A guide device for a piercer for producing thin-walled seamless steel pipes

Abstract

The present application belongs to the technical field of thin-walled steel pipe, and provides a guide plate device for producing thin-walled seamless steel pipe and a piercing mill. The guide plate device comprises two guide plates, the two guide plates are oppositely and spacedly arranged for the pipe blank to pass through, the two guide plates are fixedly installed on corresponding guide plate seats, at least one guide plate seat is connected with an adjusting mechanism, and the spacing between the two guide plates is adjusted through the adjusting mechanism. Through the adjusting mechanism arranged on the guide plate seat, the present application can freely adjust the spacing between the guide plates, so as to meet the use requirements of different models of seamless steel pipes, improve the utilization rate of the equipment, and save the production cost.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of thin-walled steel pipes, and particularly relates to a guide plate device for producing thin-walled seamless steel pipes and a piercing mill. BACKGROUND

[0002] In a seamless steel pipe production unit, a three-roll pipe mill is more suitable for the production of medium-thick-walled steel pipes, but sometimes users need different specifications of whole orders for delivery, which involves the production of thin-walled steel pipes. Therefore, the stability of production quality needs to be guaranteed. According to the normal control method, the wall thickness uniformity of thick-walled pipes can be effectively guaranteed, but when producing thin-walled pipes with a wall thickness of less than 25 mm, the problem of wall thickness eccentricity often occurs. The eccentricity is often hidden, the wall thickness deviation of the head part is qualified, and the wall thickness deviation of the middle part and the tail part is out of tolerance, resulting in that the produced steel pipe does not meet the technical agreement standard requirements, and the steel pipe is scrapped.

[0003] As shown in Figure 1 , the uneven wall thickness of the steel pipe refers to the absolute difference between the thickest point and the thinnest point of the wall thickness of the steel pipe on the same section or in the length direction, which exceeds the positive deviation or the negative deviation.

[0004] The existing piercing mill for producing thin-walled seamless steel pipes has fixed guide plate spacing, which is not conducive to the production of various types of seamless steel pipes, and the versatility of the piercing mill is not strong.

[0005] In the process of producing thin-walled pipes, the piercing mill has the characteristics of large deformation, large ovality and large diameter expansion. In the actual production process, the use of the guide plate is tracked, and the local nodule at the outlet of the guide plate leads to scratches on the hot surface of the steel pipe during the piercing process. In severe cases, the steel pipe surface is peeled off. The scratches on the surface of the steel pipe are distributed in a spiral shape. When the pipe surface is peeled off, it can be found during manual inspection, and the depth is 0.8-1.5 mm. However, the spiral marks without peeling are pressed inside during the subsequent rolling process, and the surface of the finished pipe cannot be found by visual inspection, and only magnetic particle inspection can be found. The measured indentation depth is 0.2-0.5 mm.

[0006] Therefore, it is necessary to provide an improved technical solution for the above-mentioned deficiencies of the prior art. SUMMARY

[0007] The purpose of the present application is to provide a piercing mill for producing thin-walled seamless steel pipes, which can solve the deficiencies in the prior art. The present application also provides a guide plate device of a piercing mill.

[0008] In order to achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0009] A guide plate device for producing thin-walled seamless steel pipes, the guide plate device comprising guide plates, the guide plates being two, the two guide plates being oppositely spaced apart for a pipe blank to pass through, the two guide plates being fixedly installed on corresponding guide plate seats, at least one of the guide plate seats being connected with an adjusting mechanism, the spacing between the two guide plates being adjusted by the adjusting mechanism.

[0010] The guide plate device for producing thin-walled seamless steel pipes as described above, preferably, the guide plates are fixedly connected to the guide plate seats in a detachable manner, so as to replace the guide plates according to the wall thickness of the pipe blank.

