CN112899578A

CN112899578A - Bolt preparation process

Info

Publication number: CN112899578A
Application number: CN202110083387.1A
Authority: CN
Inventors: 牟昶宇
Original assignee: Individual
Current assignee: Individual
Priority date: 2021-01-21
Filing date: 2021-01-21
Publication date: 2021-06-04

Abstract

The invention discloses a bolt preparation process, which comprises the following steps: (1) preparing a rod blank through a casting process; (2) pickling the cast rod material; (3) heat treatment; (4) performing cryogenic treatment (5) on the heat-treated bolt, washing the bolt by using a 14% sodium hydroxide solution for degreasing treatment, and washing the bolt by using a 55% KHSO4 solution for pickling treatment; (6) blackening; the detachable supporting plate is adopted in the heat treatment stage, so that the bolts subjected to heat treatment can be conveniently taken into the cooling tank subjected to cryogenic treatment, and the bolts on the re-supporting plate can be completely poured into the cooling tank only by inclining, so that the method is convenient and rapid, and the working efficiency is improved.

Description

Bolt preparation process

Technical Field

The invention belongs to the technical field of bolt preparation, and particularly relates to a bolt preparation process.

Background

Need carry out heat treatment at the in-process of bolt preparation, need take the bolt to the degree of depth cooling after heat treatment has been good, but because high temperature, it is inconvenient to take the bolt to make work efficiency not high, so the heat treatment furnace must guarantee safety when taking moreover and will stop work, thereby reduced work efficiency.

Disclosure of Invention

The invention provides a bolt preparation process for improving preparation efficiency in order to overcome the defects of the prior art.

In order to achieve the purpose, the invention adopts the following technical scheme: a preparation process of a bolt comprises the following steps: (1) the rod blank is prepared by a casting process, and the weight percentage of each chemical component of the rod blank is controlled to meet the following requirements: 0.25-0.35% of C, 0.08-0.15% of Mn0.05-0.15% of Si, 0.01-0.04% of W, more than or equal to 0.015 and less than or equal to 0.025% of P, more than or equal to 0.015 and less than or equal to 0.035% of S, 0.15-0.20% of Ni, 0.025-0.045% of Zn0.02-0.03% of Sn, less than or equal to 0.02% of Cr and the balance of Fe; (2) pickling the cast rod material; drawing the wire according to the wire diameter requirement of the bolt so as to enable the rod material to be contracted to the wire diameter required by the bolt; cutting the rod material with the contracted wire diameter to the length required by the bolt, putting the cut rod material into a die cavity at normal temperature, and forming the rod material into the head and rod size required by the bolt by using upsetting force; turning the outer peripheral surface of the rod part by using a precision lathe to form threads, wherein a cutter on the lathe is a ceramic lathe tool, the working speed of the lathe tool is ensured to be 3300-; (3) heat treatment, namely putting the bolt into a vacuum heat treatment furnace, keeping the temperature for 1-2 hours when the temperature is raised to 450 +/-10 ℃ along with the furnace, keeping the temperature for 40-50 minutes when the temperature is raised to 700 +/-10 ℃ along with the furnace, keeping the temperature for 4-5 hours when the temperature is raised to 800 plus-minus-plus-minus 900 ℃ along with the furnace, then taking out of the furnace for quenching, putting the bolt into the furnace again after quenching, keeping the temperature for 6-8 hours when the temperature is raised to 550 plus-minus-plus-; (4) carrying out subzero treatment on the bolt after heat treatment, wherein the temperature of liquid nitrogen is-125 to-150 ℃, the time of subzero treatment is 2 to 5 hours, and the isothermal time in the liquid nitrogen is as follows: multiplying the cross-sectional area of the bolt by 2-3 min/mm2, and heating the bolt with the temperature returned to room temperature in 100 ℃ boiling water for 60-80 minutes after cryogenic treatment; (5) firstly, washing with 14% sodium hydroxide solution for degreasing treatment, controlling the temperature between 55 and 60 ℃ for 5 to 6 minutes, and then washing with water; washing with 55% KHSO4 solution at 18-20 deg.C for 1-2 min, and washing with water; finally, soaking the glass fiber into a sodium dodecyl benzene sulfonate solution at the temperature of 40 ℃, controlling the temperature to be 45-57 ℃, and soaking for 3 minutes, and then cleaning; (5) and (3) blackening, namely placing the bolt in a sodium nitrite solution at the temperature of 120-130 ℃ to treat the bolt until the surface of the bolt is black gray or completely black, taking the bolt out of the sodium nitrite solution, naturally curing for 15-20 min, fully cleaning with water, and air-drying to obtain a finished bolt.

