Oblique piercing production method of super austenite seamless steel pipe

Abstract

The invention discloses a cross piercing production method of an S31254 super austenite seamless steel pipe. The cross piercing production method comprises the steps of blank outer surface treatment, saw cutting, centering and other blank cross piercing pretreatment; heating: according to material characteristics, setting heating temperatures and heating time of a preheating section, a heating section and a soaking section for heating the inclined hearth furnace so as to achieve ideal high-temperature structure properties; in the cross piercing process, key parameters set in the production process of piercing are defined, and in the cooling treatment, the cooling mode and the highest temperature of cooling termination are determined. The roller design comprises the degrees of an inlet rolling angle and an outlet rolling angle of the roller, the diameter size of the working tape roller and the like. By means of the series of steps and tool and die design, the steel pipe with the quality meeting the standard requirement is successfully produced through the material on a perforating machine.

Description

Technical Field

[0001] The invention relates to the technical field of seamless steel pipe preparation, and in particular to a method for producing a super austenitic seamless steel pipe by oblique rolling and perforation. Background Art

[0002] S31254 is a super austenitic stainless steel. Due to its high Mo content, it has better resistance to acid corrosion, pitting corrosion, crevice corrosion, stress corrosion and general corrosion than conventional austenitic stainless steel. It is widely used in seawater desalination, papermaking and bleaching industries.

[0003] Due to its relatively high content of Ni, Cr, Mo, N, etc., its yield strength and tensile strength are higher than those of conventional austenitic stainless steel, it has great resistance to high-temperature deformation and a narrow hot working temperature range. At present, it is mainly produced by extrusion. However, the characteristics of extrusion production are large metal losses due to machining, expansion and pressing of the extruded billet. Therefore, the yield rate of extrusion production is relatively low, and the energy and auxiliary material consumption of extrusion production are relatively large.

[0004] In order to solve some or all of the technical problems existing in the above-mentioned prior art, the present invention provides a method for producing an oblique rolling and perforating S31254 super austenitic seamless steel pipe, which effectively reduces the machining amount of the blank, basically achieves no metal loss in the hot working process, and greatly improves the material yield rate. Summary of the invention

[0005] The purpose of the present invention is to provide a method for producing a super austenitic seamless steel pipe by oblique rolling and perforation in view of the above problems.

[0006] The object of the present invention is achieved in this way: a method for producing oblique rolling and perforation of a super austenitic seamless steel pipe, comprising the following steps: Step 1: outer surface treatment of the billet: the incoming round steel is subjected to peeling treatment, and the outer diameter deviation of the whole material after peeling does not exceed 1.5 mm. After peeling, the outer surface of the round steel is free of cracks and black skin, and the smoothness of the peeled surface is guaranteed; Step 2: Billet sawing: the billet sawing length is set as required, the two ends are flush, the outer diameter must be measured before marking, and the sawing is performed according to the standards of the process card. After sawing, the material information is clearly marked on the billet; Step 3: Centering: Before centering, check the incoming material situation and whether the end face cutting inclination is within the process requirements. Secondly, check whether the centering clamping device is in an eccentric state; Step 4: Heating: The heating is divided into three sections according to the different temperature ranges of the furnace, namely, the preheating section, the heating section and the soaking section; Step 5: Head design: The head design includes the maximum diameter of the head working section, the total head Length, reverse cone radian, reverse cone length, straight section length, rolling angle, rolling section length, nose arc radius, deformation section arc radius, connection thread method, connection thread size; Step six: guide plate design: the guide plate design content includes the angle between the guide plate bevel and the bottom plane, the entrance cone angle, the entrance section radian, the top radian, the exit cone angle, the exit radian, the bottom cone angle, the length from the bottom cone of the guide plate to the working surface, the entrance section width, the exit section width, the total length of the guide plate, the bite section length, and the ejection section length; Step seven: Roller design: the roll design content includes the selection of tapered roll design, roll entrance cone angle, exit cone angle, roll surface length, entrance working surface length, and working rolling center roll diameter; Step eight: oblique rolling piercing deformation process parameter setting: including the selection of the unit, the determination of the piercing specifications, the selection of the head specifications, the setting of the roll spacing, the guide plate spacing, and the head extension; Step nine: Cooling treatment: water cooling treatment after hot rolling is completed.

