke of the die or tool by means in mechanical engagement with the work by rollers
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
- B22D11/16—Controlling or regulating processes or operations
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
- C21D1/26—Methods of annealing
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D6/00—Heat treatment of ferrous alloys
- C21D6/002—Heat treatment of ferrous alloys containing Cr
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
- C21D8/06—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of rods or wires
- C21D8/065—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of rods or wires of ferrous alloys
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
- C21D9/52—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for wires; for strips ; for rods of unlimited length
- C21D9/525—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for wires; for strips ; for rods of unlimited length for wire, for rods
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B9/00—General processes of refining or remelting of metals; Apparatus for electroslag or arc remelting of metals
- C22B9/16—Remelting metals
- C22B9/18—Electroslag remelting
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- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Manufacturing & Machinery (AREA)
- Heat Treatment Of Steel (AREA)
Abstract
The invention discloses a preparation method of a bar for EMS247 austenitic gas valve steel hot extrusion, which comprises the following steps: the method comprises the following steps: adding alloy materials such as scrap steel, high-carbon ferrochrome and the like into an electric arc furnace, and melting and primary smelting the alloy; step two: smelting in a ladle refining furnace; step three: vacuum refining in a VD furnace; step four: continuously casting the arc square billet by a continuous casting machine to obtain an electroslag base metal blank; step five: electroslag remelting; step six: high-speed wire rolling to obtain 85Cr18Mo2V hot-rolled wire rods; step seven: annealing; the invention adopts a metallurgy method of continuous casting base metal and electroslag remelting to produce the billet, overcomes the difficult problem that austenite has large high-temperature deformation resistance and is difficult to be continuously cast, improves the form and distribution condition of primary carbides, reduces various segregation, looseness and other metallurgical defects in the billet, effectively refines the structure of the original billet, saves energy digestion, reduces the production cost, improves the labor condition and lightens the labor intensity of workers.
Description
Technical Field
The invention belongs to the technical field of metal processing, and particularly relates to a preparation method of a bar for EMS247 austenitic air valve steel hot extrusion.
Background
EMS247(51Cr8Si2) austenite valve steel, corresponding to Japanese brand SUH11, is applied to exhaust valve materials of internal combustion engine valve engines, mainly used as intake valve materials, the materials have high carbon content, contain chromium and silicon, belong to medium carbon austenite materials, have quite wear-resisting and corrosion-resisting functions, and are currently produced in China, EMS247(51Cr8Si2) austenite valve steel is used for hot extruded rods and is provided for customers to use, the original electric upsetting manufacturing method is replaced, and the method has the advantages of optimized cost and low resource consumption.
A straightener on the market needs to convey wire rods manually, the labor intensity of workers is greatly improved, the distance between a first guide wheel and a second guide wheel cannot be adjusted, the wire rods cannot be conveyed when the diameter of the wire rods is changed, and the straightening of the wire rods is not facilitated.
Disclosure of Invention
The invention aims to provide a preparation method of a rod for EMS247 austenitic air valve steel hot extrusion, which aims to solve the problems that a straightener in the market proposed in the background art needs to convey a wire rod manually, the labor intensity of workers is greatly improved, the distance between a first guide wheel and a second guide wheel cannot be adjusted, the wire rod cannot be conveyed when the diameter of the wire rod is changed, and the straightening of the wire rod is not facilitated.
In order to achieve the purpose, the invention provides the following technical scheme: a preparation method of a bar for EMS247 austenitic air valve steel hot extrusion comprises the following specific steps:
the method comprises the following steps: adding alloy materials such as scrap steel, high-carbon ferrochrome and the like into an electric arc furnace, and melting and primary smelting the alloy;
step two: smelting in a ladle refining furnace;
step three: vacuum refining in a VD furnace;
step four: continuously casting the arc square billet by a continuous casting machine to obtain an electroslag base metal blank;
step five: electroslag remelting;
step six: high-speed wire rolling to obtain 85Cr18Mo2V hot-rolled wire rods;
step seven: annealing;
step eight: straightening;
step nine: and (6) polishing, inspecting and warehousing.