Wherein the vacuum heat treatment furnace in the heat treatment step comprises a frame, a frame door arranged on the frame, a plurality of heating blocks distributed along the circumferential direction of the frame, a driving rod arranged on the frame, a plurality of annular driving grooves arranged on the frame, a plurality of longitudinal driving grooves arranged on the frame, a supporting frame slidably arranged on the longitudinal driving grooves, a first temperature groove arranged on the frame, a second temperature groove arranged on the frame, a third temperature groove arranged on the frame, a heat insulation plate for distinguishing the temperature grooves, and a sealing component arranged on the heat insulation plate;

opening a frame door, putting the support frame on which the bolts are placed into a first temperature groove through a longitudinal driving groove, wherein the temperatures of all areas of the temperature groove are different, and allowing the support frame to enter different temperature grooves through the longitudinal driving groove; the heat insulating board separates first temperature groove, second temperature groove and third temperature groove, like this, different temperature grooves have different temperatures, can let the bolt all can carry out work in the temperature of different stages, do not need the unified heating of wholesale, can keep lasting operating time, after the bolt hot working is good, open one of them frame door, two other temperature grooves still can keep work, thereby work efficiency has been improved, the carriage removes in annular driving groove and vertical driving groove, through vertical driving groove, can let the support frame get into different temperature grooves, through the annular driving groove, can let the carriage increase very much in same temperature groove, thereby improve hot working's bolt quantity, and then improve production efficiency.

The support frame also comprises a driving block which can slide on the longitudinal driving groove and the annular driving groove, an annular induction groove arranged on the driving rod, an induction block arranged on the driving block, an induction spring used for resetting the induction block, a first support block detachably arranged on the driving block, a pair of pliers used for disassembling the first support block, a support bar arranged on the driving block and used for supporting the first support block, a second support block slidably arranged on the first support block, a first limit component used for preventing a bolt from falling, a second limit component used for preventing the second support block from falling and a third limit component used for preventing the second support block from falling;

if a plurality of supporting frames are required to be arranged on the same temperature groove, the induction blocks of the supporting frames are moved to the annular induction groove, the driving blocks are just in the annular driving groove at the moment, then the supporting frames move along the annular driving groove and are circumferentially fixed in the temperature groove, so that the next supporting frame can enter the temperature groove, wherein the two sides of the annular induction groove are arc-shaped, so that the induction blocks can easily enter the annular induction groove, when the induction blocks enter the induction groove, the annular driving groove is started to enable the driving blocks to rotate around the driving rod anticlockwise or clockwise, in this way, redundant positions are left, a plurality of supporting frames can be placed into the temperature groove, as the supporting frames can rotate in the direction of the annular driving groove, when the supporting frames rotate, the bolts can also move, and pass through the first limiting assembly, the bolts can be placed on the supporting frames and cannot fall off, but also ensures the normal operation of hot working.

The first limiting assembly comprises a first limiting groove arranged on the first supporting block, a first limiting block slidably arranged on the first limiting groove, a first chamfer arranged on the first limiting block, a first limiting spring used for resetting the first limiting block, a groove arranged on the second supporting block, an L-shaped limiting block arranged on the second supporting block, and fixing grooves arranged on the first supporting block and the second supporting block; one end of the first limiting block with the chamfer can enter the second groove;

first stopper initial position lets first chamfer get into the recess, the second supporting shoe is blocked at its back, thereby make first supporting shoe block the second supporting shoe, when centre gripping second supporting shoe removes, first supporting shoe can be dismantled, put into the fixed slot the shank of bolt that needs heat treatment, the bolt head is on the fixed slot, below L type stopper, let the bolt spacing, like this, if want to put the bolt in the fixed slot, so only need hold the bolt, let the shank of bolt pass through first chamfer, promote first stopper and just can enter into the fixed slot, and when in the fixed slot, just can't go out, prevent that the carriage from letting the bolt fall down in the removal, finally guarantee the hot-working efficiency of bolt.

The second limiting assembly comprises a through groove arranged on the second supporting block, a lug arranged on the through groove and with one end connected with the first supporting block, an expanding opening arranged on the lug, and a second limiting spring arranged on the through groove and with two ends respectively connected with the lug and the second supporting block; the third limiting assembly comprises an empty groove arranged on the second supporting plate, a first opening arranged on the empty groove, a first push block arranged on the first opening in a sliding manner, second openings symmetrically arranged on the empty groove, a second push block arranged on the second opening in a sliding manner, a push part arranged on the second push block and a third limiting spring used for enabling the second push block to reset; two ends of the first opening are respectively connected with the empty groove and the groove; the first push block can push the second push block; the first push block can be fully keyed into the empty slot; one end of the second push block with the push part can come out of the second opening; the pushing part can be contacted with the first limiting block; the pliers comprise a fixed rod, an upper nipper capable of rotating around the fixed rod, a lower nipper capable of rotating around the fixed rod and a push rod slidably arranged on the fixed rod; the upper nipper and the lower nipper can clamp the second supporting block; the push rod can enter the groove and push the first limiting block; the push rod can enter the first opening and push the first push block.

