CN113814287B

CN113814287B - Precise warm extrusion forming method for steel anchoring flange and steel anchoring flange

Info

Publication number: CN113814287B
Application number: CN202111182909.XA
Authority: CN
Inventors: 聂杨峻峰; 王思琪; 任贤魏; 赵熹; 张治民
Original assignee: North University of China
Current assignee: North University of China
Priority date: 2021-10-11
Filing date: 2021-10-11
Publication date: 2023-07-28
Anticipated expiration: 2041-10-11
Also published as: CN113814287A

Abstract

The invention relates to a precise warm extrusion forming method of a steel anchoring flange and the steel anchoring flange, belonging to the technical field of steel extrusion forming, and mainly adopting the following technical scheme: a precise warm extrusion forming method of a steel anchoring flange comprises the following steps: extruding and forming the blank obtained after the blank forging to obtain a steel anchoring flange formed part; wherein the temperature of the extrusion forming treatment is 950-980 ℃. And extruding and forming the blank obtained after cogging and forging by adopting a precision extrusion forming die of the anchoring flange. The extrusion forming process comprises a first compression molding step, a second compression molding step, a first punching step and a second punching step. The invention is mainly used for improving the performance of the steel anchoring flange, improving the dimensional accuracy of the steel anchoring flange forming part and reducing the production energy consumption of the steel anchoring flange, thereby saving energy.

Description

Precise warm extrusion forming method for steel anchoring flange and steel anchoring flange

Technical Field

The invention relates to the technical field of steel extrusion forming, in particular to a precise warm extrusion forming method of a steel anchoring flange and the steel anchoring flange.

Background

The anchoring flange is a key device which is arranged for preventing the axial thrust from damaging the valve chambers of each station in large-caliber, high-pressure and long-distance oil-gas pipeline engineering, is arranged at the soil inlet end and the soil outlet end of the pipeline, plays roles of fixing the pipeline, restraining the axial displacement of the pipeline, protecting the ground pipeline and equipment in the station and the like, and plays a decisive role in guaranteeing the safety and the reliability of natural gas transportation. The long oil and gas pipeline has the characteristics of large pipe diameter and high pressure delivery, and the anchoring flange is required to have high internal high pressure bearing capacity; in order to protect the pipeline, so that the pipeline keeps good integrity, is not easy to break or deform under pressure impact under the field low-temperature condition, and is required to have good welding performance and very high low-temperature toughness between the anchoring flange and the pipeline.

At present, the production process of domestic anchor flange forging mainly comprises the following steps: cogging forging-die forging-ring rolling-rough machining-heat treatment-finish machining; wherein extrusion (e.g., swaging) is performed at high temperatures (1150-1200 c).

However, the anchor flange forming member is produced by adopting a high-temperature extrusion forming process, and at least the following technical problems exist: (1) The high temperature extrusion forming can cause coarse grain size in the formed piece, so that the performance of the finally obtained anchoring flange is poor; (2) the energy consumption of the high-temperature extrusion forming process is high; (3) After high-temperature extrusion forming, the extrusion forming piece can retract, and the shrinkage rate is higher, so that the dimensional accuracy of the anchoring flange forming piece is low.

Disclosure of Invention

In view of the above, the present invention provides a method for forming a steel anchoring flange by precision warm extrusion and a steel anchoring flange, which mainly aims to improve the performance of the steel anchoring flange and reduce the energy consumption for producing the steel anchoring flange.

In order to achieve the above purpose, the present invention mainly provides the following technical solutions:

in one aspect, embodiments of the present invention provide a precision warm extrusion method for a steel anchor flange, comprising the steps of: extruding and forming the blank obtained after the blank forging to obtain a steel anchoring flange formed part; wherein the temperature of the extrusion forming treatment is 950-980 ℃; wherein the average grain size of the blank obtained after the cogging forging is 30-40.5 mu m.

Preferably, a precision extrusion forming die of the anchor flange is adopted to carry out extrusion forming treatment on the blank obtained after the cogging forging; wherein the step of extrusion processing includes:

a first-time profiling step: matching the first profiling male die structure and the female die into a first profiling die, and performing primary profiling on the blank obtained after the blank is opened and forged to obtain a blank after primary profiling;

and a second pressing step: matching the second profiling male die structure and the female die into a second profiling die, and performing second profiling treatment on the blank after the first profiling to obtain an anchoring flange blank;

A first punching step: matching the first punching male die structure and the female die into a first punching die, and punching the anchoring flange blank to obtain an anchoring flange blank with punching holes;

a second punching step: and matching the second punching male die structure and the female die into a second punching die, further punching the anchor flange blank with the punched holes, and punching through the punched holes to obtain the steel anchor flange forming piece.

Preferably, in the step of the extrusion molding treatment, the extrusion speed is 1 to 3mm/s.

Preferably, before the first profiling step, the method further comprises: heating the blank obtained after cogging forging to a first set temperature and preserving heat, wherein the first set temperature is the extrusion forming treatment temperature; preheating a precision extrusion forming die of the anchoring flange to a second set temperature and preserving heat; wherein the second set temperature is 400-450 ℃.

In the first profiling step:

the blank after the first primary compression comprises a flange and a truncated cone-shaped first neck part positioned at one side of the flange; wherein the radial dimension of the flange on the blank after the first press forming is smaller than the radial dimension of the flange of the required steel anchor flange forming member; the longitudinal dimension of the flange of the blank after the first press forming is larger than that of the flange of the required steel anchoring flange forming piece;

Preferably, the size of the first neck part on the blank after the first press molding is matched with the part above the backing plate in the round table-shaped cavity of the female die;

preferably, the first-time profiling step includes:

discharging: one end of the blank obtained after cogging forging is arranged on a backing plate in a round table-shaped cavity of the female die, and the other end of the blank obtained after cogging forging is positioned in a cylindrical cavity of the female die; the blank obtained after cogging forging is a cylindrical blank, and the diameter of the cylindrical blank is smaller than the inner diameter of the large end of the truncated cone-shaped cavity of the female die;

first press molding: pressing a first punch press block in a first profiling punch structure into a cylindrical cavity of the female die, and placing the first punch press block on a blank obtained after cogging forging; and controlling the first press-forming male die structure to descend, and performing first press-forming treatment on the blank obtained after cogging forging to obtain the blank after first press-forming.

In the second press-forming step:

the anchoring flange blank comprises a flange, a first neck in a truncated cone shape and a second neck in a truncated cone shape; wherein the first neck is located on one side of the flange and the second neck is located on the other side of the flange; the radial dimension of the flange of the anchoring flange blank is larger than that of the flange on the blank after the first-time compression; the longitudinal dimension of the flange of the anchoring flange blank is smaller than the longitudinal dimension of the flange on the blank after the first-time compression; preferably, the dimensions of the second neck portion on the anchoring flange blank are adapted to the dimensions at the large end of the first neck portion.

Preferably, the second press molding step includes:

pressing a second punch press block in a second profiling punch structure into a cylindrical cavity of the female die and placing the second punch press block on the blank after the first profiling; controlling the second press-forming male die structure to descend, and performing second press-forming treatment on the blank after the first press-forming to obtain an anchoring flange blank;

the compression end of the second male die pressing block is provided with a round table-shaped cavity, and a large end opening of the round table-shaped cavity is positioned at the end part of the compression end; the other parts of the end parts of the profiling ends of the second punch press blocks form profiling steps relative to the large end opening of the round table-shaped cavity; when the second male die pressing block is arranged on the blank after the first pressing, a pressing step on the second male die pressing block is opposite to the step structure of the female die, and a round table-shaped cavity on the second male die pressing block is opposite to the round table-shaped cavity of the female die; preferably, the size of the truncated cone-shaped inner cavity on the second punch press block is matched with the size of the cavity at the large end of the truncated cone-shaped cavity of the female die;

preferably, the size of the first neck part of the anchoring flange blank is matched with the part above the backing plate in the truncated cone-shaped cavity of the female die; the size of the second neck part of the anchoring flange blank is matched with the size of the truncated cone-shaped cavity on the second punch pressing block; the periphery of the flange of the anchoring flange blank is contacted with the inner wall of the cylindrical cavity of the female die.