Preferably, the EBT tapping temperature of the alloy in the step one is more than or equal to 1600 ℃, the P is less than or equal to 0.040 percent, and the specific smelting process of the ladle refining furnace in the step two is as follows:
s1: adjusting alloy components, heating, refining and deoxidizing;
s2: sampling and analyzing, and after all alloy components reach the national standard requirement, tapping and transferring to a VD station.
Preferably, the vacuum refining in the VD furnace in the third step comprises the following specific steps:
SS 1: removing slag before entering a VD furnace, refining the alloy in the VD furnace after removing the slag, vacuumizing, and keeping the time for more than or equal to 12 minutes when the vacuum degree reaches 67 Pa;
SS 2: after breaking vacuum, measuring temperature, sampling and analyzing, adding a covering agent, and keeping blowing argon weakly;
SS 3: when the sedation time is more than or equal to 10 minutes and the temperature is more than or equal to 1500 ℃, transferring to a platform of a continuous casting machine;
and the continuous casting machine platform is continuously cast by using an arc-shaped square billet continuous casting machine.
Preferably, the arc-shaped billet continuous casting machine in the fourth step needs to pay attention to the following three points:
firstly, the method comprises the following steps: a combined mode of a crystallizer and electromagnetic stirring at the tail end is adopted during casting, the target temperature is required to be controlled to 1450-1470 ℃, and the target pulling speed is required to be controlled to be 1.0-1.2 m/min;
II, secondly: the cooling control mode is that the secondary cooling area adopts a three-section type area water distribution mode, and the specific water quantity is automatically matched along with the pulling speed;
thirdly, the method comprises the following steps: cutting to length during blank discharging, and stacking in air cooling.
Preferably, the electroslag remelting in the fifth step comprises the following specific steps:
a1: welding an electroslag base material blank and a false electrode, and carrying out electroslag remelting to obtain an electroslag steel ingot;
a2: after the electroslag steel ingot is demoulded, the electroslag steel ingot enters a sand pit for slow cooling within 15 minutes;
wherein, the electroslag remelting current is 5000-6000A, the voltage is 50-55V, and the remelting time is controlled to be 120-160 minutes; and (3) burying sand and slowly cooling the steel ingot, keeping the steel ingot slowly cooled to room temperature, taking the steel ingot out of a pit, and performing transition rolling.
Preferably, the heating instrument for high-speed wire rolling in the sixth step is a push-type heating furnace or a stepping heating furnace, and the heating temperature of the bloom is controlled according to the following requirements: a preheating section: at most 920 ℃; a heating section: 920-1020 ℃, soaking section: 1130-1150 ℃; the initial rolling temperature: 1120-1140 ℃, the final rolling and spinning temperature is controlled to be more than or equal to 900 ℃, the finish rolling speed is controlled to be 28-35 m/s, air cooling is carried out, the steel wire enters a coil collecting line for collection, the steel wire is transferred to a heat treatment process, and the out-of-roundness of the hot rolled wire rod is controlled to be +/-0.15 mm.
Preferably, in the step seven, the annealing refers to annealing the 85Cr18Mo2V hot-rolled wire rod within 6 hours, the annealing adopts a trolley type electric furnace, the temperature is increased to 850 ℃ along with the furnace, the temperature-increasing time is more than or equal to 4 hours, the temperature is kept for 4-4.5 hours when the temperature reaches 850 +/-10 ℃, and then the wire rod is cooled to below 600 ℃ along with the furnace and then cooled by air; straightening in the step eight, namely after the 85Cr18Mo2V hot-rolled wire rod is subjected to annealing heat treatment, soaking the 85Cr18Mo2V hot-rolled wire rod into a lime coating solution for a moment, pulling out, naturally drying, and straightening by a straightener on the basis of drying and whitening of a surface coating; and the step nine, polishing, inspection and warehousing means that the straightened 85Cr18Mo2V hot-rolled wire rod is subjected to grinding processing, centerless grinding is adopted for polishing, the steps are coarse grinding and fine grinding, NDT nondestructive inspection is carried out on the polished 85Cr18Mo2V hot-rolled wire rod, and the product is warehoused after being inspected to be qualified.