After the bolt is subjected to heat treatment, the pliers grasp the second supporting block to enable the second supporting block and the first supporting block to be detached, the supporting frame is still in the original place, the first supporting block and the second supporting block with the bolt are taken above the cooling groove for deep cooling treatment, the push rod on the pliers is pushed, the push rod firstly enters the groove to push the first limiting block out of the groove, the second supporting block and the first supporting block slide relative to each other, then the push rod is pushed, the push rod enters the first opening to push the first push block, the first push block pushes the second push block, the push part on the second push block comes out of the second opening, then the first limiting block is inclined, the second limiting block slides out under the dead weight, the push part can be clamped by the first limiting block after sliding out for a certain distance, at the moment, the first supporting block does not slide, but the flaring is enlarged due to the previous sliding, and is inclined, can let the bolt that heat treatment has been good in the slot of reseing come out from the flaring, thereby fall the cooling bath, the slope down before, loosen the push rod now, then tilt up, can reset under the effect of first bracing piece and second spacing spring, on the one hand can let the portion of pushing away of second ejector pad contract to the dead slot through the third spacing spring, on the other hand is under the effect of first spacing spring, let the stopper have the one end of chamfer to enter into in the recess, thereby prevent the removal of second supporting shoe, then put new bolt on first supporting shoe and the second supporting shoe that has reset, put again and carry out heat treatment in the vacuum heating stove, high convenience and fastness, thereby improve work efficiency.

The sealing component comprises a sealing groove arranged on the heat insulation block, sealing blocks symmetrically arranged on the sealing groove, a rotating rod arranged on the heat insulation plate, and a pull rope of which two ends are respectively connected with the rotating rod and the sealing blocks; when the support frame has been heated in one of them heating tank for a period of time, when needing to enter into next heating tank, the bull stick rotates, the pulling stay cord, then sealed piece is opened to let the support frame get into next temperature groove, three temperature groove has two heat insulating boards, so next work can not be influenced in the time of one of them work, thereby only need a vacuum heating furnace just can have the temperature in a plurality of different regions to carry out hot working, thereby improve the work efficiency of bolt when hot processing.

In summary, the invention has the following advantages: through adopting the detachable backup pad in the thermal treatment stage, let by thermal treatment's bolt can conveniently take the cooling bath of subzero treatment, only need the slope in addition just can pour the bolt in the backup pad into the cooling bath again, convenient and fast improves work efficiency.

Drawings

FIG. 1 is a schematic structural diagram of the present invention.

Fig. 2 is a top view of the present invention.

Fig. 3 is a cross-sectional perspective view of fig. 2 taken along a-a.

Fig. 4 is a cross-sectional perspective view of fig. 2 taken along B-B.

Fig. 5 is a schematic structural view of the support frame of the present invention.

Fig. 6 is an exploded view of the support frame of the present invention.

Fig. 7 is a schematic structural view of the pliers of the present invention.

Fig. 8 is an enlarged view of a portion a in fig. 3.

Detailed Description

Example 1

A preparation process of a bolt comprises the following steps: the rod blank is prepared by a casting process, and the weight percentage of each chemical component of the rod blank is controlled to meet the following requirements: c: 0.25, Mn: 0.08, Si: 0.05, W: 0.01, P: 0.015, S: 0.015, Ni: 0.15, Zn: 0.025, Sn: 0.02, Cr: 0.01, and the balance being iron; (2) pickling the cast rod material; drawing the wire according to the wire diameter requirement of the bolt so as to enable the rod material to be contracted to the wire diameter required by the bolt; cutting the rod material with the contracted wire diameter to the length required by the bolt, putting the cut rod material into a die cavity at normal temperature, and forming the rod material into the head and rod size required by the bolt by using upsetting force; turning the outer peripheral surface of the rod part by using a precision lathe to form threads, wherein a cutter on the lathe is a ceramic lathe tool, the working speed of the lathe tool is guaranteed to be 3300r.p.m, feeding is started from one end opposite to the head part of the disc, and the cutting fluid is water-based cutting fluid; (3) heat treatment, putting the bolt into a vacuum heat treatment furnace, keeping the temperature for 1 hour when the temperature rises to 440 ℃ along with the furnace, keeping the temperature for 40 minutes when the temperature rises to 690 ℃ along with the furnace, keeping the temperature for 4 hours when the temperature rises to 800 ℃ along with the furnace, then taking out of the furnace for quenching, putting the bolt into the furnace again after quenching, keeping the temperature for 6 hours when the temperature rises to 550 ℃ along with the furnace, cooling the bolt by using aqueous quenching liquid after taking out of the furnace, putting the bolt into the furnace again after cooling, keeping the temperature for 5 hours when the temperature rises to 550 ℃ along with the furnace, and then taking out of; (4) carrying out subzero treatment on the bolt subjected to heat treatment, wherein the temperature of liquid nitrogen is-125 ℃, the time of subzero treatment is 2 hours, and the isothermal time in the liquid nitrogen is as follows: multiplying the cross-sectional area of the bolt by 2min/mm2, and heating the bolt with the temperature returned to room temperature in boiling water at 100 ℃ for 60 minutes after the cryogenic treatment; (5) firstly, washing with 14% sodium hydroxide solution for degreasing treatment, controlling the temperature to be 55 ℃ and the time to be 5 minutes, and then washing with water; washing with 55% KHSO4 solution at 18 deg.C for 1 min, and washing with water; finally, soaking the glass fiber into a sodium dodecyl benzene sulfonate solution at the temperature of 40 ℃, controlling the temperature at 45 ℃, and soaking for 3 minutes, and then cleaning; (6) and (3) blackening, namely, putting the bolt into a sodium nitrite solution at the temperature of 120 ℃ to be treated until the surface of the bolt is black gray or completely black, taking the bolt out of the sodium nitrite solution, naturally curing for 15min, fully cleaning with water, and air-drying to obtain a finished bolt.