[0011] The guide plate device for producing thin-walled seamless steel pipes as described above, preferably, the guide plate seats are installed on a track, the adjusting mechanism comprises a hydraulic swing cylinder, the hydraulic swing cylinder is arranged below the track, an output shaft of the hydraulic swing cylinder is connected with one end of a swing rod, the other end of the swing rod is provided with a mounting hole, a horizontal rod is inserted into the mounting hole, both ends of the horizontal rod are provided with inclined rods, the lower end of each of the inclined rods is fixedly connected with the horizontal rod, the upper end of each of the inclined rods is hingedly connected with a mounting frame, the mounting frame is fixedly connected with the guide plate seat;

[0012] The swing rod is driven to rotate by the hydraulic swing cylinder, so as to drive the guide plate seat to move linearly along the track through the inclined rods.

[0013] The guide plate device for producing thin-walled seamless steel pipes as described above, preferably, a worm gear device is arranged outside the track and close to the guide plates,

[0014] The worm gear device comprises a worm wheel and a worm, a main shaft of a motor is drivingly connected with the worm, the worm is drivingly connected with the worm wheel, the worm wheel is drivingly connected with a lead screw, the lead screw is arranged in parallel with the track;

[0015] The worm is driven to rotate by the rotation of the main shaft of the motor, the worm drives the worm wheel to rotate, the worm wheel drives the lead screw to move linearly along the track, so that the lead screw and the mounting frame are in abutting engagement in the direction of the track.

[0016] The guide plate device for producing thin-walled seamless steel pipes as described above, preferably, the spacing between the two guide plates is a guide plate distance,

[0017] When producing a pipe blank with a diameter of 270 mm and a wall thickness of 25 mm or less, the guide plate distance is 270 mm or less;

[0018] When producing a pipe blank with a diameter of 330 mm and a wall thickness of 25 mm or less, the guide plate distance is 330 mm or less.

[0019] The guide plate device for producing thin-walled seamless steel pipes as described above is preferably, when producing a ∮270mm blank and a steel pipe with a wall thickness of 25mm or less, the width of the guide plate is 225-250cm.

[0020] When producing a ∮330mm blank and a steel pipe with a wall thickness of 25mm or less, the width of the guide plate is 275-290cm.

[0021] The guide plate device for producing thin-walled seamless steel pipes as described above is preferably, the guide plate comprises an inlet cone and an outlet cone, the taper angle of the inlet cone is 2-4°, and the taper angle of the outlet cone is 2.5-4°.

[0022] The guide plate device for producing thin-walled seamless steel pipes as described above is preferably, the surface of the guide plate is provided with a surface strengthening layer, and the surface strengthening layer is any one of a laser cladding layer, an argon arc cladding layer, a surface overlaying layer or an electroplating layer.

[0023] The material of the surface strengthening layer is a particle reinforced metal matrix composite, the particle reinforcement of the particle reinforced metal matrix composite is ceramic, and the ceramic is one or more of carbide, oxide, boride and nitride; and the base material of the particle reinforced metal matrix composite is one or more of titanium, iron-aluminum alloy, iron, magnesium and nickel.

[0024] The guide plate device for producing thin-walled seamless steel pipes as described above is preferably, the surface strengthening layer is located on the surface of the outlet cone of the guide plate; and the surface strengthening layer is a laser cladding layer.

[0025] The particle reinforcement is an in-situ self-grown particle reinforcement, and the in-situ self-grown particle reinforcement is a composite carbide.

[0026] A piercing mill for producing thin-walled seamless steel pipes, the piercing mill comprises any one of the guide plate devices as described above, and the piercing mill further comprises a rolling roller, the rolling roller comprises an upper roller and a lower roller, and the upper roller, the lower roller and the guide plate device enclose a piercing area for the pipe blank to pass through.

[0027] Beneficial effects: the adjusting mechanism is arranged on the guide plate seat, the distance between the guide plates can be freely adjusted to meet the use requirements of different models of seamless steel pipes, the utilization rate of the equipment is improved, and the production cost is saved.