Preferably, in the first punching step:

the anchoring flange blank obtained after the second profiling is turned over by 180 degrees and then placed in the cavity of the female die, so that the outer limit of the anchoring flange blank is realized; a limiting block in the first punching male die structure, which is sleeved on a punching punch, is pressed into a cylindrical cavity of a female die from the inlet end of the female die, a limiting cavity matched with the shape of a required steel anchoring flange forming part is limited by the female die, and the limiting block can guide the punching punch and limit the shaking of the punching punch in the punching process, so that the internal limiting of an anchoring flange blank is realized;

preferably, after the anchoring flange blank after the second profiling is placed in the cavity of the female die, a second neck of the anchoring flange blank is placed in the truncated cone-shaped cavity of the female die, and a gap exists between the anchoring flange blank and a backing plate in the female die; after the limiting block is pressed into the cavity of the female die, the anchoring flange blank is limited: the first neck of the anchoring flange blank is positioned in the truncated cone-shaped limiting cavity of the limiting block, and a gap is formed between the first neck and the inner wall of the truncated cone-shaped limiting cavity of the limiting block;

preferably, in the punching process, after the male die insert on the punching punch contacts with the limiting block, the male die insert drives the limiting block to move downwards along with the punching punch, and acting force is applied to the punched opening of the anchor flange blank with the punched hole, so that the shaping of the opening is completed; wherein the male die insert is positioned on one end of the punching punch opposite to the punch end;

Preferably, after the first punching is finished, the punching punch is moved upwards, and the limiting block is taken out of the female die through a working belt on the punch end of the punching punch.

Preferably, the second punching step includes: after the anchor flange blank with the punched hole is taken out of the female die, the punching ring is arranged in a cavity of the female die; placing an anchoring flange blank with punching holes in a cavity of the female die and positioning the anchoring flange blank on the punching ring; and (3) carrying out secondary punching on the anchoring flange blank with the punched hole by adopting a profiling punch with a second punching punch structure so as to punch the punched hole through, thereby obtaining the steel anchoring flange forming piece.

Preferably, the blank obtained after cogging forging is made of CF-62 microalloyed steel.

Preferably, before the step of extrusion forming the blank obtained after the cogging forging, cogging forging is further included on a steel anchor flange blank to prepare the blank obtained after the cogging forging; wherein the average grain size of the steel anchoring flange blank is 56.9-70 mu m; the true strain of the cogging forging is greater than 1.8.

In another aspect, an embodiment of the present invention provides a steel anchoring flange, where the steel anchoring flange formed part is a steel anchoring flange formed part obtained by the precision warm extrusion forming method of the steel anchoring flange described in any one of the above;

Preferably, the steel anchor flange has an average grain size of 7-9 μm;

preferably, the tensile strength of the steel anchoring flange is more than or equal to 630MPa; the yield strength of the steel anchoring flange is more than or equal to 520MPa; the yield ratio of the steel anchoring flange is less than or equal to 0.84; the elongation rate of the steel anchoring flange is more than or equal to 25%;

preferably, the steel anchoring flange is made of CF-62 microalloyed steel;

preferably, the heat treatment process is that the steel anchoring flange forming piece is subjected to first heat treatment at 870-940 ℃, water cooling is carried out, the steel anchoring flange forming piece after the first heat treatment is subjected to second heat treatment at 600-660 ℃, and air cooling is carried out, so that the steel anchoring flange is obtained.

Compared with the prior art, the precise warm extrusion forming method of the steel anchoring flange and the steel anchoring flange have at least the following beneficial effects:

the embodiment of the invention provides a precise warm extrusion forming method of a steel anchoring flange, which firstly provides a warm extrusion forming method for extrusion forming of a steel anchoring flange formed part, namely the temperature of extrusion forming treatment of a blank obtained after blank opening forging is reduced (specifically, the temperature is reduced to a medium temperature of 950-980 ℃ from the high temperature of 1150-1200 ℃ in the prior art), and the temperature of extrusion forming treatment is reduced, so that at least the following three effects can be realized: (1) The production energy consumption of the steel anchoring flange forming piece can be reduced, so that the energy is saved; (2) The warm extrusion forming can ensure that the grains in the material are small and precipitated phases are dispersed, thereby greatly improving the performance of the steel anchoring flange; (3) The steel anchoring flange piece after warm extrusion forming has high dimensional accuracy, and precise extrusion forming is realized.

Further, the embodiment of the invention adopts the precise extrusion forming die of the anchoring flange to carry out warm extrusion forming on the blank obtained after the blank is formed by forging, so that the wall thickness difference of the steel anchoring flange forming part can be reduced (the precision of extrusion forming is further improved), labor-saving forming is realized, and the problem that the mouth part of the forming part collapses in the conventional blank die forging free punching is solved.

In summary, the precision warm extrusion forming method of the steel anchoring flange improves the dimensional precision of an extrusion forming piece, effectively regulates and controls the material tissue morphology, refines grains, and can greatly improve the performance of the steel anchoring flange; further, the wall thickness difference of the steel anchoring flange forming piece can be reduced, the corner collapse of the opening of the forming piece is avoided, the material utilization rate is improved from 47.4% to 65%, the production efficiency and the yield are improved, the energy consumption and the pollution emission are reduced, the production procedures of the steel anchoring flange forming piece are effectively reduced, the comprehensive cost is reduced, the pollution emission is reduced, and the product performance consistency is ensured.

The foregoing description is only an overview of the present invention, and is intended to provide a better understanding of the present invention, as it is embodied in the following description, with reference to the preferred embodiments of the present invention and the accompanying drawings.

Drawings

FIG. 1 is an assembly schematic of a first profiling die provided in an embodiment of the present invention;

FIG. 2 is an assembly schematic of a second profiling mold provided in an embodiment of the present invention;

fig. 3 is an assembly schematic diagram of a first punching die provided in an embodiment of the present invention;

fig. 4 is an assembly schematic diagram of a second punching die provided in an embodiment of the present invention;

FIG. 5 is a flow chart of a precision warm extrusion method for forming a steel anchor flange according to an embodiment of the present invention;

fig. 6 is an assembly schematic diagram of a first piercing punch structure and a second die plate according to an embodiment of the present invention;

fig. 7 is a schematic connection diagram of a punching punch and a limiting block in a first punching punch structure according to an embodiment of the present invention;

FIG. 8 is a partial schematic view of the structure of FIG. 6;

FIG. 9 is a partial schematic view of a punch head provided in an embodiment of the present invention;

FIG. 10 is a schematic diagram of a stopper according to an embodiment of the present invention;

FIG. 11 is a microstructure view of a steel anchor flange blank;

FIG. 12 is a microstructure view of a blank obtained after cogging forging;

FIG. 13 is a microstructure view of a steel anchor flange;

FIG. 14 is a heat treatment process diagram;

fig. 15 is a graph comparing the effect of a steel anchor flange formed article obtained by a conventional free punching method with that of the embodiment of the present invention using a precision press forming die.

Detailed Description

In order to further describe the technical means and effects adopted for achieving the preset aim of the invention, the following detailed description refers to the specific implementation, structure, characteristics and effects according to the application of the invention with reference to the accompanying drawings and preferred embodiments. In the following description, different "an embodiment" or "an embodiment" do not necessarily refer to the same embodiment. Furthermore, the particular features, structures, or characteristics of one or more embodiments may be combined in any suitable manner.

Example 1

The embodiment provides a precise warm extrusion forming method of a steel anchoring flange, as shown in fig. 5, comprising the following steps: extrusion-forming the blank 31 obtained after the blank forging to obtain a steel anchor flange formed part 35; wherein the temperature of extrusion forming treatment is 950-980 ℃; wherein the average grain size of the blank 31 obtained after the cogging forging is 30 to 40.5 μm.

The embodiment proposes that a warm extrusion forming method is adopted for extrusion forming of a steel-making anchoring flange forming piece for the first time, namely, the temperature of extrusion forming treatment of a blank 31 obtained after blank forging is reduced; (specifically, the high temperature of 1150-1200 ℃ in the prior art is reduced to the medium temperature of 950-980 ℃) and the extrusion forming temperature is reduced, at least three effects can be achieved: the production energy consumption of the steel anchoring flange forming piece can be reduced, so that the energy is saved; the warm extrusion forming can ensure that the grains in the material are small and precipitated phases are dispersed, thereby greatly improving the performance of the steel anchoring flange; the steel anchoring flange piece after warm extrusion forming has high dimensional accuracy, and precise extrusion forming is realized.

What should be stated here is: the precondition for realizing warm extrusion molding is that the grains of the billet are thinned and the plasticity of the billet itself is improved (metal fluidity is good) by cogging forging (i.e., repeated upsetting and drawing processes), and specifically, the performance of the billet obtained after cogging forging satisfies the above conditions (i.e., the average grain size of the billet obtained after cogging forging is 30 to 40.5 μm), thereby providing a possibility for extrusion molding at a reduced temperature.