As shown in fig. 1 to 8, the vacuum heat treatment furnace includes a frame 1, a door of the frame 1, a plurality of heating blocks 12, a driving rod 13, a plurality of annular driving grooves 14, a plurality of longitudinal driving grooves 15, a supporting frame 2, a first temperature groove 16, a second temperature groove 17, a third temperature groove 18, a heat insulating plate 19, and a sealing member 6; a frame 1 is arranged on the frame 1, a plurality of heating blocks 12 are distributed along the circumferential direction of the frame 1, a driving rod 13 is arranged on the frame 1, a plurality of annular driving grooves 14 are arranged on the frame 1, a plurality of longitudinal driving grooves 15 are arranged on the frame 1, a supporting frame 2 is slidably arranged on the longitudinal driving grooves 15, a first temperature groove 16 is arranged on the frame 1, a second temperature groove 17 is arranged on the frame 1, a third temperature groove 18 is arranged on the frame 1, a heat insulation plate 19 is used for distinguishing each temperature groove, and a sealing part 6 is arranged on the heat insulation plate 19; the frame 1 door is opened, the support frame 2 with the bolts is placed into the first temperature groove 16 through the longitudinal driving groove 15, the temperature of each area of the temperature groove is different, and the support frame 2 enters the different temperature grooves through the longitudinal driving groove 15.

As shown in fig. 3, 5 and 6, the supporting frame 2 further includes a driving block 21, an annular sensing groove 22, a sensing block 23, a sensing spring 24, a first supporting block 25, a pair of pliers 7, a supporting bar 26, a second supporting block 27, a first limiting component 3, a second limiting component 4 and a third limiting component 5; the driving block 21 can slide on the longitudinal driving groove 15 and the annular driving groove 14, the annular sensing groove 22 is arranged on the driving rod 13, the sensing block 23 is arranged on the driving block 21, the sensing spring 24 is used for resetting the sensing block 23, the first supporting block 25 is detachably arranged on the driving block 21, the pliers 7 is used for detaching the first supporting block 25, the supporting bar 26 is arranged on the driving block 21 and is used for supporting the first supporting block 25, the second supporting block 27 is slidably arranged on the first supporting block 25, the first limiting component 3 is used for preventing a bolt from falling off, the second limiting component 4 is used for preventing the second supporting block 27 from falling off, and the third limiting component 5 is used for preventing the second supporting block 27 from falling off; if a plurality of support frames 2 are required to be positioned on the same temperature groove, the induction block 23 of each support frame 2 moves to the annular induction groove 22, the driving block 21 is right positioned in the annular driving groove 14 at the moment, and then the support frames 2 move along the annular driving groove 14 and are circumferentially fixed in the temperature groove, so that the next support frame 2 can enter the temperature groove.

As shown in fig. 5, the first limiting component 3 includes a first limiting groove 31, a first limiting block 32, a first chamfer 33, a first limiting spring 34, a groove 35, an L-shaped limiting block 36, and a fixing groove 37; a first limiting groove 31 is formed in the first supporting block 25, a first limiting block 32 is slidably arranged in the first limiting groove 31, a first chamfer 33 is formed in the first limiting block 32, a first limiting spring 34 is used for resetting the first limiting block 32, a groove 35 is formed in the second supporting block 27, an L-shaped limiting block 36 is formed in the second supporting block 27, and a fixing groove 37 is formed in the first supporting block 25 and the second supporting block 27; the chamfered end of the first stopper 32 can enter the second groove 35; the initial position of the first stopper 32 is to let the first chamfer 33 enter the groove 35, and the back of the first chamfer is clamped with the second supporting block 27, so that the first supporting block 25 is clamped with the second supporting block 27, when the second supporting block 27 is clamped to move, the first supporting block 25 can be disassembled, a bolt rod to be heat-treated is put into the fixing groove 37, the bolt head is arranged above the fixing groove 37, and the bolt is limited under the L-shaped stopper 36.