[0028] The deformation amount is large when the thin-walled pipe is pierced, the self-metal binding force is poor, and the thin-walled pipe is more easily deformed in the transverse direction during piercing. The guide plate plays a limiting role in maintaining the piercing center line, the smaller guide plate distance is adopted during the production of the thin-walled pipe, the shaking of the piercing head in the rolling roller of the piercing mill is limited, so that the piercing head is stable during the piercing deformation, and the eccentricity of the thin-walled steel pipe can be effectively avoided. BRIEF DESCRIPTION OF DRAWINGS

[0029] The accompanying drawings, which form a part of this specification, are included to provide a further understanding of the application, and are incorporated into and constitute a part of the specification. To the extent that the drawings illustrate embodiments of the present application and describe the

[0030] Figure 1 A schematic view of the structure of the uneven wall thickness of the steel pipe in the prior art;

[0031] Figure 2 A schematic view of the structure of the piercing mill in the present application;

[0032] Figure 3 A schematic view of the structure of the guide plate in the present application;

[0033] Figure 4 A schematic view of the structure of the guide plate device in the present application.

[0034] Corresponding names of various reference numerals in the drawings are as follows: 1 - upper roller; 2 - lower roller; 3 - guide plate; 4 - inlet cone; 5 - outlet cone; 6 - rolling line; 7 - hoisting screw hole; 8 - guide plate seat; 9 - track; 10 - hydraulic swing oil cylinder; 11 - swing rod; 12 - horizontal rod; 13 - inclined rod; 14 - mounting frame; 15 - worm and gear device; 16 - screw rod. DETAILED DESCRIPTION

[0035] The technical solutions in the embodiments of the present application will be described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments in the present application belong to the scope of protection of the present application.

[0036] In the description of the present application, the orientations or positional relationships indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", and the like are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present application, and are not required to be the specific orientations and operations of the present application, and therefore cannot be understood as limitations on the present application. The terms "connected", "connected" used in the present application should be understood broadly, for example, can be fixed connection, can also be detachable connection; can be directly connected, can also be indirectly connected through intermediate components. For those skilled in the art, the specific meanings of the above terms can be understood according to the specific circumstances.

[0037] The present application will be described in detail below with reference to the drawings and in combination with the embodiments. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0038] Embodiment of the guide plate 3 device for producing thin-walled seamless steel pipe in the present application:

[0039] As Figures 2-4 shown, a guide plate device for producing thin-walled seamless steel pipe, the guide plate device comprises two guide plates 3, the two guide plates 3 are oppositely spaced for pipe blank to pass through, the two guide plates are fixedly installed on corresponding guide plate seats, at least one guide plate seat is connected with an adjusting mechanism, the spacing between the two guide plates is adjusted through the adjusting mechanism, and the spacing between the two guide plates 3 is a guide plate distance. The two guide plates 3 are a left guide plate and a right guide plate respectively.

[0040] In the application, since the guide plate 3 is arranged on the guide plate seat 8, the spacing between the two guide plate seats can be freely adjusted through the adjusting mechanism arranged on one or two guide plate seats 8, and then the adjustment of the spacing between the two guide plates can be realized, so that the application meets the use requirements of different models of seamless steel pipes, improves the equipment utilization rate, and saves the production cost.

[0041] In an optional embodiment of the application, the guide plate 3 is fixedly connected to the guide plate seat 8 in a detachable manner, so as to replace the guide plate according to the wall thickness of the pipe blank. Specifically, the guide plate 3 is fastened to the guide plate seat 8 through a tensioning device.

[0042] In an optional embodiment of the application, the guide plate seat 8 is installed on the track 9, the adjusting mechanism comprises a hydraulic swing oil cylinder 10, the hydraulic swing oil cylinder 10 is arranged below the track 9, an output shaft of the hydraulic swing oil cylinder 10 is connected to one end of a swing rod 11, the other end of the swing rod 11 is provided with a mounting hole, a horizontal rod 12 is inserted into the mounting hole, both ends of the horizontal rod 12 are provided with inclined rods 13, the lower end of the inclined rod 13 is fixedly connected to the horizontal rod, the upper end of the inclined rod 13 is hingedly connected to a mounting frame 14, and the mounting frame 14 is fixedly connected to the guide plate seat 8; the swing rod 11 can rotate synchronously with the output shaft of the hydraulic swing oil cylinder 10.