The precise warm extrusion molding method for the steel anchor flange provided in the embodiment 1 can be applied to the steel anchor flange mold in the prior art.

Preferably, before the step of extrusion forming the blank obtained after the cogging forging, the method further comprises the step of cogging forging the steel anchor flange blank to prepare the blank obtained after the cogging forging; wherein, the structure of the steel anchoring flange blank is austenite and pearlite, and the average grain size is 56.9-70 mu m; the true strain of the cogging forging is greater than 1.8. After cogging forging (large deformation cogging), the crystal grains are refined, the crystal grain size is reduced to 30-40.5 mu m, brittle carbides and internal segregation tissues in the steel are broken, and the subsequent plastic deformation capacity of the material is improved due to the grain refinement and the breaking of the carbides.

Example 2

Preferably, in this embodiment, in order to further improve the dimensional precision (reduce the wall thickness difference) of the steel anchor flange forming member and improve the utilization rate of materials based on embodiment 1, it is proposed to use a precision extrusion forming die for the anchor flange to perform extrusion forming treatment on the blank obtained after the cogging forging. Here, the structural features of the precision extrusion molding die for the anchor flange are mainly described in detail in this embodiment, and specifically as follows:

as shown in fig. 1-10, the anchor precision extrusion die includes a first die assembly and a second die assembly; wherein the first mold assembly comprises a female mold 12; the second mold assembly includes: a first punch structure (for cooperation with the female die 12 to form a first punch die for punching the anchor flange blank 33); preferably, the second die further comprises a second punch structure (for further punching the punched anchor flange blank 34 obtained after punching the first punch die to punch through the punched hole). Preferably, the second die further comprises a first profiling punch structure (for cooperation with a female die into a first profiling die), a second profiling punch structure (for cooperation with a female die into a second profiling die) for profiling the blank 31 obtained after cogging forging into an anchoring flange blank 33 to be punched.

In addition, the first mold assembly further includes a first mold plate 11 for connecting to a press (specifically, the first mold plate 11 is for connecting to a lower structure of the press); wherein the female die 12 is fixed on the first die plate 11. The second mould assembly further comprises a second mould plate 21 for connection to a press (in particular, the second mould plate is for connection to a superstructure of a press). The first punching punch structure, the second punching punch structure, the first profiling punch structure and the second profiling punch structure mentioned above are used for being fixed on the second template 21 when being matched with the female die 12.

On the one hand, in this embodiment, the first punching male die structure, the structure of the female die 12 and the cooperation thereof are described as follows: first punch structure (here, the first punch structure is referred to as an M-shaped combined punch structure fixed to the second die plate 21 shown in fig. 6). Wherein, this first punch male die structure is used for forming first cut-out press with die 12 cooperation, is used for punching out anchor flange blank 33. Wherein the first punching male die structure comprises a punching punch 231 and a limiting block 232; the limiting block 232 is sleeved on the punching punch 231 to guide the punching punch 231 and limit the punching punch 231 from shaking in the punching process. Wherein, during punching, the limiting block 232 is used for being pressed into the cavity of the female die 12, and the female die 12 limits a limiting cavity (preferably, the limiting cavity is a closed cavity) which is matched with the external dimension of the required steel anchoring flange forming piece, and simultaneously limits the anchoring flange blank 33 internally and externally (here, simultaneous internal and external limiting is explained as follows: for the blank, the female die in the limiting cavity can restrict the blank, then an external limiting is formed, and the limiting block can restrict the punch, so that the punch cannot deviate in the punching process, then an internal limiting is formed). Through the above arrangement, in the whole punching process, the movement of the anchor flange blank 33 can be limited by the cooperation of the limiting block 232 and the female die 12 (i.e. the anchor flange blank 33 is fixed), the shaking of the punching punch 231 is limited by the limiting block 232, so that the punching punch 231 can directly punch the anchor flange blank 33, and further the wall thickness difference of the extruded steel anchor flange forming piece 35 is reduced, and the utilization rate of materials can be further improved.

Preferably, as shown in fig. 1 to 5, the die 12 is designed as follows: the cavity of the female die 12 includes a cylindrical cavity, a truncated cone-shaped cavity (i.e., a truncated cone-shaped cavity), and a pad 121. The cylindrical cavity is provided with a first end and a second end which are oppositely arranged; wherein the first end of the cylindrical cavity is open and serves as the inlet end of the die 12. The large end of the round table-shaped cavity is directly communicated with the second end of the cylindrical cavity, and the inner diameter of the large end of the round table-shaped cavity is smaller than that of the cylindrical cavity, so that a step structure is formed at the communication part of the cylindrical cavity and the round table-shaped cavity (namely, the cavity of the female die is of a step-shaped through hole structure). The cushion block 121 is adapted to the small end of the truncated cone-shaped cavity and is arranged at the small end of the truncated cone-shaped cavity. Preferably, the small end opening of the round table-shaped cavity is arranged at the end part of the fixed end of the female die. The end part of the fixed end of the female die is fixed on the first template 11, the first template 11 is provided with a push rod mounting hole, and the push rod mounting hole corresponds to the small end opening of the round table-shaped cavity. The first mold assembly further includes a ram 111; the top end of the ejector rod 111 is internally arranged in the ejector rod mounting hole of the first template; further preferably, the axis of the ejector rod 111 and the axis of the ejector rod mounting hole are positioned on the same straight line; the device is arranged to realize demoulding and unloading by the upward movement of the ejector rod.

Preferably, as shown in fig. 1 to 7 and 10, based on the structure of the female die 12, the structure of the stopper 232 in the first punching male die structure (M-shaped combined male die structure) is further designed: the stopper 232 has a first end (the lower end of the stopper 232 shown in fig. 10), and a truncated cone-shaped stopper cavity 2321 (i.e., a truncated cone-shaped stopper cavity) is provided on the first end of the stopper 232; wherein, the big end of round platform form spacing cavity 2321 is opened and is set up, and round platform form spacing cavity 2321's big end department is opened and is located the first end tip of stopper 232 for the other part of the first end tip of stopper 232 forms spacing step for round platform form spacing cavity 2321. After the limiting block 232 is pressed into the cylindrical cavity from the inlet end of the die 12: the limiting step of the limiting block 232 is arranged opposite to the step structure in the cavity of the die 12 so as to limit the flange of the anchoring flange blank 33 (the periphery of the flange of the anchoring flange blank is in abutting contact with the inner wall of the cylindrical cavity, one side of the flange of the anchoring flange blank is arranged on the step structure of the die, and the limiting step of the limiting block is in abutting contact with the other side of the flange of the anchoring flange blank); the truncated cone-shaped limiting cavity 2321 of the limiting block 232 is arranged opposite to the truncated cone-shaped cavity of the female die 12, so as to limit two necks of the anchoring flange blank 33 respectively.

Preferably, the cone angle of the truncated cone-shaped limiting cavity on the limiting block 232 is larger than that of the truncated cone-shaped cavity in the female die 12; the depth of the truncated cone-shaped limiting cavity 2321 is greater (slightly greater) than the distance between the large end port of the truncated cone-shaped cavity and the backing plate 121; the inner diameter of the large-end opening of the circular-table-shaped limiting cavity 2321 is larger (slightly larger) than the inner diameter of the large-end opening of the circular-table-shaped cavity of the female die 12. The above arrangement is to enable the upper neck of the anchoring flange blank to be accommodated in the truncated cone-shaped limiting cavity 2321, and a hole is reserved between the upper neck and the inner wall of the truncated cone-shaped limiting cavity.

Preferably, the outer peripheral dimension of the limiting block 232 is adapted to the dimension of the cylindrical cavity of the female die 12, so that the limiting block 232 is pressed into the cylindrical cavity of the female die 12 from the inlet end of the female die 12 and then is in abutting contact with the cavity wall of the cylindrical cavity of the female die 12; further preferably, the outer peripheral dimension of the stopper 232 is larger than the diameter of the cylindrical cavity (here, the outer peripheral dimension is slightly larger than the diameter of the cylindrical cavity, so that the stopper 232 can enter the cylindrical cavity and the stopper 232 can limit the anchoring flange blank 33); the inlet end of the female die 12 (the mouth of the female die) is provided with a chamfer, so that the limiting block 232 can be pressed into the cylindrical cavity of the female die 12.