As shown in fig. 8, the second limiting assembly 4 comprises a through slot 41, a bump 42, a flared opening 43, and a second limiting spring 44; a through groove 41 is arranged on the second supporting block 27, a lug 42 is arranged on the through groove 41, one end of the lug is connected with the first supporting block 25, a flared opening 43 is arranged on the lug 42, a second limiting spring 44 is arranged on the through groove 41, and two ends of the second limiting spring are respectively connected with the lug 42 and the second supporting block 27; by pulling on the second support block 27, the flared end 43 may be enlarged and the heat treated bolt may be removed from the flared end 43.

As shown in fig. 6 and 8, the third limiting component 5 includes a hollow slot 51, a first opening 52, a first pushing block 53, a second opening 54, a second pushing block 55, a pushing part 56, and a third limiting spring 57; the hollow groove 51 is arranged on the second support plate, the first opening 52 is arranged on the hollow groove 51, the first push block 53 is slidably arranged on the first opening 52, the second openings 54 are symmetrically arranged on the hollow groove 51, the second push block 55 is slidably arranged on the second opening 54, the push part 56 is arranged on the second push block 55, and the third limiting spring 57 is used for resetting the second push block 55; two ends of the first opening 52 are respectively connected with the empty groove 51 and the groove 35; the first pushing block 53 can push the second pushing block 55; the first push block 53 can be keyed entirely into the empty slot 51; one end of the second pushing block 55 having a pushing part 56 can come out from the second opening 54; the pushing part 56 can contact with the first stopper 32; the first pushing block 53 is pushed, and the second pushing block 55 moves to both sides, so that the pushing part 56 comes out of the second opening 54.

As shown in fig. 4, the sealing member 6 includes a sealing groove 61, a sealing block 62, a rotating rod 63, and a pulling rope 64; the sealing groove 61 is arranged on the heat insulation block, the sealing blocks 62 are symmetrically arranged on the sealing groove 61, the rotating rod 63 is arranged on the heat insulation plate 19, and two ends of the pull rope 64 are respectively connected with the rotating rod 63 and the sealing blocks 62; when support frame 2 will get into next temperature groove, bull stick 63 rotates, and pulling rope 64 lets sealed piece 62 open to let support frame 2 get into next temperature groove.

As shown in fig. 7, the forceps 7 includes a fixing rod 71, an upper nipper 72, a lower nipper 73, and a push rod 74; the upper nipper 72 can rotate around the fixed rod 71, the lower nipper 73 can rotate around the fixed rod 71, and the push rod 74 can be slidably arranged on the fixed rod 71; the upper nipper 72 and the lower nipper 73 can nip the second supporting block 27; the push rod 74 can enter the groove 35 and push the first stopper 32; the push rod 74 can enter the first opening 52 and push the first push block 53; after the bolts are heat-treated, the pliers 7 grasps the second supporting block 27, the second supporting block 27 and the first supporting block 25 are detached, the bolts are placed above the cooling groove for cryogenic treatment, the push rod 74 is pushed, the push rod 74 enters the groove 35 to push the first stopper 32 out of the groove 35, so that the second supporting block 27 and the first supporting block 25 slide relative to each other, then the push rod 74 is pushed again, the push rod 74 enters the first opening 52 to push the first push block 53, the first push block 53 pushes the second push block 55, the push part 56 on the second push block 55 comes out of the second opening 54, then the first stopper 32 is inclined, the second stopper slides out under self-weight, the push part 56 is clamped by the first stopper 32 after sliding out for a certain distance, at the moment, the first supporting block 25 does not slide, but the flaring 43 is enlarged due to the previous sliding, and the inclined, so that the bolts in the groove 37 which are heat-treated come out of the flaring 43, and thus falls into the cooling bath.