[0007] In step 1, the outer diameter tolerance of the blank after peeling is ±0.5mm, and the depth of the turning tool mark after peeling is <0.5mm.

[0008] In step 2, the sawing length of the blank is 2700mm-2750mm, both ends are flush, the sawing tolerance is ±1mm, and the sawing slope is <2mm.

[0009] In step 3, the inner diameter of the centering hole is 49.5mm-50.5mm, the inner hole depth tolerance is 29mm-31mm, and the eccentricity of the centering hole is ≤1mm.

[0010] In step 4, the temperature of the preheating section is 650-700°C, and the residence time is 3-4 hours; the steel temperature in the heating section is controlled at 1120-1130°C, and the residence time is 2.5-3 hours; the steel temperature in the soaking section is controlled at 1140-1150°C, and the residence time is controlled between 1.5-2 hours.

[0011] In step 5, the maximum diameter of the working section of the plug is φ109mm-φ111mm, the total length of the plug is 204mm-206mm, the reverse cone curvature is R9mm-R11mm, the reverse cone length is 8-10mm, the straight section length is 9.5-10.5mm, the rolling angle is designed to be 2.7°-3.3°, the rolling section length is 64mm-69mm, the nose arc radius is R5mm-R7mm, the deformation section arc radius is R198mm-R203mm, the connection thread method is left-handed, and the connection thread size is M64*4-M65*5.

[0012] In step six, the angle between the hypotenuse of the guide plate and the bottom plane is 56°-63°, the entrance cone angle is 5.3°-5.6°, the entrance section curvature is R107mm-R112mm, the top curvature is R106mm-R111mm, the exit cone angle is 2.3°-2.7°, the exit curvature is R215mm-R211mm, the bottom cone angle is 130°-133°, the length from the bottom cone of the guide plate to the working surface is 80mm-85mm, the entrance section width is 125mm-127mm, the exit section width is 167mm-172mm, the total length of the guide plate is 558mm-663mm, the bite section length is 207mm-212mm, and the ejection section length is 348mm-353mm.

[0013] In step seven, the rolling rollers are designed as tapered rollers, with an inlet cone angle of 2.6°-2.9°, an outlet cone angle of 2.9°-3.2°, a roller surface length of 745mm-751mm, an inlet working surface length of 306mm-308mm, and a working rolling center roller diameter of 992mm-1013mm.

[0014] In step eight, the roller spacing is 131.4mm-132.2mm, the guide plate spacing is 147.5mm-149mm, and the top head extension is 64mm-66mm.

[0015] In step nine, the circulating water temperature does not exceed 50°C.

[0016] The beneficial effects of the present invention are as follows: 1) The present invention realizes the production of S31254 super austenite seamless steel pipe by oblique rolling and perforation, rather than by extrusion. The production by oblique rolling and perforation achieves the goal of high yield rate of the material.

[0017] 2) The present invention realizes heating of the material by controlling the heating mode of the inclined bottom furnace.

[0018] 3) The present invention realizes the deformation of the steel grade S31254 by designing relevant tools and dies, including the design of the head, the guide plate and the roller deformation tools and dies.

[0019] 4) The present invention sets various deformation parameters of the oblique rolling piercing machine, creating and realizing good deformation conditions for the material.

[0020] S31254 is currently produced by extrusion, which is characterized by the need to prepare the blanks for arc, bell mouth and deep hole losses, and the expansion and compression excess metal losses will also be formed during the hot hole expansion and hot extrusion process. The yield rate of seamless square tubes obtained by extrusion is about 85%. The production is carried out by oblique rolling and perforation, and there is basically no metal loss in the blank preparation process, and the loss in the perforation process can be basically ignored, and the final perforation yield rate is above 96%. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The drawings described herein are used to provide a further understanding of the embodiments of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings: Figure 1 The present invention is a schematic diagram of the plug design of a production method of a S31254 super austenitic seamless steel pipe.

[0022] Figure 2 This is a schematic diagram of the guide plate design in the production method of S312554 super austenitic seamless steel pipe of the present invention.