[0043] In use, the hydraulic swing oil cylinder 10 drives the swing rod 11 to rotate, the swing rod 11 drives the guide plate seat 8 to move linearly along the track 9 through the inclined rod 13, and the adjustment of the spacing between the guide plates can be realized through the movement of the guide plate seat 8.

[0044] In an optional embodiment of the application, the track 9 is provided with a worm and gear device 15 on the side close to the guide plate 3, the worm and gear device 15 comprises a worm wheel and a worm, a motor main shaft is in transmission connection with the worm, the worm is in transmission connection with the worm wheel, the worm wheel is in transmission connection with a lead screw, the lead screw 16 is sleeved in the worm wheel, and the lead screw 16 is arranged in parallel with the extension direction of the track 9. In use, when the guide plate seat moves to the set position, on one hand, the hydraulic locking device of the guide plate seat locks the guide plate seat, and on the other hand, the worm is driven to rotate through the rotation of the motor main shaft (forward transmission), the worm drives the worm wheel to rotate, the worm wheel drives the lead screw 16 to move linearly along the track 9, and the lead screw 16 is in abutting connection with the mounting frame 14 in the direction of the track 9, so as to realize the limiting of the adjusting mechanism.

[0045] When the position of the guide plate seat 8 needs to be adjusted, the motor spindle is reversed to separate the lead screw 16 from the mounting frame 14.

[0046] In other embodiments of the present application, the adjustment mechanism can also be a crank slider mechanism.

[0047] In an optional embodiment of the present application, when producing a ∮270mm blank, a steel pipe wall thickness of 25mm or less, the guide plate distance is 270mm or less (for example: 270mm, 269.9mm, 269.8mm, 269.7mm, 269.6mm, 269.5mm, 269.4mm, 269.3mm, 269.2mm, 269.1mm, 269mm, 268.5mm, 268mm, 267mm, 266mm or 265mm); when producing a ∮330mm blank, a steel pipe wall thickness of 25mm or less, the guide plate distance is 330mm or less (for example: 330mm, 329.9mm, 329.8mm, 329.7mm, 329.6mm, 329.5mm, 329.4mm, 329.3mm, 329.2mm, 329.1mm, 328.9mm, 328.8mm, 328.7mm, 328.6mm, 328.5mm, 328mm, 327mm, 326mm or 325mm).

[0048] In the prior art, when producing a ∮270mm blank, a steel pipe wall thickness of 25mm or less, the guide plate distance value is 275mm, and the wall thickness eccentricity value is up to 5mm; when producing a ∮330 blank, a wall thickness of 25mm or less, the guide plate distance value is 335mm, and the wall thickness eccentricity value is up to 6mm. Because of the wall thickness deviation, scrap and unprocessed products occur from time to time. Because of the wall thickness deviation, the production process needs to be adjusted many times, causing the quality to be passive and affecting the production yield.

[0049] The core key link of preventing wall thickness eccentricity of a thin-walled pipe in piercing is the control of the guide plate distance of the piercer. The significant influence degree of the wall thickness deviation of a thin-walled pipe in production has not been identified, and the importance of the control has not been verified. The present application has obtained satisfactory control effect through practice, is practical, simple and effective.

[0050] The design idea of the present application is to limit the shaking of the piercer in the piercing roll by using a smaller guide plate distance when producing a thin-walled pipe, so that the piercer is stable when participating in the piercing deformation. After using the present application, the wall thickness deviation of the steel pipe is stabilized within 2mm, and the eccentricity is solved.