Example 2

A preparation process of a bolt comprises the following steps: the rod blank is prepared by a casting process, and the weight percentage of each chemical component of the rod blank is controlled to meet the following requirements: c: 0.35, Mn: 0.15, Si: 0.15, W: 0.04, P: 0.025, S: 0.035, Ni: 0.20, Zn: 0.045, Sn: 0.03, Cr: 0.02, and the balance being iron; (2) pickling the cast rod material; drawing the wire according to the wire diameter requirement of the bolt so as to enable the rod material to be contracted to the wire diameter required by the bolt; cutting the rod material with the contracted wire diameter to the length required by the bolt, putting the cut rod material into a die cavity at normal temperature, and forming the rod material into the head and rod size required by the bolt by using upsetting force; turning the outer peripheral surface of the rod part by using a precision lathe to form threads, wherein a cutter on the lathe is a ceramic lathe tool, the working speed of the lathe tool is guaranteed to be 3500r.p.m, feeding is started from one end opposite to the head part of the disc, and the cutting fluid is water-based cutting fluid; (3) heat treatment, putting the bolt into a vacuum heat treatment furnace, keeping the temperature for 2 hours when the temperature rises to 460 ℃ along with the furnace, keeping the temperature for 50 minutes when the temperature rises to 710 ℃ along with the furnace, keeping the temperature for 5 hours when the temperature rises to 900 ℃ along with the furnace, then taking out of the furnace for quenching, putting the bolt into the furnace again after quenching, keeping the temperature for 8 hours when the temperature rises to 650 ℃ along with the furnace, cooling the bolt by using aqueous quenching liquid after taking out of the furnace, putting the bolt into the furnace again after cooling, keeping the temperature for 6 hours when the temperature rises to 650 ℃ along with the furnace, and then taking out of; (4) carrying out subzero treatment on the bolt subjected to heat treatment, wherein the temperature of liquid nitrogen is-150 ℃, the time of subzero treatment is 5 hours, and the isothermal time in the liquid nitrogen is as follows: multiplying the cross-sectional area of the bolt by 3min/mm2, and heating the bolt with the temperature returned to room temperature in boiling water at 100 ℃ for 80 minutes after the cryogenic treatment; (5) firstly, washing with 14% sodium hydroxide solution for degreasing treatment, controlling the temperature between 60 ℃ for 6 minutes, and then washing with water; washing with 55% KHSO4 solution at 20 deg.C for 2min, and washing with water; finally, soaking the glass fiber into a sodium dodecyl benzene sulfonate solution at the temperature of 40 ℃, controlling the temperature at 57 ℃, and soaking for 3 minutes, and then cleaning; (6) and (3) blackening, namely, placing the bolt in a sodium nitrite solution at the temperature of 130 ℃ to treat the bolt until the surface of the bolt is black gray or completely black, taking the bolt out of the sodium nitrite solution, naturally curing for 20min, fully cleaning with water, and air-drying to obtain a finished bolt.

Example 3

A preparation process of a bolt comprises the following steps: the rod blank is prepared by a casting process, and the weight percentage of each chemical component of the rod blank is controlled to meet the following requirements: c: 0.3, Mn: 0.1, Si: 0.1, W: 0.25, P: 0.02, S: 0.02, Ni: 0.17, Zn: 0.03, Sn: 0.025, Cr: 0.015 percent, and the balance of iron; (2) pickling the cast rod material; drawing the wire according to the wire diameter requirement of the bolt so as to enable the rod material to be contracted to the wire diameter required by the bolt; cutting the rod material with the contracted wire diameter to the length required by the bolt, putting the cut rod material into a die cavity at normal temperature, and forming the rod material into the head and rod size required by the bolt by using upsetting force; turning the outer peripheral surface of the rod part by using a precision lathe to form threads, wherein a cutter on the lathe is a ceramic lathe tool, the working speed of the lathe tool is ensured to be 3400r.p.m, feeding is started from one end opposite to the head part of the disc, and the cutting fluid is water-based cutting fluid; (3) heat treatment, putting the bolt into a vacuum heat treatment furnace, keeping the temperature for 1.5 hours when the temperature rises to 460 ℃ along with the furnace, keeping the temperature for 45 minutes when the temperature rises to 710 ℃ along with the furnace, keeping the temperature for 4.5 hours when the temperature rises to 850 ℃ along with the furnace, then taking out of the furnace for quenching, putting the bolt into the furnace again after quenching, keeping the temperature for 7 hours when the temperature rises to 600 ℃ along with the furnace, cooling the bolt by using aqueous quenching liquid, putting the bolt into the furnace again after cooling, keeping the temperature for 5.5 hours when the temperature rises to 600 ℃ along with the furnace, and then taking out of the furnace for water cooling; (4) carrying out subzero treatment on the bolt subjected to heat treatment, wherein the temperature of liquid nitrogen is-135 ℃, the time of subzero treatment is 3.5 hours, and the isothermal time in the liquid nitrogen is as follows: multiplying the cross-sectional area of the bolt by 2.5min/mm2, and heating the bolt with the temperature returned to room temperature in boiling water at 100 ℃ for 70 minutes after the cryogenic treatment; (5) firstly, washing with 14% sodium hydroxide solution for degreasing treatment, controlling the temperature to be 57.5 ℃ and the time to be 5.5 minutes, and then washing with water; washing with 55% KHSO4 solution at 19 deg.C for 1.5 min, and washing with water; finally, soaking the glass fiber into a sodium dodecyl benzene sulfonate solution at the temperature of 40 ℃, controlling the temperature at 50 ℃, and soaking for 3 minutes, and then cleaning; (6) and (3) blackening, namely, placing the bolt in a sodium nitrite solution at the temperature of 125 ℃ to treat the bolt until the surface of the bolt is black gray or completely black, taking the bolt out of the sodium nitrite solution, naturally curing for 17min, fully cleaning with water, and air-drying to obtain a finished bolt.