Preferably, the straightening machine in the eighth straightening step comprises a supporting table, a first transmission box is arranged at the edge position of the left side of the upper end of the supporting table, an adjusting disc is movably mounted at the left end of the first transmission box, one end of the adjusting disc is connected with a connecting rod, four groups of gears are arranged on the connecting rod, a straightening box and a second transmission box are arranged at the right side, located on the first transmission box, of the upper end of the supporting table, and the second transmission box is located on the right side of the straightening box.
Preferably, four groups of movable holes are formed in the front end of the first transmission case, two groups of limiting rods are arranged in each movable hole, a movable plate is movably mounted in each movable hole, a second guide wheel is arranged at the front end of each movable plate, a first guide wheel is arranged below the second guide wheel, one end of the first guide wheel is connected with a transmission shaft, and the other end of the transmission shaft is connected with a motor.
Preferably, two sets of spacing holes have been seted up to the upper end of fly leaf, spacing hole agrees with mutually with the gag lever post, and the rear end of fly leaf is connected with the connecting plate, a plurality of groups's tooth's socket has been seted up on the connecting plate, the tooth's socket meshes with the gear mutually, the export has been seted up to the left end of straightening case, the import has been seted up to the right-hand member of straightening case, the inside left side of straightening case sets up a plurality of groups of horizon wheel, every group the horizon wheel divide into two from top to bottom, the inside right side of straightening case is provided with the vertical wheel of a plurality of groups, every group two around vertical wheel divide into, and vertical wheel is crisscross the setting each other, the equal movable mounting of horizon wheel and vertical wheel is in the straightening case.
Compared with the prior art, the invention has the beneficial effects that:
1. the invention adopts a metallurgy method of continuous casting base metal and electroslag remelting to produce the billet, overcomes the difficult problem that the austenite has large high-temperature deformation resistance and is difficult to be continuously cast, improves the form and distribution condition of primary carbides, reduces various segregation, looseness and other metallurgical defects in the billet, effectively refines the structure of the original billet, saves energy digestion and reduces the production cost.
2. The invention adopts electroslag steel ingot to be formed by one heating, which obviously improves the production efficiency, and the wire rod is ground and processed without the pollution of pickling solution, thereby achieving the purposes of reducing cost and improving efficiency, improving the labor condition and reducing the labor intensity of workers.
3. This straightening machine can make the gear on the connecting rod rotate through rotating the adjustment disk to connecting plate with gear engaged with can drive the fly leaf and reciprocate in the movable hole, thereby can adjust the distance between leading wheel two and the leading wheel one, can be applicable to the wire rod of different diameters, conveniently transports the wire rod, and the use is simple, can avoid manual transport, is favorable to the straightening of wire rod.
Drawings
Fig. 1 is a schematic view of the overall structure of the present invention.
Fig. 2 is a cross-sectional view of a first gear box of the invention.
Fig. 3 is a schematic diagram of the structure of the movable plate of the present invention.
Figure 4 is a top view of the straightening box of the present invention.
In the figure: 1. a support table; 2. an outlet; 3. a horizontal wheel; 4. a vertical wheel; 5. an adjusting disk; 6. a first transmission case; 8. a straightening box; 9. a movable plate; 10. a limiting rod; 11. a gear; 12. a connecting rod; 13. a first guide wheel; 14. a drive shaft; 15. a motor; 16. a second guide wheel; 17. a limiting hole; 18. a connecting plate; 19. a tooth socket; 20. an inlet; 21. and (4) a movable hole.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Example 1
A preparation method of a bar for EMS247 austenitic air valve steel hot extrusion comprises the following specific steps:
the method comprises the following steps: adding alloy materials such as scrap steel, high-carbon ferrochrome and the like into an electric arc furnace, and melting and primary smelting the alloy;
step two: smelting in a ladle refining furnace;
step three: vacuum refining in a VD furnace;
step four: continuously casting the arc square billet by a continuous casting machine to obtain an electroslag base metal blank;
step five: electroslag remelting;
step six: high-speed wire rolling to obtain 85Cr18Mo2V hot-rolled wire rods;
step seven: annealing;
step eight: straightening;
step nine: and (6) polishing, inspecting and warehousing.