What should be stated here is: the cavity of the female die 12 is arranged into a cylindrical cavity and a circular truncated cone-shaped cavity structure which are communicated, and a step structure is formed at the communication part of the cylindrical cavity and the large end of the circular truncated cone-shaped cavity; meanwhile, a round table-shaped limiting cavity is arranged at the first end of the limiting block 232, the large end of the round table-shaped limiting cavity is open, and the opening is positioned at the first end part of the limiting block 232, so that other parts of the first end part of the limiting block 232 form a limiting step relative to the round table-shaped limiting cavity; the arrangement ensures that the limiting block 232 can limit the limiting cavity matched with the external dimension of the required steel anchoring flange forming piece with the cavity of the female die 12 after being pressed into the cylindrical cavity of the female die 12; in addition, one neck (lower neck) of the anchoring flange blank 33 is constrained by the round table-shaped cavity of the female die 12, so that the outer limit of the anchoring flange blank 33 is realized, the limiting block 232 is limited by the female die 12 and cannot move left and right, and the limiting block 232 can also constrain the punch, so that the punch cannot deviate, and the inner limit of the anchoring flange blank is realized; therefore, the female die 12 and the limiting block 232 with the above structure can limit the anchoring flange blank simultaneously inside and outside.

Preferably, as shown in fig. 1 to 10, the structure of the stopper 232 and the punch 231 in the first punch structure (M-shaped combined punch structure) and the connection manner of the two are further designed as follows: the limiting block 232 has a second end (an upper end of the limiting block shown in fig. 10), and the second end of the limiting block 232 is opposite to the first end of the limiting block 232; the second end of the limiting block 232 is provided with a through hole 2322, which is used for enabling the limiting block 232 to be sleeved on the punching punch 231 so as to guide the punching punch 231 and limit shaking of the punching punch 231; the through hole 2322 is communicated with the circular truncated cone-shaped limiting cavity 2321, the through hole 2322 is matched with the outer circumferential dimension of the cylinder of the punching punch 231, and the inner diameter of the through hole 2322 is smaller than the inner diameter of the small end of the circular truncated cone-shaped limiting cavity 2321.

Preferably, the head of the punching punch 231 is provided with a working belt 2311; wherein, the diameter of the working belt 2311 is larger than the cylinder diameter of the punching punch 231, and the diameter of the working belt 2311 is smaller than the inner diameter of the small end of the circular-table-shaped limiting cavity 2321 (so that the working belt 2311 can pass through the circular-table-shaped limiting cavity in the punching direction and cannot enter the through hole in the direction opposite to the punching direction). Specifically, a circle of accommodating cavity 2323 is formed at the intersection of the hole wall of the through hole 2322 and the end part of the small end of the circular truncated cone-shaped limiting cavity 2321 so as to accommodate the working belt 2311 of the punching punch 231, wherein one end of the accommodating cavity 2323 is communicated with the through hole 2322, and the other end of the accommodating cavity 2323 is communicated with the circular truncated cone-shaped limiting cavity 2321. With the above arrangement, not only the forming load and the drawing force can be reduced, but also the punch 231 can lift the stopper 232 after the punching is completed.

Regarding the structural features of the stopper 232, and in conjunction with the drawings, it can be seen that the stopper 232 is an M-shaped stopper.

Here, in this embodiment, through the through hole 2322 that communicates with the circular truncated cone-shaped limiting cavity and is adapted to the outer circumferential dimension of the cylinder of the punching punch 231 is formed on the limiting block 232, so that the limiting block 232 is sleeved on the punching punch 231, and the guiding of the punching punch 231 is achieved through the through hole 2322 on the limiting block, and the shaking of the punching punch 231 is limited. Further, in this embodiment, the working belt 2311 is disposed at the head of the punching punch 231, and the accommodating cavity 2323 is disposed at the intersection of the through hole wall of the limiting block 232 and the small end of the circular truncated cone-shaped limiting cavity, so that the working belt 2311 for accommodating the punching punch 231 is disposed, on one hand, the forming load and the die drawing force are reduced, and on the other hand, the limiting block 232 can be lifted after the punching is finished.

Preferably, as shown in fig. 3 and 5, the first punching die is further designed as follows: when the limiting block 232 is pressed into the cavity of the female die 12 and the female die 12 is limited to a limiting cavity matched with the external dimension of the required steel anchoring flange forming piece, the limiting cavity is formed by the following steps: the cavity wall of the limit cavity is abutted against the flange of the anchoring flange blank 33, a gap is reserved between the whole first neck (upper neck) of the anchoring flange blank 33 and the cavity wall of the limit cavity, and a gap is reserved between the end part of the small end of the second neck (lower neck) and the cavity wall of the limit cavity. Specifically, when punching, the first neck (upper neck) of the anchoring flange blank 33 is accommodated in the truncated cone-shaped limiting cavity on the limiting block 232, and a gap is reserved between the whole first neck and the cavity wall of the truncated cone-shaped limiting cavity on the limiting block 232; the second neck (lower neck) is attached to the side wall of the truncated cone-shaped cavity of the female die 12; a gap is left between the small end of the second neck and the backing plate 121 in the round table-shaped cavity of the female die 12. The upper side of the flange of the anchoring flange blank 33 is tightly attached to the limit step of the limit block 232, and the lower side of the flange of the anchoring flange blank 33 is tightly attached to the step structure of the female die 12.

Here, in the present embodiment, after the stopper and the female die limit the anchoring flange blank 33, the second neck (lower neck) of the anchoring flange blank 33 is suspended in the truncated cone-shaped cavity of the female die 12, and a gap is left between the first neck (upper neck) of the anchoring flange blank 33 and the stopper 232; in the process of punching, the metal flows in the upper direction and the lower direction simultaneously, and short-range flow is controlled, so that compared with the traditional back extrusion, the metal flow path is reduced, and the labor-saving forming effect is achieved; and labor-saving forming can reduce energy consumption and prolong the service life of the die.

It should be noted that: due to the flow of metal in the punching process, when the punching reaches a preset position, the shape of the anchor flange blank with the punching is matched with the size of the limit cavity, namely, no gap exists between the anchor flange blank with the punching, the limit block and the female die.

Preferably, as shown in fig. 3, 5, 6 and 8, the present embodiment further designs the first piercing punch structure as follows: the first piercing punch structure further includes a punch insert 233; wherein the punching punch 231 has a first end (lower end) and a second end (upper end) disposed opposite to each other; wherein the head of the punching punch 231 is located at a first end (lower end, punch end) of the punching punch, wherein the punch insert 233 is sleeved on a second end (upper end, fixed end) of the punching punch; wherein, during punching, the punch insert 233 descends along with the punching punch 231, and when the punch insert 233 descends to contact with the stopper 232 (see (e) diagram in fig. 5), the punch insert 233 drives the stopper 232 to descend together along with the continued descending of the punching punch 211, and the punch insert 233 and the stopper 232 together apply a force to the punched mouth (i.e., the upper mouth) of the anchor flange blank 34 having the punched hole.

Here, in this embodiment, the first punching punch structure includes the punch insert 233 sleeved on the second end (the end opposite to the head of the punching punch) of the punching punch 231, and the punch insert 233, along with the descending of the punching punch 231, applies a force to the punched mouth of the punched anchor flange blank 34 together with the stopper 232 when the punch insert 233 descends to contact with the stopper 232 in the punching process, so as to perform a shaping function, thereby ensuring the flush mouth of the extruded anchor flange formed part, solving the problem that the mouth of the formed part collapses in the conventional blank die forging free punching, and further improving the utilization rate of materials.

Preferably, the male die insert 233 has a first through hole and a second through hole which are communicated, and the inner diameter of the first through hole is larger than the inner diameter of the second through hole; wherein an end of the second end of the punching punch 231 is provided as a connecting portion; wherein, the size of the connecting part is matched with the first through hole and is arranged in the first through hole; the inner diameter of the second through hole is matched with the outer diameter of the cylinder body at the second end of the punching punch; by the above arrangement, the socket joint of the punch insert 233 and the second end of the punching punch 231 is achieved.

Preferably, the first piercing punch structure is connected to the second die plate 21 by a punch insert 233. Specifically, the first piercing punch structure further includes a punch retainer 234; wherein the punch retainer 234 crimp (compressively connects) the punch insert 233 to the platen 235; the punch retainer 234, the presser 235, and the second die plate 21 are fastened by fasteners (e.g., bolts).

The description above has been made regarding the die, the first punch structure, and the cooperation of both, as described above, the first punch structure is used to punch the anchor flange blank 33, but the punched hole is not punched, as in the (e) diagram of fig. 5, and the punched hole of the anchor flange blank 34 having the punched hole also has the bottom.