[0023] Figure 3 The present invention is a schematic diagram of the design of a rolling roller in a method for producing a S31254 super austenitic seamless steel pipe. DETAILED DESCRIPTION

[0024] Since the Mo content of S31254 super austenitic seamless steel pipe is as high as 6%, and it contains N elements, the material has a very high resistance to high-temperature deformation. However, its melting point is relatively low, resulting in a very narrow heating range. Extrusion production is carried out in the direction of three-way compressive stress. The tendency of the billet to produce cracks during the production process is very small, and the 6,000-ton extrusion force can provide sufficient thrust to overcome the deformation resistance. Even when the billet extrusion temperature is low, the billet deformation resistance can be overcome. When in the high-temperature section of the billet, due to the stress characteristics of its three-way compressive stress, the possibility of cracking is even smaller. In this way, when produced by extrusion, the hot working range of the material is very wide, even to the range of 70°C-100°C.

[0025] However, the biggest disadvantage of the extrusion production method is the low yield rate. Metal loss includes three aspects: cold processing loss, heating loss, and hot processing waste loss caused by process design. Among them, cold processing loss includes: arc loss of the billet end face, billet deep hole loss and bell mouth loss of the billet end face. Waste loss in the extrusion process includes: expansion excess and compression excess. The total loss above is between 13% and 15%.

[0026] The deformation characteristics of oblique rolling and piercing are two-way compressive stress and one-way tensile stress. The production method adopts the principle of creating a cavity in the middle of an ellipse turning into a circle. When producing steel pipes in this way, crack defects are very likely to occur inside the pipe. In order to avoid the occurrence of defects in the inner hole of the pipe, cooling measures are usually adopted for production. However, for steel types with relatively high resistance to high-temperature deformation, low temperature will cause the deformation resistance to be greater than the friction force provided by the roller to the blank, causing the blank to be stuck.

[0027] However, the advantages of oblique rolling and piercing are also obvious, that is, the yield rate of the billet is very high, the loss of the billet processing is only between 1% and 3%, the burning loss does not exceed 1%, and the total yield rate can reach more than 96%, which can increase the yield rate by 10% compared with extrusion production.

[0028] For super austenitic stainless steel such as S31254, which has high deformation resistance and a narrow hot working temperature range, if stable production can be achieved through perforation, it will be pioneering and of great significance.

[0029] Therefore, we set technical requirements for billet processing and preparation to ensure the surface conditions of billet production and good force preparation conditions. Secondly, according to the material characteristics, set accurate heating temperature and heating time to make the billet's high-temperature deformation resistance relatively low without causing rapid grain growth. Finally, through the design of the tool and die, the tool and die have better streamlines, more in line with the deformation angle and matching the rolling mill parameters that are consistent with the tool and die design, making the billet deformation process smoother, dispersing the deformation resistance, and less prone to cracks in the inner hole, so that the oblique rolling and piercing of the seamless steel pipe of this material can be smoothly implemented.

[0030] The present invention provides an oblique rolling and perforating method for S31254 seamless steel pipes, and the technical scheme of the invention is as follows: 1. The outer surface treatment of the billet is to peel the incoming round steel, and the outer diameter of the billet after peeling is ±0.5mm. The setting of the peeling outer diameter tolerance affects the bite and rolling stress process of the perforated billet when the perforation parameters are set later. The depth of the turning tool mark after peeling is less than 0.5mm to ensure that there are no cracks on the outer surface after rolling, and the surface unevenness defects are generated. There are no obvious cracks or black skin on the outer surface, and the smoothness of the peeled surface is guaranteed. The outer diameter deviation of the entire material after peeling shall not exceed 1.5mm. This tolerance ensures that the force of the billet is more uniform during the transformation from round steel to pipe.

[0031] 2. Billet sawing, the billet sawing length is set according to the pipe demand, both ends are flush, the outer diameter must be measured before marking, sawing is carried out according to the standards of the process card, and the material information is clearly marked on the billet after sawing. The billet sawing length is 2750mm, both ends are flush, and the sawing tolerance is ±1mm. If the tolerance is too large, the set steel pipe length will not be enough to meet the final length dimension requirements. The sawing slope is <2mm, and the tolerance setting of the sawing slope ensures the centering degree during the centering process.