The EBT tapping temperature of the alloy in the first step is more than or equal to 1600 ℃, the P is less than or equal to 0.040 percent, and the specific smelting process of the ladle refining furnace in the second step is as follows:
s1: adjusting alloy components, heating, refining and deoxidizing;
s2: sampling and analyzing, and after all alloy components reach the national standard requirement, tapping and transferring to a VD station;
the concrete performance of meeting the national standard requirements is as follows: the white slag is kept for more than or equal to 10 minutes and the temperature is more than or equal to 1600 ℃.
The vacuum refining in the VD furnace in the third step comprises the following specific steps:
SS 1: removing slag before entering a VD furnace, refining the alloy in the VD furnace after removing the slag, vacuumizing, and keeping the time for more than or equal to 12 minutes when the vacuum degree reaches 67 Pa;
SS 2: after breaking vacuum, measuring temperature, sampling and analyzing, adding a covering agent, and keeping blowing argon weakly;
SS 3: when the sedation time is more than or equal to 10 minutes and the temperature is more than or equal to 1500 ℃, transferring to a platform of a continuous casting machine;
wherein, the continuous casting machine platform selects an arc square billet continuous casting machine for continuous casting.
In the fourth step, the continuous casting of the arc-shaped square billet continuous casting machine needs to pay attention to the following three points:
firstly, the method comprises the following steps: a combined mode of a crystallizer and electromagnetic stirring at the tail end is adopted during casting, the target temperature is required to be controlled to 1450-1470 ℃, and the target pulling speed is required to be controlled to be 1.0-1.2 m/min;
II, secondly: the cooling control mode is that the secondary cooling area adopts a three-section type area water distribution mode, and the specific water quantity is automatically matched along with the pulling speed;
thirdly, the method comprises the following steps: cutting to length during blank discharging, and stacking in air cooling.
The electroslag remelting in the fifth step comprises the following specific steps:
a1: welding an electroslag base material blank and a false electrode, and carrying out electroslag remelting to obtain an electroslag steel ingot;
a2: after the electroslag steel ingot is demoulded, the electroslag steel ingot enters a sand pit for slow cooling within 15 minutes;
wherein, the electroslag remelting current is 5000-6000A, the voltage is 50-55V, and the remelting time is controlled to be 120-160 minutes; and (3) burying sand and slowly cooling the steel ingot, keeping the steel ingot slowly cooled to room temperature, taking the steel ingot out of a pit, and performing transition rolling.
In the sixth step, the heating instrument for the high-speed rolling is a push type heating furnace or a stepping type heating furnace, and the heating temperature of the bloom is controlled according to the following requirements: a preheating section: at most 920 ℃; a heating section: 920-1020 ℃, soaking section: 1130-1150 ℃; the initial rolling temperature: 1120-1140 ℃, the final rolling and spinning temperature is controlled to be more than or equal to 900 ℃, the finish rolling speed is controlled to be 28-35 m/s, air cooling is carried out, the steel wire enters a coil collecting line for collection, the steel wire is transferred to a heat treatment process, and the out-of-roundness of the hot rolled wire rod is controlled to be +/-0.15 mm.
Annealing in the seventh step means that the 85Cr18Mo2V hot-rolled wire rod is annealed within 6 hours, the annealing adopts a trolley type electric furnace, the temperature is increased to 850 ℃ along with the furnace, the temperature rise time is more than or equal to 4 hours, the temperature is kept for 4-4.5 hours when the temperature reaches 850 +/-10 ℃, and then the wire rod is cooled to below 600 ℃ along with the furnace and then is cooled by air; straightening in the step eight, namely after the 85Cr18Mo2V hot-rolled wire rod is subjected to annealing heat treatment, soaking the 85Cr18Mo2V hot-rolled wire rod into a lime coating solution for a moment, pulling out, naturally drying, and straightening by a straightener on the basis of drying and whitening of a surface coating; and step nine, polishing, inspecting and warehousing represent that the straightened 85Cr18Mo2V hot-rolled wire rod is subjected to grinding processing, centerless grinding is adopted for polishing, the steps are coarse grinding and fine grinding, NDT nondestructive inspection is carried out on the polished 85Cr18Mo2V hot-rolled wire rod, and the product is warehoused after being inspected to be qualified.