[0051] The present application can produce the benefit: absolute scrap elimination, reduce scrap 54 tons, according to the current scrap steel price 3000 yuan, sales price 6000 yuan, the value of 16.2 million yuan. Reduce the 197 tons of product to be handled, processing fee 300 yuan / t, the disposal fee of 5.91 million yuan. Improve production efficiency, the same specification thin-walled pipe same shift more production 76, each weight 1.21 tons, can produce 91.96 tons, sales price 6000 yuan / t, the value of 55.176 million yuan.

[0052] In an alternative embodiment of the present application, the guide plate 3 comprises an entry cone 4, an exit cone 5 and a rolling band.

[0053] The entry cone 4 is located at the front part of the guide plate 3. The entry cone 4 mainly plays a role of guiding the tube blank and aligning the center of the tube blank with the center line of the piercing. When the tube blank contacts the two guide plates 3, the ellipticity of the tube blank is limited, which not only prevents the "cavity" from forming too early, but also promotes the longitudinal extension of the metal. The exit cone 5 of the guide plate 3 plays a role of limiting the transverse deformation of the pipe blank, promotes the longitudinal deformation, and can control the outer diameter of the pipe blank. The rolling band is located at the junction of the entry cone 4 and the exit cone 5, and the rolling band plays a transition role of connecting the front and rear entry cone 4 and exit cone 5. The position of the rolling band corresponds to the rolling band of the roller, is a measurement reference point for controlling the distance of the guide plate, and is a key position for preventing the shaking of the top head matched therewith.

[0054] The design of the shape and size of the guide plate 3 must meet the requirements of the deformation process of the piercing. Generally, the deformation zone of the piercing mill is symmetrical, and therefore, the shape and size of the two guide plates 3 are the same. The design of the guide plate 3 includes determining the following contents: the width of the guide plate 3, the longitudinal section shape and size of the guide plate 3, and the shape and size of each cross section. The size of the pierced pipe is different, and therefore, the size of the deformation zone is different, and thus the size of the guide plate 3 is also different. Even if the diameter of the tube blank is the same, the compression amount is different, and therefore, the width of the guide plate 3 should also be changed. In actual production, in order to reduce the size specifications of the guide plate 3, facilitate manufacturing and management, the size of the guide plate 3 is designed according to the case of piercing the pipe blank with the smallest wall thickness (the outer diameters are the same or similar). This is because when piercing the thin-walled pipe blank, the compression amount of the tube blank is the largest, and the gap between the guide plate 3 and the roller is required to be the smallest. If the gap is too large, the pipe blank is easily scratched, and even the "chain belt" accident (the metal wound on the roller due to the pipe blank being scratched, resulting in the stop of production) occurs. The guide plate 3 for rolling the thin-walled pipe blank is completely applicable to rolling the thick-walled pipe blank, although the gap between the guide plate 3 and the roller is larger at this time, but since the wall of the thick-walled pipe blank is thicker, there is no danger (such as "chain belt" and the like).

[0055] Further, the width of the guide plate 3 can be increased to reduce the gap between the guide plate 3 and the roller (the upper roller 1 and the lower roller 2), so that the metal is not easy to run out during piercing, and the passive interruption of production or the occurrence of production accidents is avoided. And at the same time, the width value of the guide plate 3 after the increase is also applicable to the production of thick-walled pipes.

[0056] In an alternative embodiment of the guide plate device in the present application, when producing a ∮270mm blank, a steel pipe wall thickness of 25mm or less specification, the width of the guide plate 3 is 225-250cm (for example: 225cm, 228cm, 229cm, 230cm, 232cm, 233cm, 235cm, 240cm, 245cm or 250cm); preferably, the width of the guide plate 3 is 230cm, which is increased by 10cm compared with the prior art. When producing a ∮330mm blank, a steel pipe wall thickness of 25mm or less specification, the width of the guide plate 3 is 275-290cm (for example: 275cm, 278cm, 279cm, 280cm, 281cm, 282cm, 285cm, 290cm), preferably, the width of the guide plate 3 is 280cm.