[0032] 3. Before centering, the incoming material must be checked to see if the end face cutting inclination is within the process requirements. Secondly, check whether the centering clamping device is eccentric. The centering hole size is D50mm*30mm, the inner hole diameter tolerance is ±0.5mm, the inner hole depth tolerance is ±1mm, the centering hole eccentricity is ≤1mm, the centering hole is required to be smooth and burr-free, and the centering hole accuracy deviation directly affects the wall deviation of the rolled steel pipe head.

[0033] 4. Heating is divided into three sections according to the different temperature ranges of the furnace, namely the preheating section, the heating section and the soaking section. The heating temperature and heating time of each section are set according to the material properties, the outer diameter of the billet and the specifications of the rough pipe to be produced. The temperature of the preheating section is 650-700℃, and the furnace time is 3-4 hours; the steel temperature of the heating section is controlled at 1120-1130℃, and the furnace time of this section is 2.5-3 hours; the steel temperature of the soaking section is controlled at 1140-1150℃, and the furnace time is controlled between 1.5-2 hours. Since the Cr and Ni content in the material is very high, and the Mo content exceeds 3% of ordinary duplex steel to reach 6%, this alloy characteristic causes its hot working temperature range to be very narrow and the deformation resistance to be very large, so it is very important to choose the best heating temperature and heating time.

[0034] 5. The design of the plug includes the maximum diameter of the plug working section, the total length of the plug, the anti-cone radian, the anti-cone length, the length of the straight section, the rolling angle, the length of the rolling section, the radius of the nose arc, the radius of the deformation section arc, the connection thread method, and the size of the connection thread. The maximum diameter of the plug working section should be determined according to the gap between it and the inner diameter of the rough pipe during the rolling process. The length of the plug directly determines the number of rolling times of the rough pipe during the rolling process. The maximum diameter of the plug working section is φ110mm, the total length of the plug is 205mm, the anti-cone radian is R10mm, and the anti-cone length is 9mm. Such an radian and length will prevent the rough pipe from scratching the inner hole of the rough pipe when it is separated from the plug. The straight section length is 10mm. Although the straight length of the plug does not participate in the deformation process of the rough pipe, it is crucial in the process of the rough pipe returning to a round shape. The rolling angle is designed to be 3°, and the rolling section length is 65mm to ensure the smooth expansion of the inner hole. The radius of the nose arc is R5mm, and the design of this arc radius should match the looseness in the middle formed during the elliptical deformation of the rough pipe. The radius of the deformation section arc is R200mm, and the design of this arc is the gradual curve arc from the tube blank bar to the tube, which needs to be determined according to the size of the rough pipe specification of the material. The connection thread method is left-handed, and the connection thread size is M64*4, which ensures that the transition connection between the plug and the ejector rod is reliable and does not affect the strength of the plug end.

[0035] 6. The design of the guide plate includes the angle between the bevel of the guide plate and the bottom plane, the entrance cone angle, the curvature of the entrance section, the curvature of the top end, the exit cone angle, the exit curvature, the bottom cone angle, the length from the bottom cone of the guide plate to the working surface, the width of the entrance section, the width of the exit section, the total length of the guide plate, the length of the bite section, and the length of the throw section. The angle between the bevel of the guide plate and the bottom plane is 60°. The design of this angle must match the angle of the guide plate frame, and its degree design must ensure the stability of the guide plate fixed by the guide plate frame. The entrance cone angle is 5.4°. This angle design ensures the smooth bite of the billet and the roller at one time while meeting the perforation and rolling parameters. The entrance section curvature is R109mm, and the top curvature is R109mm. The design of these two curvatures is closely related to the diameter and ovality of the billet. The exit cone angle is 2.5°, and the exit curvature is R218mm. This cone angle is designed to ensure the roundness of the rough pipe during the forming process. The bottom cone angle is 130°, and the size of this cone angle ensures the close fit between the guide plate and the guide plate frame. The length from the bottom cone of the guide plate to the working surface is 80mm. The thickness is designed to meet the strength requirements of the guide plate itself on the one hand, and the travel problem of the guide plate distance on the other hand. The entrance section width is 126±1mm, the exit section width is 170mm, and the total length of the guide plate is 560mm. The design of these three parameters allows the guide plate to fit according to the angle of the roller, ensuring that the rough pipe will not wear the roller during the deformation process, and will not cause the possibility of chain belts during the rough pipe forming process. The length of the bite section is 210mm, and the length of the throw section is 350mm. The design of these two lengths is to meet the problem of force distribution of the rough pipe on the guide plate during the deformation process.