Through the technical scheme: the invention adopts a metallurgy method of continuous casting base metal and electroslag remelting to produce the billet, overcomes the difficult problem that the austenite has large high-temperature deformation resistance and is difficult to be continuously cast, improves the form and distribution condition of primary carbides, reduces various segregation, looseness and other metallurgical defects in the billet, effectively refines the structure of the original billet, saves energy digestion and reduces the production cost; the invention adopts electroslag steel ingot to be formed by one heating, which obviously improves the production efficiency, and the wire rod is ground and processed without the pollution of pickling solution, thereby achieving the purposes of reducing cost and improving efficiency, improving the labor condition and reducing the labor intensity of workers.
Example 2
Referring to fig. 1-4, the straightening machine of the present embodiment includes a supporting table 1, a first transmission box 6 is disposed at a left edge of an upper end of the supporting table 1, a first adjustment plate 5 is movably mounted at a left end of the first transmission box 6, one end of the first adjustment plate 5 is connected to a connection rod 12, four sets of gears 11 are disposed on the connection rod 12, a straightening box 8 and a second transmission box are disposed at a right side of the first transmission box 6 and at an upper end of the supporting table 1, and the second transmission box is disposed at a right side of the straightening box 8.
Referring to fig. 2, four sets of movable holes 21 are formed in the front end of the first transmission case 6, two sets of limiting rods 10 are disposed in the movable holes 21, a movable plate 9 is movably mounted in the movable holes 21, a second guide wheel 16 is disposed at the front end of the movable plate 9, a first guide wheel 13 is disposed below the second guide wheel 16, one end of the first guide wheel 13 is connected to a transmission shaft 14, and the other end of the transmission shaft 14 is connected to a motor 15.
Referring to fig. 3-4, two sets of limiting holes 17 are formed in the upper end of the movable plate 9, the limiting holes 17 are matched with the limiting rods 10, the rear end of the movable plate 9 is connected with a connecting plate 18, a plurality of sets of tooth grooves 19 are formed in the connecting plate 18, the tooth grooves 19 are meshed with the gears 11, an outlet 2 is formed in the left end of the straightening box 8, an inlet 20 is formed in the right end of the straightening box 8, a plurality of sets of horizontal wheels 3 are arranged on the left side of the inside of the straightening box 8, each set of horizontal wheels 3 is divided into an upper horizontal wheel and a lower horizontal wheel, a plurality of sets of vertical wheels 4 are arranged on the right side of the inside of the straightening box 8, each set of vertical wheels 4 is divided into a front vertical wheel and a rear vertical wheel, the vertical wheels 4 are arranged in a staggered mode, and the horizontal wheels 3 and the vertical wheels 4 are movably installed in the straightening box 8.
Specifically, when using, through rotating adjustment disk 5, can make gear 11 on the connecting rod 12 rotate to connecting plate 18 with gear 11 meshing can drive fly leaf 9 and reciprocate in activity hole 21, thereby can adjust the distance between leading wheel two 16 and the leading wheel 13, can be applicable to the wire rod of different diameters, conveniently transports the wire rod, and the user mode is simple, can avoid manual transport, is favorable to the straightening of wire rod.
The working principle of the straightener is as follows: for the straightening machine, firstly, the wire rod passes through a second transmission box on the support table 1, the wire rod on the second transmission box enters a straightening box 8 from an inlet 20, the wire rod can be straightened after the interaction of a horizontal wheel 3 and a vertical wheel 4, the straightened wire rod enters a first transmission box 6 through an outlet 2, the first guide wheel 13 is connected with a motor 15 through a transmission shaft 14, the motor 15 can rotate the first guide wheel 13 after being started, so that the wire rod on the first guide wheel 13 linearly moves between the first guide wheel 13 and a second guide wheel 16, a gear 11 on a connecting rod 12 can rotate through rotating an adjusting disc 5, a connecting plate 18 meshed with the gear 11 through a tooth groove 19 can drive a movable plate 9 to move up and down, the movable plate 9 can move up and down through a limiting hole 17 in a movable hole 21 in cooperation with a limiting rod 10, so that the distance between the second guide wheel 16 and the first guide wheel 13 can be adjusted, the wire rod straightening machine can be suitable for wire rods with different diameters, is convenient to transport the wire rods, is simple in use mode, can avoid manual conveying, and is favorable for straightening the wire rods.