Claims

1. A preparation process of a bolt is characterized by comprising the following steps: the method comprises the following steps:

(1) the rod blank is prepared by a casting process, and the weight percentage of each chemical component of the rod blank is controlled to meet the following requirements: 0.25-0.35% of C, 0.08-0.15% of Mn0.05-0.15% of Si, 0.01-0.04% of W, more than or equal to 0.015 and less than or equal to 0.025% of P, more than or equal to 0.015 and less than or equal to 0.035% of S, 0.15-0.20% of Ni, 0.025-0.045% of Zn0.02-0.03% of Sn, less than or equal to 0.02% of Cr and the balance of Fe;

(2) pickling the cast rod material; drawing the wire according to the wire diameter requirement of the bolt so as to enable the rod material to be contracted to the wire diameter required by the bolt; cutting the rod material with the contracted wire diameter to the length required by the bolt, putting the cut rod material into a die cavity at normal temperature, and forming the rod material into the head and rod size required by the bolt by using upsetting force; turning the outer peripheral surface of the rod part by using a precision lathe to form threads, wherein a cutter on the lathe is a ceramic lathe tool, the working speed of the lathe tool is ensured to be 3300-;

(3) heat treatment, namely putting the bolt into a vacuum heat treatment furnace, keeping the temperature for 1-2 hours when the temperature is raised to 450 +/-10 ℃ along with the furnace, keeping the temperature for 40-50 minutes when the temperature is raised to 700 +/-10 ℃ along with the furnace, keeping the temperature for 4-5 hours when the temperature is raised to 800 plus-minus-plus-minus 900 ℃ along with the furnace, then taking out of the furnace for quenching, putting the bolt into the furnace again after quenching, keeping the temperature for 6-8 hours when the temperature is raised to 550 plus-minus-plus-;

(4) carrying out subzero treatment on the bolt after heat treatment, wherein the temperature of liquid nitrogen is-125 to-150 ℃, the time of subzero treatment is 2 to 5 hours, and the isothermal time in the liquid nitrogen is as follows: multiplying the cross-sectional area of the bolt by 2-3 min/mm2, and heating the bolt with the temperature returned to room temperature in 100 ℃ boiling water for 60-80 minutes after cryogenic treatment;

(5) firstly, washing with 14% sodium hydroxide solution for degreasing treatment, controlling the temperature between 55 and 60 ℃ for 5 to 6 minutes, and then washing with water; washing with 55% KHSO4 solution at 18-20 deg.C for 1-2 min, and washing with water; finally, soaking the glass fiber into a sodium dodecyl benzene sulfonate solution at the temperature of 40 ℃, controlling the temperature to be 45-57 ℃, and soaking for 3 minutes, and then cleaning;

(6) and (3) blackening, namely placing the bolt in a sodium nitrite solution at the temperature of 120-130 ℃ to treat the bolt until the surface of the bolt is black gray or completely black, taking the bolt out of the sodium nitrite solution, naturally curing for 15-20 min, fully cleaning with water, and air-drying to obtain a finished bolt.

The vacuum heat treatment furnace in the heat treatment step comprises a frame (1), a frame (1) door arranged on the frame (1), a plurality of heating blocks (12) distributed along the circumferential direction of the frame (1), a driving rod (13) arranged on the frame (1), a plurality of annular driving grooves (14) arranged on the frame (1), a plurality of longitudinal driving grooves (15) arranged on the frame (1), a supporting frame (2) arranged on the longitudinal driving grooves (15) in a sliding manner, a first temperature groove (16) arranged on the frame (1), a second temperature groove (17) arranged on the frame (1), a third temperature groove (18) arranged on the frame (1), heat insulation plates (19) used for distinguishing the temperature grooves, and sealing components (6) arranged on the heat insulation plates (19); the door of the frame (1) is opened, the support frame (2) on which the bolts are placed is placed into a first temperature groove (16) through a longitudinal driving groove (15), the temperatures of all areas of the temperature groove are different, and the support frame (2) enters different temperature grooves through the longitudinal driving groove (15).

2. The process for producing a bolt according to claim 1, wherein: support frame (2) still include both can slide on vertical drive groove (15) and can be in gliding drive block (21) on annular drive groove (14), locate annular response groove (22) on actuating lever (13), locate response piece (23) on drive block (21), be used for letting response spring (24) that response piece (23) reset, detachably locate first supporting block (25) on drive block (21), be used for dismantling pliers (7) of first supporting block (25), locate on drive block (21) and be used for supporting support bar (26) of first supporting block (25), locate slidable second supporting block (27) on first supporting block (25), be used for preventing first spacing subassembly (3) that the bolt dropped, be used for preventing second spacing subassembly (4) that second supporting block (27) dropped, A third limiting component (5) for preventing the second supporting block (27) from falling; if a plurality of support frames (2) are required to be arranged on the same temperature groove, the induction block (23) of each support frame (2) moves to the annular induction groove (22), the driving block (21) is just in the annular driving groove (14), then the support frames (2) move along the annular driving groove (14) and are circumferentially fixed in the temperature groove, and the next support frame (2) can enter the temperature groove.