[0036] 7. The design of the rolls includes the tapered roll design, roll inlet cone angle, outlet cone angle, roll surface length, inlet working surface length, and working rolling center roll diameter. The rolls are designed with tapered rolls, with an inlet cone angle of 2.7° and an outlet cone angle of 3°. The design of these two angles largely determines the diameter of the billet and the expansion of the rough pipe after perforation. The roll surface length is 750mm and the inlet working surface length is 307mm. These two dimensions ensure the deformation span from the billet to the rough pipe, allowing the rough pipe to be fully deformed. The working rolling center roll diameter is 1000mm, and the large roll diameter design of the 160 unit ensures the contact width between the roll and the billet, making the deformation force of the billet uniform.

[0037] 8. Setting parameters of oblique rolling perforation deformation process: including the selection of the unit, the determination of perforation specifications, the selection of plug specifications, the setting of roll spacing, guide plate spacing and plug extension. The perforator uses a larger 160 perforation unit, which has a larger roller body and a larger width, so that the surface quality of the perforated rough pipe is better. The selection of perforation specifications and plugs must ensure the gap between the rough pipe and the plug, so that the perforation deformation is smoother and the core of the rough pipe is effectively not torn too much. Reasonable roll spacing setting provides sufficient longitudinal pressure for the smooth passage of the tube blank and ensures the friction force of the rough pipe spiral forward. The size of the guide plate spacing and the billet are set according to the outer diameter of the billet and the size of the roll spacing. The reasonable setting of the plug extension not only ensures the smooth bite of the perforation, but also ensures that the center of the billet will not be overly torn before the second bite. Specifically: roll spacing 132mm, guide plate spacing 148mm, plug extension 65mm.

[0038] 9. Cooling treatment: After hot rolling, the steel pipe is cooled in water. The circulation and cooling of the water flow in the cooling pool should be controlled, and the circulating water temperature should not exceed 50°C, so that the water temperature is low enough to meet the cooling speed of the billet after rolling, so as to ensure that the steel pipe forms a good solid solution effect.

[0039] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the specific embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0040] The technical solution provided by the embodiments of the present invention is described in detail below with reference to the accompanying drawings. Example 1

[0041] (1) Billet outer surface treatment: The incoming round steel is peeled. The outer diameter of the billet after peeling is φ148±0.5mm. The depth of the turning tool mark after peeling is less than 0.5mm. There are no obvious cracks or black skin on the outer surface. The outer diameter deviation of the whole billet after peeling shall not exceed 1.5mm.

[0042] (2) Sawing: The sawing length of the blank is 2750mm, and both ends are flush. The outer diameter must be measured before marking. Sawing is carried out according to the standards on the process card. After sawing, the material information is clearly marked on the blank. The sawing tolerance is ±1mm; the sawing slope is <2mm.

[0043] (3) Centering: Before centering, the incoming material must be checked to see if the end face cutting inclination is within the process requirements. Secondly, check whether the centering clamping device is eccentric. The centering hole size is D50mm*30mm, the inner hole diameter tolerance is ±0.5mm; the inner hole depth tolerance is ±1mm, the centering hole eccentricity is ≤1mm, and the centering hole is required to be smooth and free of burrs.

[0044] (4) Heating: Heating is divided into three sections according to the different temperature ranges of the furnace, namely preheating section, heating section and soaking section. The heating temperature and heating time of each section are shown in the following table.

[0045]

[0046] (5) Design and selection of oblique rolling piercing tools: 5.1 Design of plug: The maximum diameter of the plug working section is φ110mm, the total length of the plug is 205mm, the reverse cone radius is R10mm, the reverse cone length is 9mm, the straight section length is 10mm, the rolling angle is designed to be 3°, the rolling section length is 65mm, the nose arc radius is R5mm, the deformation section arc radius is R200mm, the connection thread method is left-handed, and the connection thread is M64*4.