In the description herein, references to the description of "one embodiment," "an example," "a specific example" or the like are intended to mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
The foregoing is merely exemplary and illustrative of the present invention and various modifications, additions and substitutions may be made by those skilled in the art to the specific embodiments described without departing from the scope of the invention as defined in the following claims.
Claims (10)
1. A preparation method of a bar for EMS247 austenitic air valve steel hot extrusion is characterized by comprising the following specific steps:
the method comprises the following steps: adding alloy materials such as scrap steel, high-carbon ferrochrome and the like into an electric arc furnace, and melting and primary smelting the alloy;
step two: smelting in a ladle refining furnace;
step three: vacuum refining in a VD furnace;
step four: continuously casting the arc square billet by a continuous casting machine to obtain an electroslag base metal blank;
step five: electroslag remelting;
step six: high-speed wire rolling to obtain 85Cr18Mo2V hot-rolled wire rods;
step seven: annealing;
step eight: straightening;
step nine: and (6) polishing, inspecting and warehousing.
2. The preparation method of the EMS247 austenite valve steel bar for hot extrusion as claimed in claim 1, wherein EBT tapping temperature of the alloy in the first step is not less than 1600 ℃, P is not more than 0.040%, and the specific smelting process in the ladle refining furnace in the second step is as follows:
s1: adjusting alloy components, heating, refining and deoxidizing;
s2: sampling and analyzing, and after all alloy components reach the national standard requirement, tapping and transferring to a VD station.
3. The preparation method of the EMS247 austenite valve steel bar for hot extrusion, according to claim 1, is characterized in that the specific steps of the VD furnace vacuum refining in the third step are as follows:
SS 1: removing slag before entering a VD furnace, refining the alloy in the VD furnace after removing the slag, vacuumizing, and keeping the time for more than or equal to 12 minutes when the vacuum degree reaches 67 Pa;
SS 2: after breaking vacuum, measuring temperature, sampling and analyzing, adding a covering agent, and keeping blowing argon weakly;
SS 3: when the sedation time is more than or equal to 10 minutes and the temperature is more than or equal to 1500 ℃, transferring to a platform of a continuous casting machine;
and the continuous casting machine platform is continuously cast by using an arc-shaped square billet continuous casting machine.
4. The preparation method of the EMS247 austenite valve steel bar for hot extrusion as claimed in claim 3, wherein the arc-shaped billet caster continuously cast in the fourth step needs to pay attention to the following three points:
firstly, the method comprises the following steps: a combined mode of a crystallizer and electromagnetic stirring at the tail end is adopted during casting, the target temperature is required to be controlled to 1450-1470 ℃, and the target pulling speed is required to be controlled to be 1.0-1.2 m/min;
II, secondly: the cooling control mode is that the secondary cooling area adopts a three-section type area water distribution mode, and the specific water quantity is automatically matched along with the pulling speed;
thirdly, the method comprises the following steps: cutting to length during blank discharging, and stacking in air cooling.
5. The preparation method of the EMS247 austenite valve steel bar for hot extrusion as claimed in claim 1, wherein the electroslag remelting in step five comprises the following specific steps:
a1: welding an electroslag base material blank and a false electrode, and carrying out electroslag remelting to obtain an electroslag steel ingot;
a2: after the electroslag steel ingot is demoulded, the electroslag steel ingot enters a sand pit for slow cooling within 15 minutes;
wherein, the electroslag remelting current is 5000-6000A, the voltage is 50-55V, and the remelting time is controlled to be 120-160 minutes; and (3) burying sand and slowly cooling the steel ingot, keeping the steel ingot slowly cooled to room temperature, taking the steel ingot out of a pit, and performing transition rolling.
6. The preparation method of the EMS247 austenite valve steel bar for hot extrusion, according to claim 1, wherein the heating apparatus for high-speed wire rolling in the sixth step is a pusher-type heating furnace or a walking beam type heating furnace, and the heating temperature of the bloom is controlled according to the following requirements: a preheating section: at most 920 ℃; a heating section: 920-1020 ℃, soaking section: 1130-1150 ℃; the initial rolling temperature: 1120-1140 ℃, the final rolling and spinning temperature is controlled to be more than or equal to 900 ℃, the finish rolling speed is controlled to be 28-35 m/s, air cooling is carried out, the steel wire enters a coil collecting line for collection, the steel wire is transferred to a heat treatment process, and the out-of-roundness of the hot rolled wire rod is controlled to be +/-0.15 mm.