3. The process for producing a bolt according to claim 2, wherein: the first limiting assembly (3) comprises a first limiting groove (31) arranged on the first supporting block (25), a first limiting block (32) slidably arranged on the first limiting groove (31), a first chamfer (33) arranged on the first limiting block (32), a first limiting spring (34) for resetting the first limiting block (32), a groove (35) arranged on the second supporting block (27), an L-shaped limiting block (36) arranged on the second supporting block (27), and fixing grooves (37) arranged on the first supporting block (25) and the second supporting block (27); one end of the first limiting block (32) with the chamfer angle can enter the second groove (35); the initial position of the first limiting block (32) is that the first chamfer (33) enters the groove (35), the back of the first limiting block clamps the second supporting block (27), so that the first supporting block (25) clamps the second supporting block (27), when the second supporting block (27) is clamped to move, the first supporting block (25) can be detached, a bolt rod needing heat treatment is placed into the fixing groove (37), the bolt head is arranged on the fixing groove (37), and the bolt is limited below the L-shaped limiting block (36).

4. The process for producing a bolt according to claim 3, wherein: the second limiting component (4) comprises a through groove (41) arranged on the second supporting block (27), a lug (42) arranged on the through groove (41) and one end of the lug is connected with the first supporting block (25), a flared opening (43) arranged on the lug (42), and a second limiting spring (44) arranged on the through groove (41) and two ends of the second limiting spring are respectively connected with the lug (42) and the second supporting block (27); by pulling the second support block (27), the flare (43) may be enlarged and the heat treated bolt may be removed from the flare (43).

5. The process for producing a bolt according to claim 4, wherein: the third limiting assembly (5) comprises an empty groove (51) arranged on the second supporting plate, a first opening (52) arranged on the empty groove (51), a first push block (53) slidably arranged on the first opening (52), second openings (54) symmetrically arranged on the empty groove (51), a second push block (55) slidably arranged on the second opening (54), a push part (56) arranged on the second push block (55), and a third limiting spring (57) for resetting the second push block (55); two ends of the first opening (52) are respectively connected with the empty groove (51) and the groove (35); the first pushing block (53) can push the second pushing block (55); the first push block (53) can be keyed entirely into the empty slot (51); one end of the second push block (55) with a push part (56) can come out of the second opening (54); the pushing part (56) can be contacted with the first limiting block (32); the first pushing block (53) is pushed, the second pushing block (55) moves towards two sides, and the pushing part (56) comes out of the second opening (54).

6. The process for producing a bolt according to claim 5, wherein: the sealing component (6) comprises a sealing groove (61) arranged on the heat insulation block, sealing blocks (62) symmetrically arranged on the sealing groove (61), a rotating rod (63) arranged on the heat insulation plate (19), and a pull rope (64) with two ends respectively connected with the rotating rod (63) and the sealing blocks (62); when support frame (2) will get into next temperature groove, bull stick (63) rotate, stimulate stay cord (64), let sealed piece (62) open to let support frame (2) get into next temperature groove.

7. The process for producing a bolt according to claim 6, wherein: the pliers (7) comprises a fixed rod (71), an upper nipper (72) capable of rotating around the fixed rod (71), a lower nipper (73) capable of rotating around the fixed rod (71), and a push rod (74) slidably arranged on the fixed rod (71); the upper nipper (72) and the lower nipper (73) can clamp the second supporting block (27); the push rod (74) can enter the groove (35) and push the first limiting block (32); the push rod (74) can enter the first opening (52) and push the first push block (53); after the bolt is subjected to heat treatment, a pliers (7) grasps the second supporting block (27), the second supporting block (27) and the first supporting block (25) are detached, the second supporting block (27) and the first supporting block (25) are placed above a cooling groove subjected to deep cooling treatment, a push rod (74) is pushed, the push rod (74) enters the groove (35) to push the first limiting block (32) out of the groove (35), the second supporting block (27) and the first supporting block (25) slide relatively, then the push rod (74) is pushed, the push rod (74) enters the first opening (52) to push the first pushing block (53), the first pushing block (53) pushes the second pushing block (55), a pushing part (56) on the second pushing block (55) comes out of the second opening (54), then the first limiting block (32) is inclined, the second limiting block slides out under the self weight, and after the second limiting block slides out for a distance, the pushing part (56) can be clamped by the first limiting block (32), at this time, the first support block (25) does not slide, but the flare (43) becomes large due to the previous sliding, and the bolts in the re-fixing groove (37) that have been heat-treated come out of the flare (43) due to the inclination, and fall into the cooling groove.