[0047] 5.2 Guide plate design: The included angle between the bevel of the guide plate and the bottom plane is 60°, the inlet cone angle is 5.4°, the inlet section curvature R109mm, the top curvature R109mm, the outlet cone angle is 2.5°, the outlet curvature R218mm, the bottom cone angle is 130°, the length from the bottom cone of the guide plate to the working surface is 80mm, the inlet section width is 126±1mm, the outlet section width is 170mm, the total length of the guide plate is 560mm, the bite section length is 210mm, and the ejection section length is 350mm.

[0048] 5.3 Roller design: The roller is designed with a tapered roller, with an inlet cone angle of 2.7°, an outlet cone angle of 3°, a roller surface length of 750mm, an inlet working surface length of 307mm, and a working rolling center roller diameter of 1000mm.

[0049] (6) The piercing and rolling parameters are set as shown in the following table.

[0050]

[0051] (7) Cooling treatment: After hot rolling is completed, the steel should be immediately put into water. The water in the cooling pool should be circulated, and the circulating water temperature should not exceed 50°C.

[0052] Through the above steps, 155*20 rough pipes were successfully produced. The inner and outer walls of the produced steel pipes had no cracks, meeting the quality requirements of oblique rolled perforated steel pipes.

[0053] The losses in this process include peeling, sawing, centering, burning, piercing and rolling wear. Comparing the weight of the rough steel pipe with the weight of the steel billet, the yield rate is as high as 97.59%. Example 2

[0054] This case is a plan for producing steel pipes of the same specification of 155*20 through extrusion: (1) Sawing: The sawing length of the billet is 790mm, with both ends flush, and a 7650 sawing machine is used for cutting production.

[0055] (2) Deep hole: The deep hole of the blank must penetrate the entire blank. The size of the deep hole should be 60mm, and the eccentricity of the deep hole should be ≤1.5mm.

[0056] (3) Arc: One end of the blank needs to be rounded, and the arc radius is R30mm.

[0057] (4) Bell mouth: The bell mouth is machined on the same side of the arc end of the blank, and the maximum diameter of the bell mouth cone is 135 mm.

[0058] (5) Hole expansion: The hole expansion cone is 130 mm, and the hole expansion produces a 200 mm expansion surplus.

[0059] (6) Extrusion: The extrusion needle is 117.5mm, the extrusion die is 159mm, the extrusion residual diameter is 290mm, and the length is 230mm.

[0060] The material loss process of the extruded steel pipe 155*20 produced by the above steps includes: sawing, deep hole, arc, ring furnace burning, induction furnace burning, expansion loss, and pressure loss. By comparing the weight of the extruded rough pipe 155*20 with the 790mm billet, the yield rate is 86.82%.

[0061] The above description is only a specific embodiment of the present invention, but the structural features of the protection scope of the present invention are not limited thereto. Any changes or modifications made by any technician in the field of the present invention are all covered by the patent scope of the present invention.

Claims

1. A method for producing super austenitic seamless steel pipe by oblique rolling and perforation. Features: The following steps are involved: Step 1: Billet outer surface treatment: peel the incoming round steel. After peeling, the outer diameter deviation of the whole material does not exceed 1.5mm. After peeling, there are no cracks or black skin on the outer surface of the round steel to ensure the smoothness of the peeled surface. Step 2: Billet sawing: The billet sawing length is set as needed, and both ends are flush. The outer diameter must be measured before marking. The billet is sawed according to the standards of the process card. After sawing, the material information is clearly marked on the billet. Step 3: Centering: Before centering, check the incoming material and whether the end face cutting angle is within the process requirements. Secondly, check whether the centering clamping device is eccentric. Step 4: Heating: Heating is divided into three sections according to the different temperature ranges of the furnace, namely preheating section, heating section and soaking section; Step 5: Plug design: Plug design includes the maximum diameter of the plug working section, the total length of the plug, the arc of the reverse cone, the length of the reverse cone, the length of the straight section, the rolling angle, the length of the rolling section, the radius of the nose arc, the radius of the deformation section arc, the connection thread method, and the size of the connection thread; Step 6: Guide plate design: The guide plate design includes the angle between the guide plate bevel and the bottom plane, the entrance cone angle, the entrance section curvature, the top curvature, the exit cone angle, the exit curvature, the bottom cone angle, the length from the bottom cone of the guide plate to the working surface, the entrance section width, the exit section width, the total length of the guide plate, the bite section length, and the throw section length; Step 7: Roller design: Roller design includes the selection of tapered roller design, roller inlet cone angle, outlet cone angle, roller surface length, inlet working surface length, and working rolling center roller diameter; Step 8: Setting parameters of oblique rolling piercing and deformation process: including the selection of the unit, the determination of piercing specifications, the selection of plug specifications, the setting of the roll distance, guide plate distance and plug extension; Step 9: Cooling treatment: After hot rolling is completed, put it into water for cooling treatment.