7. The preparation method of the EMS247 austenite valve steel bar for hot extrusion, according to the claim 1, the annealing in the seventh step is that the 85Cr18Mo2V hot rolled wire rod is annealed within 6 hours, and the annealing is performed by using a trolley type electric furnace, the temperature is raised to room temperature to 850 ℃ along with the furnace, the temperature rise time is more than or equal to 4 hours, the temperature is kept for 4-4.5 hours when the temperature reaches 850 +/-10 ℃, and then the bar is cooled to below 600 ℃ along with the furnace and then cooled by air; straightening in the step eight, namely after the 85Cr18Mo2V hot-rolled wire rod is subjected to annealing heat treatment, soaking the 85Cr18Mo2V hot-rolled wire rod into a lime coating solution for a moment, pulling out, naturally drying, and straightening by a straightener on the basis of drying and whitening of a surface coating; and the step nine, polishing, inspection and warehousing means that the straightened 85Cr18Mo2V hot-rolled wire rod is subjected to grinding processing, centerless grinding is adopted for polishing, the steps are coarse grinding and fine grinding, NDT nondestructive inspection is carried out on the polished 85Cr18Mo2V hot-rolled wire rod, and the product is warehoused after being inspected to be qualified.
8. The preparation method of the EMS247 austenite valve steel hot extrusion bar according to claim 7, wherein in the step eight straightening, the straightener comprises a support table (1), a first transmission case (6) is arranged at the edge position of the left side of the upper end of the support table (1), an adjusting disc (5) is movably installed at the left end of the first transmission case (6), one end of the adjusting disc (5) is connected with a connecting rod (12), four groups of gears (11) are arranged on the connecting rod (12), a straightening case (8) and a second transmission case are arranged at the upper end of the support table (1) and on the right side of the first transmission case (6), and the second transmission case is arranged on the right side of the straightening case (8).
9. The preparation method of the EMS247 austenite valve steel hot extrusion bar according to claim 8, wherein the front end of the first transmission case (6) is provided with four sets of movable holes (21), two sets of limiting rods (10) are arranged in each movable hole (21), a movable plate (9) is movably installed in each movable hole (21), the front end of the movable plate (9) is provided with a second guide wheel (16), a first guide wheel (13) is arranged below the second guide wheel (16), one end of the first guide wheel (13) is connected with a transmission shaft (14), and the other end of the transmission shaft (14) is connected with a motor (15).
10. The preparation method of the EMS247 austenite valve steel hot extrusion bar according to claim 9, wherein two sets of limiting holes (17) are formed at the upper end of the movable plate (9), the limiting holes (17) are matched with the limiting rods (10), the rear end of the movable plate (9) is connected with a connecting plate (18), a plurality of sets of tooth sockets (19) are formed on the connecting plate (18), the tooth sockets (19) are meshed with the gears (11), the left end of the straightening box (8) is provided with an outlet (2), the right end of the straightening box (8) is provided with an inlet (20), a plurality of sets of horizontal wheels (3) are arranged at the left side of the interior of the straightening box (8), each set of horizontal wheels (3) is divided into an upper horizontal wheel and a lower horizontal wheel, a plurality of sets of vertical wheels (4) are arranged at the right side of the interior of the straightening box (8), and each set of vertical wheels (4) is divided into a front vertical wheel and a rear vertical wheel, and the vertical wheels (4) are arranged in a staggered way, and the horizontal wheels (3) and the vertical wheels (4) are movably arranged in the straightening box (8).
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| CN116100435A (en) * | 2023-03-19 | 2023-05-12 | 江苏江中集团有限公司 | Auxiliary polishing device for building construction |
| CN117358756A (en) * | 2023-09-26 | 2024-01-09 | 安徽富凯特材有限公司 | Rolling method for improving internal structure of ferronickel-chromium high-temperature corrosion-resistant alloy |
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Application publication date: 20210813 |