On the other hand, as shown in fig. 4 and 5, the second punch structure of the present embodiment is used to form a second punch die in cooperation with the female die 12, for further punching the anchor flange blank 34 with the punched hole obtained after punching by the first punch die to punch through the punched hole thereon (i.e., to punch out the remaining blank of the bottom thickness), to obtain the anchor flange-formed member 35. Specifically, the second piercing punch structure includes a profiling punch 221. Wherein the profiling punch 221 is adapted to be attached to the second die plate 21. Preferably, the second pierce die assembly also includes a pierce ring 122 for positioning within the cavity of the female die 12 during piercing and for supporting the portion to be pierced of the anchor flange blank 34 having the piercing. Specifically, prior to punching. The pierce ring 122 is placed on the spacer 121 in the frustoconical cavity of the female die 12, and the end of the lower neck portion of the anchor flange blank 34 with the pierced hole is placed on the pierce ring 122.

On the other hand, as shown in fig. 1 to 3 and 5, the first profiling punch structure, the second profiling punch structure, and the cooperation with the die 12 for profiling the anchor flange blank 33 to be punched with the die in the second die assembly in the present embodiment are specifically as follows:

the first profiling punch structure is used for forming a first profiling die in cooperation with the die 12, and is used for performing a first profiling treatment on a blank 31 (i.e. a cylindrical blank) obtained after cogging forging, wherein the first profiling punch structure comprises a profiling punch 221 and a first punch press 222; wherein the profiling punch 221 is used for connecting the second die plate 21; the first punch press 222 is a plate structure for applying pressure to the blank 31 obtained after the cogging forging placed in the die 12 by the press punch.

The second die assembly further comprises a second profiling male die structure, wherein the second profiling male die structure is used for being matched with the female die 12 to form a second profiling die, and is used for performing second profiling treatment on the blank 32 subjected to the first profiling to obtain an anchoring flange blank 33 to be punched for the first time; wherein the second profiling punch structure comprises a profiling punch 221 (the profiling punch 221 is used for connecting the second die plate 21) and a second punch press 223.

Wherein the second punch press 223 has a first end (press end) and a second end which are disposed opposite to each other; wherein, a first end of the second punch press 223 is provided with a round table-shaped cavity; wherein, the big end of the round platform-shaped cavity is open, and the big end opening of the round platform-shaped cavity on the second punch press 223 is located on the end of the first end of the second punch press 223, so that other parts on the end of the first end of the second punch press 223 form profiling steps relative to the round platform-shaped cavity. Wherein, when the second press forming is performed, the press forming punch 221 abuts against the end part of the second end of the second punch press 223, so that the second punch press 223 performs the second press forming on the blank 32 after the first press forming; in the second press molding process, the second punch press 223 is pressed into the die 12, and the press steps are opposite to the step structure of the die 12, and the truncated cone-shaped cavity on the second punch press 223 is opposite to the truncated cone-shaped cavity of the die 23.

Preferably, the size of the frustoconical cavity on the second punch press 223 is adapted to the cavity size at the large end of the frustoconical cavity of the female die 12 (i.e., the cone angles of both are the same, but the depth of the frustoconical cavity is less than the distance between the large end opening of the frustoconical cavity and the backing plate 121).

Example 3

In this embodiment, as shown in fig. 5, the step of warm extrusion forming the blank obtained after the cogging forging by using the precision extrusion forming die of the anchor flange is further described on the basis of embodiment 2, and mainly includes:

and (3) forming preparation: the billet 31 obtained after the cogging forging is heated to a first set temperature (i.e., 950-980 ℃) which is the temperature of the extrusion molding process, and kept warm; preheating an anchor flange precision extrusion forming die to a second set temperature and preserving heat; wherein the second set temperature is 400-450 ℃ to reduce deformation non-uniformity caused by heat exchange.

In addition, the first profiling punch structure and the female die are assembled on the press, fitted into a first profiling die (specifically, the first profiling punch structure is attached to the second die plate 21 and then assembled on the upper structure of the press), and a certain lubricant is applied along the working surfaces of the first punch press 222, the female die 12 and the pad 121.

A first-time profiling step: the first press punch structure and the female die 12 are combined into a first press die, and the blank 31 obtained after the cogging forging is subjected to a first press forming process to obtain a blank 32 after the first press forming. Preferably, the step comprises:

Discharging: one end of a blank 31 obtained after cogging forging is placed on a backing plate 121 in a round table-shaped cavity of the female die 12, and the other end of the blank 31 obtained after cogging forging is located in a cylindrical cavity of the female die 12; the billet 31 obtained after the cogging forging is a cylindrical billet, and the outer diameter of the billet 31 obtained after the cogging forging is smaller than the inner diameter of the large end of the truncated cone-shaped cavity of the die 12.

First press molding: pressing a first punch press 222 (a working surface of the first punch press is coated with a certain lubricant) in a first profiling punch structure into a cylindrical cavity of the female die 12, and placing the first punch press on a blank 31 obtained after cogging forging; controlling the first press-forming male die structure to descend, and performing first-time press-forming treatment on the blank 31 obtained after the blank forging to obtain a blank 32 after the first-time press forming;

wherein the blank 32 after the first press forming includes a flange and a truncated cone-shaped first neck portion (including only one neck portion) located at one side of the flange; wherein the radial dimension of the flange on the blank 32 after the first press forming is smaller than the radial dimension of the flange of the desired steel anchor flange forming member 35; the longitudinal dimension of the flange of the blank 32 after the first press is greater than the longitudinal dimension of the flange of the desired steel anchor flange former 35. Wherein the size of the first neck part on the blank 32 after the first press molding is matched with the part above the backing plate 121 in the round table-shaped cavity of the female die 12.

And a second pressing step: the second profiling punch structure and the female die 12 are matched into a second profiling die, and the blank 32 after the first profiling is subjected to a second profiling treatment to obtain an anchoring flange blank 33.

Specifically, in the second press-molding step: removing the first punch press 222; the second punch press 223 and the profiling punch 221 are matched into a second profiling punch structure, and the second punch press 223 (the working surface (the end of the profiling end) of the second punch press 223 is smeared with a certain lubricant) in the second profiling punch structure is pressed into the cylindrical cavity of the die 12 and placed on the blank 32 after the first profiling; the second press punch structure is controlled to move downwards, and the blank 32 after the first press is subjected to the first press treatment to obtain an anchoring flange blank 33.

When the second punch press 223 is placed on the blank 32 after the first press forming, the press step on the second punch press 223 is opposite to the step structure of the die 12, and the truncated cone-shaped cavity on the second punch press 223 is opposite to the truncated cone-shaped cavity of the die 12. The size of the truncated cone-shaped inner cavity on the second male die pressing block is matched with the size of the cavity at the large end of the truncated cone-shaped cavity of the female die.

Preferably, the anchoring flange blank 33 comprises a flange, a first neck portion in the shape of a truncated cone and a second neck portion in the shape of a truncated cone; wherein the first neck is positioned at one side of the flange, and the second neck is positioned at the other side of the flange; wherein the radial dimension of the flange of the anchoring flange blank 33 is larger than the radial dimension of the flange on the blank 32 after the first profiling; the longitudinal dimension of the flange of the anchor flange blank 33 is smaller than the longitudinal dimension of the flange on the blank 32 after the first profiling; preferably, the dimensions of the second neck portion on the anchoring flange blank 33 are adapted to the dimensions at the large end of the first neck portion.

Preferably, the first neck portion of the anchoring flange blank 33 is sized to fit over the pad 121 in the frustoconical cavity of the female die 12; the second neck of the anchor flange blank 33 is sized to fit the size of the frustoconical cavity on the second punch press 223; the outer periphery of the flange of the anchor flange blank 33 is in contact with the inner wall of the cylindrical cavity of the die 12.

A first punching step: the first punching male die structure and the female die 12 are matched into a first punching die, and the fixed flange blank 33 is punched to obtain an anchor flange blank 34 with punching.

In the first punching step: turning over the anchoring flange blank obtained after the second profiling for 180 degrees, and placing the anchoring flange blank in a cavity of a female die to realize outer limit of the anchoring flange blank 33; the limiting block 232 sleeved on the punching punch 231 in the first punching male die structure is pressed into the cylindrical cavity of the female die 12 from the inlet end of the female die 12, a limiting cavity matched with the shape of the required steel anchoring flange forming piece 35 is limited with the female die 12, and the limiting block 232 can guide the punching punch and limit the shaking of the punching punch in the punching process, so that the internal limiting of the anchoring flange blank 33 is realized. Thus, the punching punch 231 can directly punch the anchoring flange blank 33, and further the wall thickness difference of the extruded steel anchoring flange forming piece 35 is reduced, so that the dimensional accuracy of extrusion forming is improved, and the utilization rate of materials is improved.