[0057] In an alternative embodiment of the guide plate device in the present application, the taper angle of the inlet cone 4 is 2-4° (for example: 2°, 2.5°, 2.6°, 2.7°, 2.8°, 2.9°, 3°, 3.1°, 3.2°, 3.3°, 3.4°, 3.5° or 4°), preferably, the taper angle of the inlet cone 4 is 2.5-3.5°; most preferably, the taper angle of the inlet cone 4 is 3°.

[0058] The taper angle of the outlet cone 5 is 2.5-4° (for example: 2.5°, 2.8°, 3°, 3.1°, 3.2°, 3.3°, 3.4°, 3.5°, 3.6°, 3.7°, 3.8°, 3.9° or 4.0°); preferably, the taper angle of the outlet cone 5 is 3-3.5°.

[0059] Due to the large deformation, large ovality and large diameter expansion during the production process of the thin-walled pipe piercing mill, the prior art has the following defects: the guide plate 3 locally forms a nodule and scratches the spiral skin. In the prior art, the above defects are only solved by relying on the cooling water of the guide plate 3, but it cannot fundamentally eliminate the defects and it is difficult to achieve the desired effect.

[0060] In order to solve the above defects, the surface of the guide plate 3 can be subjected to a strengthening treatment.

[0061] In an alternative embodiment of the present application, the surface of the guide plate 3 is provided with a surface strengthening layer, which is any one of a laser cladding layer, an argon arc cladding layer, a surface overlaying layer or an electroplating layer.

[0062] Preferably, the surface strengthening layer is a laser cladding layer. In the present application, the laser cladding technology is used on the surface of the guide plate 3 for the first time. After laser cladding, the strength and hardness of the guide plate 3 are improved, and under the combined action of the cooling water of the guide plate 3, the local nodule on the surface of the guide plate 3 is essentially solved, and the effect is obvious.

[0063] In an alternative embodiment of the present application, the surface strengthening layer is a particulate reinforced metal matrix composite. The particulate reinforcement of the particulate reinforced metal matrix composite is ceramic, which is one or more of carbide, oxide, boride, nitride; preferably, the ceramic is carbide, which is one or more of TiC, WC, VC, SiC, B4C, ZrC.

[0064] Preferably, the ceramic is nanoceramic.

[0065] The matrix material of the particulate reinforced metal matrix composite is one or more of titanium, iron-aluminum alloy, iron, magnesium, nickel; preferably, the matrix material of the particulate reinforced metal matrix composite is iron.

[0066] Since iron is less expensive and carbide has good wettability with iron matrix, in an alternative embodiment of the present application, the particulate reinforced metal matrix composite is a carbide particulate reinforced iron matrix composite.

[0067] In an alternative embodiment of the present application, the particulate reinforced metal matrix composite is a laser cladding layer, which is prepared by laser cladding technique. The material used in laser cladding is nanoceramic metal powder, and the laser cladding layer is a metal matrix particulate reinforced composite.

[0068] In an alternative embodiment of the present application, the particulate reinforcement is in-situ self-generating particulate reinforcement or exogenous particulate reinforcement. Preferably, the particulate reinforcement is in-situ self-generating particulate reinforcement. This is because in-situ self-generating particulate reinforcement has the advantages of high bonding strength with the matrix and high dispersion distribution.

[0069] In a preferred embodiment of the present application, the raw materials for laser cladding include: iron-based alloy powder 35-70 parts by weight (for example: 40, 42, 45, 48, 50, 52, 55, 58, 60, 62, 65, 68 or 70), Ti powder 25-40 parts by weight (for example: 25, 28, 30, 33, 35, 38 or 40), graphite 5-15 parts by weight (for example: 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 or 15), W powder 5-10 parts by weight (for example: 5, 6, 7, 8, 9 or 10). The raw materials are respectively subjected to ball milling treatment. The iron-based alloy powder is WF372 iron-based alloy powder, which includes, according to mass percentage: C: 3.3-4.3%, Cr: 23-26%, B: 1.0-2.0%, Si: 1.0-2.0%, Ni: 4.0-6.0%, and the rest is Te. Laser cladding forms a composite carbide particle reinforced iron-based surface cladding layer. The in-situ self-generated particle reinforcements include composite carbides, which have the crystal structure of TiC and are solid-soluted with elements such as B, W and Cr, i.e. intermetallic compounds are formed. The in-situ self-generated particle reinforcements also include CrB, TiB, (Fe, Cr)7C3, etc.