2. The method for producing a super austenitic seamless steel pipe by oblique rolling and perforation according to claim 1, Features: In step 1, the outer diameter tolerance of the blank after peeling is ±0.5mm, and the depth of the turning tool mark after peeling is <0.5mm.

3. The method for producing a super austenitic seamless steel pipe by oblique rolling and perforation according to claim 1, Features: In step 2, the sawing length of the blank is 2700mm-2750mm, both ends are flush, the sawing tolerance is ±1mm, and the sawing slope is <2mm.

4. The method for producing a super austenitic seamless steel pipe by oblique rolling and perforation according to claim 1, Features: In step 3, the inner diameter of the centering hole is 49.5mm-50.5mm, the inner hole depth tolerance is 29mm-31mm, and the eccentricity of the centering hole is ≤1mm.

5. The method for producing a super austenitic seamless steel pipe by oblique rolling and perforation according to claim 1, Features: In step 4, the temperature of the preheating section is 650-700°C, and the residence time is 3-4 hours; the steel temperature in the heating section is controlled at 1120-1130°C, and the residence time is 2.5-3 hours; the steel temperature in the soaking section is controlled at 1140-1150°C, and the residence time is controlled between 1.5-2 hours.

6. The method for producing a super austenitic seamless steel pipe by oblique rolling and perforation according to claim 1, Features: In step 5, the maximum diameter of the working section of the plug is φ109mm-φ111mm, the total length of the plug is 204mm-206mm, the reverse cone curvature is R9mm-R11mm, the reverse cone length is 8-10mm, the straight section length is 9.5-10.5mm, the rolling angle is designed to be 2.7°-3.3°, the rolling section length is 64mm-69mm, the nose arc radius is R5mm-R7mm, the deformation section arc radius is R198mm-R203mm, the connection thread method is left-handed, and the connection thread size is M64*4-M65*5.

7. The method for producing a super austenitic seamless steel pipe by oblique rolling and perforation according to claim 1, Features: In step six, the angle between the hypotenuse of the guide plate and the bottom plane is 56°-63°, the entrance cone angle is 5.3°-5.6°, the entrance section curvature is R107mm-R112mm, the top curvature is R106mm-R111mm, the exit cone angle is 2.3°-2.7°, the exit curvature is R215mm-R211mm, the bottom cone angle is 130°-133°, the length from the bottom cone of the guide plate to the working surface is 80mm-85mm, the entrance section width is 125mm-127mm, the exit section width is 167mm-172mm, the total length of the guide plate is 558mm-663mm, the bite section length is 207mm-212mm, and the ejection section length is 348mm-353mm.

8. The method for producing a super austenitic seamless steel pipe by oblique rolling and perforation according to claim 1, Features: In step seven, the rolling rollers are designed as tapered rollers, with an inlet cone angle of 2.6°-2.9°, an outlet cone angle of 2.9°-3.2°, a roller surface length of 745mm-751mm, an inlet working surface length of 306mm-308mm, and a working rolling center roller diameter of 992mm-1013mm.

9. The method for producing a super austenitic seamless steel pipe by oblique rolling and perforation according to claim 1, Features: In step eight, the roller spacing is 131.4mm-132.2mm, the guide plate spacing is 147.5mm-149mm, and the top head extension is 64mm-66mm.

10. The method for producing a super austenitic seamless steel pipe by oblique rolling and perforation according to claim 1, Features: In step nine, the circulating water temperature does not exceed 50°C.

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