Preferably, after the anchoring flange blank 33 obtained after the second pressing is placed in the cavity of the female die 12, the second neck part of the anchoring flange blank 33 is placed in the truncated cone-shaped cavity of the female die 12, and a gap exists between the second neck part and the backing plate 121 in the female die 12; after the stopper 232 is pressed into the cavity of the female die 12 to limit the anchoring flange blank 33: the first neck of the anchoring flange blank 33 is located in the truncated cone-shaped limiting cavity of the limiting block 232, and a gap is formed between the first neck of the anchoring flange blank and the inner wall of the truncated cone-shaped limiting cavity of the limiting block 232. In the punching process, the metal flows in the upper direction and the lower direction simultaneously, and short-range flow is controlled, so that compared with the traditional back extrusion, the metal flow path is reduced, and the labor-saving forming effect is achieved; and labor-saving forming can reduce energy consumption and prolong the service life of the die.

Preferably, the first punching step further comprises: in the punching process, after the male die insert 233 on one end of the punching punch 231, which is opposite to the punch end, is in contact with the limiting block 232, the male die insert 233 and the limiting block 232 are driven to move downwards together along with the descending of the punching punch 231, acting force is applied to the punched opening of the anchor flange blank with punching, so that metal flows towards the opening to finish shaping the opening, the opening of the extruded anchor flange formed part is flush, the problem that the formed part has a corner collapse in the opening of the formed part in the conventional blank free die forging and punching is solved, and the utilization rate of materials is further improved.

Preferably, after the first punching is completed, the punching punch 231 is moved upward, and the stopper 232 is carried out of the die 12 by the operating belt 2311 on the punch end of the punching punch 231.

Preferably, before the inner and outer limiting of the anchoring flange blank 33, it further comprises: the second profiling punch is removed, the second module 21 and the first punching punch structure (M-shaped combined punch) are assembled on the press, and a certain amount of lubricant is smeared along the working surfaces of the punching punch 231, the die 12, the spacer 121, the stopper 232.

In addition, the anchor flange blank 34 with the punched holes has a flange, a first neck portion on one side of the flange, a second neck portion on the other side of the flange; the size of the first neck is matched with the truncated cone-shaped limiting cavity of the limiting block 232, and the size of the second neck is matched with the part above the base plate 121 in the female die 12.

A second punching step: the second piercing punch structure and the female die 12 are combined into a second piercing die, the anchor flange blank 34 with the piercing holes is further pierced, and the piercing holes are pierced, so that the steel anchor flange formed part 35 is obtained.

The method comprises the following steps: after the anchor flange blank 34 with the punched hole is taken out of the female die, the punching ring 122 is placed in the cavity of the female die 12; placing the anchor flange blank 34 with the punched hole in the cavity of the female die 12 and on the punching ring 122; the second piercing punch 221 of the second piercing punch structure punches the pierced anchor flange blank 34 a second time to punch the pierced anchor flange blank through to obtain the steel anchor flange member 35.

Preferably, the steps specifically include: removing the first punching male die structure, removing the anchoring flange blank 34 with the punching, placing the punching ring 122 in the cavity of the female die 12, smearing a certain lubricant along the working surfaces of the profiling punch 221, the female die 12 and the punching ring 122, placing the anchoring flange blank 34 with the punching in the cavity of the female die 12, punching the residual bottom thick blank by a press downwards, completing the preparation of the anchoring flange forming part, lifting the ejector rod, and removing the steel anchoring flange forming part 35.

In addition, in the step of the extrusion molding process described above, the extrusion speed is 1 to 3mm/s, and a slower extrusion speed is adopted to reduce the molding force.

To sum up: the precise warm extrusion forming method of the steel anchoring flange provided by the embodiment of the invention mainly adopts a warm extrusion forming method (namely, compared with the high-temperature extrusion forming in the prior art, the temperature of die forging is reduced), thereby improving the performance of the steel anchoring flange, improving the dimensional precision of an anchoring flange forming piece and reducing the production energy consumption of the anchoring flange. On the basis, the embodiment of the invention further adopts a precise extrusion forming die of the steel anchoring flange to carry out warm extrusion forming; therefore, the wall thickness difference of the steel anchoring flange forming piece can be reduced (the precision of extrusion forming is further improved), labor-saving forming is realized, and the problem that the mouth part of the forming piece collapses in the conventional blank die forging free punching is solved.

In conclusion, the precision warm extrusion forming method of the steel anchoring flange improves the extrusion forming precision, effectively regulates and controls the material tissue morphology, refines grains and greatly improves the performance; further, the wall thickness difference of the steel anchoring flange forming part is reduced, the corner collapse of the mouth part is avoided, the material utilization rate is improved from 47.4% to 65%, the production efficiency and the yield are improved, the energy consumption and the pollution emission are reduced, the production procedures of the steel anchoring flange forming part are effectively reduced, the comprehensive cost is reduced, the pollution emission is reduced, and the product performance consistency is ensured.

In addition, the steel anchor flange formed by the precision warm extrusion forming method of the steel anchor flange is subjected to heat treatment to obtain the steel anchor flange. Wherein the heat treatment process is shown in fig. 14; specifically, the heat treatment process comprises the following steps: and (3) performing primary heat treatment (preferably, the primary heat treatment time is 3 h) on the steel anchor flange forming piece at 870-940 ℃, performing secondary heat treatment (preferably, the secondary heat treatment time is 4 h) on the steel anchor flange forming piece after the primary heat treatment at 600-660 ℃ after water cooling, and air cooling to obtain the steel anchor flange.

Preferably, the steel anchoring flange forming member and the steel anchoring flange provided by the embodiment of the invention are made of CF-62 modified special steel (namely CF-62 microalloyed steel), and the chemical composition (%) is as follows:

c:0.07-0.09; mn:1.15-1.3; si:0.05-0.2; p: less than or equal to 0.025; s: less than or equal to 0.015; mo:0.2-0.3; v:0.05-0.08; nb:0.02-0.05; as: less than or equal to 0.02; pb: less than or equal to 0.01; sb is less than or equal to 0.01; sn: less than or equal to 0.012; bi: less than or equal to 0.01. Injecting gas content: h is less than or equal to 3ppm, O is less than or equal to 50ppm, and N is less than or equal to 80ppm.

The following is a further detailed description of specific experimental examples:

experimental example 1

As shown in fig. 5, in this experimental example, a steel anchor flange formed article was extrusion-formed by using the precision extrusion method for steel anchor flange provided in example 3, and then the steel anchor flange formed article was further heat-treated to prepare a steel anchor flange (the material was the above-mentioned CF-62 modified steel). The method mainly comprises the following steps:

cogging forging: the steel anchor flange blank is subjected to cogging forging to obtain a blank 31 obtained after cogging forging.

Wherein a microstructure view of a steel anchor flange blank is shown in fig. 11. A microstructure diagram of the blank obtained after the cogging forging is shown in fig. 12. The original structure of the steel anchoring flange blank is austenite and pearlite, the true strain of the forging cogging is larger than 1.8, after the forging cogging, crystal grains are refined and reduced to 40.5 mu m from 56.9 mu m, brittle carbides and internal segregation structures in the steel are broken, and the subsequent plastic deformation capacity of the material is improved due to the crystal grain refinement and the breaking of the carbides.

Preparation of extrusion: heating the blank 31 obtained after cogging forging to the extrusion forming treatment temperature (960 ℃) and preserving heat, and preheating the whole precision extrusion forming die of the steel anchoring flange to 450 ℃; the first profiling mold is assembled on the press (specifically, the first profiling punch structure is attached to the second die plate 21 and then assembled on the upper structure of the press) and a certain lubricant is applied along the working surfaces of the first punch press 222, the female die 12 and the spacer 121.

A first-time profiling step: the first press punch structure and the female die 12 are combined into a first press die, and the blank 31 obtained after the cogging forging is subjected to a first press forming process to obtain a blank 32 after the first press forming.

The method specifically comprises the following steps: the blank 31 obtained after the cogging forging is placed in the cavity of the die 12, and the first punch press 222 is placed in the blank 31 obtained after the cogging forging (see specifically fig. 5 (a)) and the press machine is lowered by 415mm.