[0070] In a preferred embodiment of the present application, the raw materials for laser cladding include: iron-based alloy powder 30-70 parts by weight (for example: 40, 42, 45, 48, 50, 52, 55, 58, 60, 62, 65, 68 or 70), graphite 5-15 parts by weight (for example: 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 or 15), WO3 powder 15-55 parts by weight (for example: 15, 18, 20, 25, 30, 35, 40, 45, 50 or 55). The in-situ self-generated particle reinforcements include Fe6W6C, Fe3W3C, WC, (Fe, Cr)7C3.

[0071] Since the partial protuberance of the guide plate 3 is located in the outlet area, in order to save costs, in an optional embodiment of the present application, only the surface of the outlet cone 5 of the guide plate 3 is provided with a surface strengthening layer, and the inlet cone 4 of the guide plate 3 is not provided with a surface strengthening layer.

[0072] Since laser cladding has the advantages of small dilution degree, small heat input, short heat cycle, and small thermal damage and thermal deformation to the substrate, it is easy to select area cladding. Therefore, even if only the inlet cone 4 is provided with a surface strengthening layer, it will not cause structural deformation of the whole guide plate 3 by using laser cladding technology.

[0073] In another optional embodiment of the present application, the surfaces of the outlet cone 5 and the inlet cone 4 of the guide plate 3 are both provided with surface strengthening layers.

[0074] In the prior art, when the wall thickness of the thin-walled pipe is less than 25 mm, the outer surface of the steel pipe is prone to spiral scratches, and the one-time qualified rate of the magnetic particle inspection of the outer surface of the thin-walled pipe is only 21.3%, which affects the quality of the outer surface of the steel pipe and leads to the repair of the finishing process, affects the delivery time and increases the process cost.

[0075] In the present application, after the guide plate 3 is laser strengthened, the one-time qualified rate of the magnetic particle inspection of the outer surface of the thin-walled pipe is 98.28%, the repair is reduced, the quality is improved, the cost is effectively reduced, the thin-walled pipe is produced at an average of 3331 tons per month, the outer grinding cost is 116.4 yuan / ton, the magnetic particle inspection cost is 15 yuan / ton, and the monthly cost reduction is 33.693 million yuan. Annual benefit is 33.693*12=404.316 million yuan.

[0076] Further, in order to facilitate the movement and transportation of the guide plate 3, the guide plate 3 is provided with lifting screw holes 7, the lifting screw holes 7 are two, the lifting screw holes 7 are located on both sides of the width direction of the guide plate 3 and are located at the position of the rolling strip.

[0077] In the present application, the specific embodiment of the piercing mill for producing thin-walled seamless steel pipes is as follows:

[0078] As shown in Figures 2-4 A piercing mill for producing thin-walled seamless steel pipes, comprising any one of the guide plate devices described above. The piercing mill further comprises a roll, the roll is divided into an upper roll 1 and a lower roll 2, the upper roll 1, the lower roll 2 and the guide plate 3 device enclose a piercing area for the pipe blank to pass through. Specifically, the upper roll 1 and the lower roll 2 are arranged in an upper and lower interval, and the two guide plates 3 are arranged in a left and right interval.

[0079] It can be understood that the above description is only exemplary, and the embodiments of the present application do not limit this.

[0080] The above description is only a preferred embodiment of the present application and does not limit the present application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application is within the scope of the claims of the present application.