The outer diameter of the blank 31 obtained after cogging forging is smaller than the inner diameter of the large end of the truncated cone-shaped cavity of the female die 12; one end of the blank 31 obtained after the cogging forging is placed on the backing plate 121 in the truncated cone-shaped cavity of the female die, and the other end of the blank 31 obtained after the cogging forging is placed in the cylindrical cavity of the female die 12.

Wherein, referring to the (b) diagram in fig. 5, the blank 32 after the first press forming has a flange and a neck portion in the shape of a truncated cone on one side of the flange; wherein the radial dimension of the flange of the blank 32 after the first press forming is smaller than the radial dimension of the flange of the required steel anchor flange forming member, the longitudinal dimension of the flange of the blank 32 after the first press forming is larger than the longitudinal dimension of the flange of the required steel anchor flange forming member, and the neck dimension of the blank after the first press forming is adapted to the part above the backing plate in the truncated cone-shaped cavity of the female die.

The method specifically comprises the following steps: the first punch press 222 is removed after the profiling punch 221 descends 415mm and then ascends. The working surface of the second punch press 223 is coated with a certain lubricant, and the second punch press 223 is placed on the blank 32 after the first press forming (see fig. 5 (b)) and the press is lowered by 39mm to the upset position (see fig. 5 (c)) to obtain the anchor flange blank 33.

The anchoring flange blank 33 comprises a flange, a first neck in the shape of a truncated cone and a second neck in the shape of a truncated cone; wherein the first neck is positioned at one side of the flange, and the second neck is positioned at the other side of the flange; wherein the size of the first neck is matched with the part above the backing plate 121 in the round table-shaped cavity of the female die 12; the dimensions of the second neck portion are adapted to the dimensions of the frustoconical cavity on the second punch press 223.

What should be stated here is: in the first press forming process, the blank is not fully pressed, and a set distance exists between the outer periphery of the flange on the blank 32 after the first press forming and the inner wall of the female die 12, so that in the second press forming process, the blank can be continuously filled along the radial direction while filling the round table-shaped cavity on the second male die pressing block 223, thereby being beneficial to reducing the forming load force in the second press forming process.

In addition, the cone angles of the truncated cone-shaped cavity on the second punch press block 223 and the truncated cone-shaped cavity on the female die 12 are the same, so that in the punching process, after the anchoring flange blank is turned 180 degrees, the second neck of the anchoring flange blank can be attached to the side wall of the truncated cone-shaped cavity of the female die 12.

A first punching step: the first punching male die structure and the female die 12 are combined into a first punching die, and the anchor flange blank 33 is punched to obtain an anchor flange blank 34 with punching holes. This step is specifically referred to in fig. 5 as (d) and (e).

The method specifically comprises the following steps: removing the second profiling male die structure, connecting the first punching male die structure to the second template 21, assembling the first punching male die structure on the upper structure of the press, smearing a certain lubricant along the working surfaces of the punching punch 231, the female die 12, the cushion block 121 and the limiting block 232, turning over the anchor flange blank 33 arranged on the female die 12 for 180 degrees after the second profiling, and then arranging the anchor flange blank in the cavity of the female die 12. The stopper 232 is placed at the mouth (inlet end) of the female die 12, a cylindrical pressing block is placed between the male die insert 233 and the stopper 232, the press descends, the stopper 232 is pressed into the cylindrical cavity of the female die 12, a limiting cavity matched with a required steel anchoring flange forming piece is limited with the female die 12, the anchoring flange blank 33 is internally and externally limited (at this time, a second neck part of the anchoring flange blank 33 is suspended in the truncated cone-shaped cavity of the female die 12 (a gap exists between the second neck part and the backing plate 121), a first neck part of the anchoring flange blank 33 is positioned in the truncated cone-shaped limiting cavity of the stopper and a gap exists between the first neck part and the inner wall of the truncated cone-shaped limiting cavity, so that metal can flow upwards or downwards along the axial direction in the punching punch in the process, forming load force in the punching process is reduced, and the flange of the anchoring flange blank 33 is limited between the limiting step of the stopper and the step structure of the female die. The punching punch 5 descends to punch a blank (the through hole in the stopper 232 guides the punching punch and restricts the shaking thereof). When the punch insert 233 descends to contact the stopper 232, the punch insert 233 and the stopper 232 are driven to descend together with the descending of the punching punch 5, and a force is applied to the mouth and the upper end of the anchor flange blank 34 having the punched hole, so that the metal flows toward the mouth, and the mouth shaping is completed.

A second punching step: the second piercing punch structure and the female die 12 are combined into a second piercing die, the anchor flange blank 34 with the piercing holes is further pierced, and the piercing holes are pierced, so that the steel anchor flange formed part 35 is obtained. This step is specifically referred to in fig. 5 (f).

The method specifically comprises the following steps: removing the first punching male die structure, connecting the second male die structure to the second die plate 21, and assembling the second male die structure to the press; the anchor flange blank 34 with the punched holes is removed and the pierce ring 122 is placed into the frustoconical cavity of the female die 12 and onto the backing plate 121.

Specifically, a certain lubricant is smeared along the working surfaces of the profiling punch 221, the female die 12 and the punching ring 122, then the anchoring flange blank 34 with punching holes is put into the cavity of the female die 12, the remaining bottom thick blank is punched by a press machine downwards, and the punching holes are punched through, so that the preparation of the steel anchoring flange forming piece 35 is completed; the ram 111 is moved upward and the anchor flange-forming member 35 is removed (see fig. 5 (f) and (g) for the above steps).

The steel anchor flange-forming member 35 prepared in this experimental example 1 was subjected to heat treatment, the heat treatment process being shown in fig. 14, to obtain a steel anchor flange.

Wherein the microstructure of the steel anchor flange is shown in fig. 13; wherein, after heat treatment, the needle-shaped ferrite is recrystallized, the crystal grains are further refined, and the mechanical mixed structure (tempered sorbite) of the equiaxed ferrite and cementite is obtained, the structure is uniform, and the average crystal grain size is 7.8 mu m. It can be observed by SEM that at the grain boundaries of the grains, there are compounds formed by the microalloy elements, so that the grain boundaries are not liable to migrate and the grains are not liable to grow. EDS analysis indicated the presence in the compound of the microalloying element Nb with carbon nitrogen in the steel. The pinning of the dislocation by the Nb carbon nitrogen compounds and the prevention of subgrain boundary migration hinder the grain growth rate, while the Nb prevents grain reversion strongly, producing a significant grain refinement.

Wherein the properties of the steel anchor flange are shown in table 1.

TABLE 1

In addition, fig. 15 is a graph comparing the effect of the steel anchor flange formed part obtained by adopting the conventional free punching mode and the punching mode adopting the precise extrusion forming die in the embodiment of the invention. Wherein, fig. 15 (a) is an effect diagram of a steel anchor flange forming member obtained by adopting a conventional free punching mode; fig. 15 (b) is a diagram showing the effect of the anchor flange molded article obtained by punching using a precision press-molding die according to the embodiment of the present invention.

Here, the traditional free punching mode is large in deformation resistance, under the condition of lack of constraint conditions, the punch is easy to deviate, so that the wall thickness difference is large (wherein, the wall thickness difference is 15-30 mm) and the collapse angle is generated (the collapse angle can be obviously seen from the graph (a) of fig. 15), while the wall thickness difference of the anchoring flange forming piece obtained by adopting the punching mode of the precise extrusion forming die in the embodiment of the invention is 3-5mm, the collapse angle is avoided, the material utilization rate is improved from 47.4% to 65%, and the material utilization rate is improved by more than 17%.

In summary, the precision warm extrusion forming method of the steel anchoring flange improves the dimensional precision of the steel anchoring flange forming piece, effectively regulates and controls the structure form of materials, refines grains and greatly improves the performance of the steel anchoring flange. Further, due to the adoption of the precise warm extrusion forming die of the anchoring flange, the wall thickness difference of the steel anchoring flange forming piece is reduced, the corner collapse of the forming piece opening is avoided, the material utilization rate is improved from 47.4% to 65%, and labor-saving forming is realized. Therefore, the invention improves the production efficiency and the yield of the steel anchoring flange, reduces the energy consumption and the pollution emission, effectively reduces the production procedures of the steel anchoring flange forming part, reduces the comprehensive cost, reduces the pollution emission and ensures the consistency of the product performance.

The above description is only of the preferred embodiments of the present invention, and is not intended to limit the present invention in any way, but any simple modification, equivalent variation and modification made to the above embodiments according to the technical substance of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. The precise warm extrusion forming method of the steel anchoring flange is characterized by comprising the following steps of: extruding and forming the blank obtained after the blank forging to obtain a steel anchoring flange formed part;

wherein the temperature of the extrusion forming treatment is 950-980 ℃;

wherein the average grain size of the blank obtained after the cogging forging is 30-40.5 mu m.

2. The method for precision warm extrusion forming of a steel anchor flange according to claim 1, wherein the billet obtained after the cogging forging is subjected to extrusion forming treatment by using a precision extrusion forming die of the anchor flange; wherein the step of extrusion processing includes:

3. The precision warm extrusion method of a steel anchor flange according to claim 2, characterized in that in the step of the extrusion process, the extrusion speed is 1-3mm/s.

4. The precision warm extrusion process of a steel anchor flange according to claim 2, further comprising, prior to the first profiling step:

heating the blank obtained after cogging forging to a first set temperature and preserving heat, wherein the first set temperature is the extrusion forming treatment temperature;

Preheating a precision extrusion forming die of the anchoring flange to a second set temperature and preserving heat; wherein the second set temperature is 400-450 ℃.

5. The precision warm extrusion process of a steel anchor flange as recited in any one of claims 2-4 wherein the cavity of the female die comprises:

the device comprises a cylindrical cavity, a first connecting rod and a second connecting rod, wherein the cylindrical cavity is provided with a first end and a second end which are oppositely arranged; the first end of the cylindrical cavity is opened and is used as the inlet end of the female die;

the large end of the round table-shaped cavity is directly communicated with the second end of the cylindrical cavity, and the inner diameter of the large end of the round table-shaped cavity is smaller than that of the cylindrical cavity, so that a step structure is formed at the communication position of the cylindrical cavity and the round table-shaped cavity;

the cushion block is matched with the small end of the round table-shaped cavity and is arranged at the small end of the round table-shaped cavity.

6. The precision warm extrusion process of a steel anchor flange as recited in claim 5 wherein in the first press forming step:

the blank after the first primary compression comprises a flange and a truncated cone-shaped first neck part positioned at one side of the flange; wherein the radial dimension of the flange on the blank after the first press forming is smaller than the radial dimension of the flange of the required steel anchor flange forming member; the longitudinal dimension of the flange of the blank after the first profiling is greater than the longitudinal dimension of the flange of the desired steel anchor flange forming member.

7. The method of precision warm extrusion forming a steel anchor flange according to claim 6, wherein the first neck on the first press formed blank is sized to fit over the pad in the frustoconical cavity of the die.

8. The precision warm extrusion process of a steel anchor flange as recited in claim 7 wherein the first press forming step comprises:

9. The precision warm extrusion process of a steel anchor flange as recited in claim 6 wherein in the second swage step:

the anchoring flange blank comprises a flange, a first neck in a truncated cone shape and a second neck in a truncated cone shape; wherein the first neck is located on one side of the flange and the second neck is located on the other side of the flange; the radial dimension of the flange of the anchoring flange blank is larger than that of the flange on the blank after the first-time compression; the longitudinal dimension of the flange of the anchoring flange blank is smaller than the longitudinal dimension of the flange on the blank after the first-time compression; wherein the dimensions of the second neck portion on the anchoring flange blank are adapted to the dimensions at the large end of the first neck portion.

10. The precision warm extrusion process of a steel anchor flange as recited in claim 9 wherein the second press forming step comprises:

The compression end of the second male die pressing block is provided with a round table-shaped cavity, and a large end opening of the round table-shaped cavity is positioned at the end part of the compression end; the other parts of the end parts of the profiling ends of the second punch press blocks form profiling steps relative to the large end opening of the round table-shaped cavity; when the second male die pressing block is arranged on the blank after the first pressing, a pressing step on the second male die pressing block is opposite to the step structure of the female die, and a round table-shaped cavity on the second male die pressing block is opposite to the round table-shaped cavity of the female die; the size of the truncated cone-shaped inner cavity on the second male die pressing block is matched with the size of the cavity at the large end of the truncated cone-shaped cavity of the female die.

11. The precision warm extrusion forming method of a steel anchor flange according to claim 10, wherein the first neck portion of the anchor flange blank is sized to fit over a pad in a frustoconical cavity of the female die; the size of the second neck part of the anchoring flange blank is matched with the size of the truncated cone-shaped cavity on the second punch pressing block; the periphery of the flange of the anchoring flange blank is contacted with the inner wall of the cylindrical cavity of the female die.

12. The precision warm extrusion process of a steel anchor flange as recited in claim 9 wherein in the first punching step:

the anchoring flange blank obtained after the second profiling is turned over by 180 degrees and then placed in the cavity of the female die, so that the outer limit of the anchoring flange blank is realized; the limiting block in the first punching male die structure, which is sleeved on the punching punch, is pressed into the cylindrical cavity of the female die from the inlet end of the female die, the limiting block is limited with the female die to form a limiting cavity matched with the appearance of the required steel anchoring flange forming part, and the limiting block can guide the punching punch and limit the shaking of the punching punch in the punching process, so that the internal limiting of the anchoring flange blank is realized.

13. The method for precision warm extrusion forming of a steel anchor flange according to claim 12, wherein after the anchor flange blank after the second profiling is placed in the cavity of the female die, the second neck of the anchor flange blank is placed in the truncated cone-shaped cavity of the female die, and a gap exists between the second neck and the backing plate in the female die; after the limiting block is pressed into the cavity of the female die, the anchoring flange blank is limited: the first neck of the anchoring flange blank is positioned in the round table-shaped limiting cavity of the limiting block, and a gap is formed between the first neck of the anchoring flange blank and the inner wall of the round table-shaped limiting cavity of the limiting block.

14. The precise warm extrusion forming method of the steel anchor flange according to claim 12, wherein in the punching process, after the male die insert on the punching punch contacts with the limiting block, the male die insert drives the limiting block to move downwards along with the downward movement of the punching punch, and an acting force is applied to the punched mouth of the anchor flange blank with the punched hole to finish mouth shaping; wherein the punch insert is located on an end of the punch head opposite the punch head end.

15. The method of precision warm extrusion of a steel anchor flange according to claim 12, wherein after the first punch is completed, the punch is moved upward and the stopper is brought out of the die by a belt on the punch end of the punch.

16. The precision warm extrusion process of a steel anchor flange as recited in any one of claims 2-4 wherein the second punching step comprises:

after the anchor flange blank with the punched hole is taken out of the female die, the punching ring is arranged in a cavity of the female die; placing an anchoring flange blank with punching holes in a cavity of the female die and positioning the anchoring flange blank on the punching ring; and (3) carrying out secondary punching on the anchoring flange blank with the punched hole by adopting a profiling punch with a second punching punch structure so as to punch the punched hole through, thereby obtaining the steel anchoring flange forming piece.

17. The method for precision warm extrusion forming of a steel anchor flange according to any one of claims 1 to 4, wherein the blank obtained after the cogging forging is made of CF-62 micro-alloyed steel; and/or

Before the step of extrusion forming treatment of the blank obtained after the cogging forging, cogging forging is carried out on the steel anchor flange blank to prepare the blank obtained after the cogging forging; wherein the average grain size of the steel anchoring flange blank is 56.9-70 mu m; the true strain of the cogging forging is greater than 1.8.

18. The steel anchoring flange is characterized in that the steel anchoring flange is obtained by heat treatment of a steel anchoring flange forming piece; wherein the steel anchor flange formed part is a steel anchor flange formed part obtained by the precision warm extrusion forming method of the steel anchor flange according to any one of claims 1 to 17.

19. The steel anchor flange according to claim 18, wherein the steel anchor flange has an average grain size of 7-9 μm.

20. The steel anchor flange of claim 18, wherein the tensile strength of the steel anchor flange is greater than or equal to 630MPa; the yield strength of the steel anchoring flange is more than or equal to 520MPa; the yield ratio of the steel anchoring flange is less than or equal to 0.84; the elongation rate of the steel anchoring flange is more than or equal to 25%.

21. The steel anchor flange of claim 18, wherein the steel anchor flange is CF-62 micro-alloyed steel.

22. The steel anchor flange of claim 18, wherein the heat treatment process is: and performing primary heat treatment on the steel anchoring flange forming piece at 870-940 ℃, performing secondary heat treatment on the steel anchoring flange forming piece after the primary heat treatment at 600-660 ℃ after water cooling, and obtaining the steel anchoring flange after air cooling.