Claims

1. A guide plate device for producing thin-walled seamless steel pipes, characterized in that, The guide plate device comprises guide plates, two of which are oppositely spaced apart for the pipe blank to pass through, and are fixedly installed on corresponding guide plate seats, at least one of which is connected with an adjusting mechanism, and the spacing between the two guide plates is adjusted by the adjusting mechanism; The guide plate seat is installed on a track, and the adjusting mechanism comprises a hydraulic swing oil cylinder, which is arranged below the track, the output shaft of the hydraulic swing oil cylinder is connected with one end of a swing rod, the other end of the swing rod is provided with a mounting hole, a horizontal rod is inserted into the mounting hole, the two end portions of the horizontal rod are provided with inclined rods, the lower end of the inclined rod is fixedly connected with the horizontal rod, the upper end of the inclined rod is hingedly connected with a mounting frame, and the mounting frame is fixedly connected with the guide plate seat; the swing rod can rotate synchronously with the output shaft of the hydraulic swing oil cylinder; The swing rod is driven to rotate by the hydraulic swing oil cylinder, so that the guide plate seat is driven to move linearly along the track by the inclined rod; A worm and gear device is arranged on the outside of the track near the guide plate, The worm and gear device comprises a worm wheel and a worm, the main shaft of the motor is in transmission connection with the worm, the worm is in transmission connection with the worm wheel, the worm wheel is in transmission connection with a lead screw, and the lead screw is arranged in parallel with the track; When the guide plate seat moves to the set position, the hydraulic locking device of the guide plate seat locks the guide plate seat; The worm is driven to rotate by the rotation of the main shaft of the motor, the worm drives the worm wheel to rotate, and the worm wheel drives the lead screw to move linearly in the direction of the track, so that the lead screw and the mounting frame are in abutting connection in the direction of the track; The spacing between the two guide plates is a guide plate distance, When producing a pipe blank with a diameter of 270 mm and a wall thickness of 25 mm or less, the guide plate distance is 270 mm or less; When producing a pipe blank with a diameter of 330 mm and a wall thickness of 25 mm or less, the guide plate distance is 330 mm or less; When producing a pipe blank with a diameter of 270 mm and a wall thickness of 25 mm or less, the width of the guide plate is 225-250 cm; When producing a pipe blank with a diameter of 330 mm and a wall thickness of 25 mm or less, the width of the guide plate is 275-290 cm; The surface of the guide plate is provided with a surface strengthening layer, which is any one of a laser cladding layer, an argon arc cladding layer, a surface overlaying layer or an electroplating layer; The material of the surface strengthening layer is a particle reinforced metal matrix composite, the particle reinforcement of the particle reinforced metal matrix composite is ceramic, and the ceramic is one or more of carbide, oxide, boride and nitride; the base material of the particle reinforced metal matrix composite is one or more of titanium, iron-aluminum alloy, iron, magnesium and nickel.

2. The guide device for producing a thin-walled seamless steel pipe according to claim 1, characterized by The guide plate is fixedly connected to the guide plate seat in a detachable manner, so as to replace the guide plate according to the wall thickness of the pipe blank.

3. The guide device for producing a thin-walled seamless steel pipe according to claim 1, characterized by The guide plate comprises an inlet cone and an outlet cone, the taper angle of the inlet cone is 2-4°, and the taper angle of the outlet cone is 2.5-4°.

4. The guide device for producing a thin-walled seamless steel pipe according to claim 1, characterized by The surface strengthening layer is located on the surface of the outlet cone of the guide plate; and the surface strengthening layer is a laser cladding layer. The particulate reinforcement is an in-situ particulate reinforcement, the in-situ particulate reinforcement being a complex carbide.

5. A piercing mill for producing thin-walled seamless steel pipes, characterized in that, The piercing mill comprises the strip guide arrangement according to any one of claims 1 to 4, the piercing mill further comprising a roll, the roll comprising an upper roll and a lower roll, the upper roll, the lower roll and the strip guide arrangement enclosing a piercing area for the passage of the pipe blank.

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