CN113814287A

CN113814287A - Precise warm extrusion forming method of steel anchoring flange and steel anchoring flange

Info

Publication number: CN113814287A
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: 2021-12-21
Anticipated expiration: 2041-10-11
Also published as: CN113814287B

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: carrying out extrusion forming treatment on the blank obtained after the blank opening and forging to obtain a steel anchoring flange forming part; wherein the temperature of the extrusion molding treatment is 950-. Wherein, a precise extrusion forming die of the anchoring flange is adopted to carry out extrusion forming treatment on the blank obtained after cogging and forging. The step of extrusion forming treatment comprises a first pressing step, a second pressing 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 a 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 of 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 axial thrust from damaging each station valve chamber in large-caliber, high-pressure and long-distance oil and gas pipeline engineering, is mostly arranged at the soil-in end and the soil-out end of a pipeline, plays the roles of fixing the pipeline, restraining axial displacement of the pipeline, protecting ground pipelines and equipment in a station and the like, and plays a decisive role in ensuring the safety and the reliability of natural gas transportation. The long oil and gas transmission pipeline has the characteristics of large pipe diameter and high pressure transmission, and requires the anchoring flange to have high internal high pressure bearing capacity; in order to protect the pipeline and keep the pipeline in good integrity, the pipeline is not easy to break or deform under pressure impact under the field low-temperature condition, and the anchoring flange and the pipeline are required to have good welding performance and very high low-temperature toughness.

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

However, the production of the anchoring flange formed part by adopting the high-temperature extrusion molding process has at least the following technical problems: (1) high temperature extrusion can cause coarse grain size in the formed part, resulting in poor performance of the resulting anchoring flange; (2) the high-temperature extrusion forming process has high energy consumption; (3) after high-temperature extrusion molding, the extruded part can retract, and the shrinkage rate is higher, so that the size precision of the anchoring flange molded part is low.

Disclosure of Invention

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

In order to achieve the purpose, the invention mainly provides the following technical scheme:

in one aspect, an embodiment of the present invention provides a precision warm extrusion forming method for a steel anchoring flange, which includes the following steps: carrying out extrusion forming treatment on the blank obtained after the blank opening and forging to obtain a steel anchoring flange forming 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 μm.

Preferably, a precise extrusion forming die of an anchoring flange is adopted to carry out extrusion forming treatment on the blank obtained after cogging forging; wherein the step of extrusion processing comprises:

a first profiling step: matching the first profiling male die structure and the female die into a first profiling die, and performing first profiling treatment on the blank obtained after blank opening forging to obtain a blank subjected to first profiling;

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

a first punching step: matching a first punching male die structure and a female die into a first punching die, and punching the anchoring flange blank to obtain an anchoring flange blank with punched 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 anchoring flange blank with the punched holes, and punching the punched holes to obtain a steel anchoring flange forming part.

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

Preferably, before the first pressing step, the method further comprises: heating a blank obtained after cogging forging to a first set temperature and preserving heat, wherein the first set temperature is the temperature of the extrusion forming treatment; 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 profiling comprises a flange and a first circular truncated cone-shaped neck part positioned on one side of the flange; wherein the radial dimension of the flange on the blank after the first profiling is smaller than the radial dimension of the flange of the required steel anchoring flange forming part; the longitudinal dimension of the flange of the blank after the first compression is larger than that of the flange of the required steel anchoring flange forming part;

preferably, the size of a first neck part on the blank after the first profiling is matched with the part above the base plate in the circular truncated cone-shaped cavity of the female die;

preferably, the first pressing step includes:

discharging: one end of the blank obtained after cogging forging is arranged on a base plate in a circular truncated cone-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 circular truncated cone-shaped cavity of the female die;

first pressing: 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 profiling male die structure to move downwards, and carrying out primary profiling treatment on the blank obtained after cogging forging to obtain the blank after primary profiling.

In the second pressing step:

the anchoring flange blank comprises a flange, a first neck part in a circular truncated cone shape and a second neck part in a circular truncated cone shape; wherein the first neck portion is located on one side of the flange and the second neck portion is located on the other side of the flange; wherein the radial dimension of the flange of the anchoring flange blank is greater than the radial dimension of the flange on the blank after the first profiling; the longitudinal dimension of the flange of the anchoring flange blank is smaller than that of the flange on the blank after the first profiling; preferably, the second neck portion on the anchoring flange blank is sized to fit the size at the large end of the first neck portion.

Preferably, the second pressing step includes:

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

the pressing end of the second male die pressing block is provided with a circular truncated cone-shaped cavity, and the large end opening of the circular truncated cone-shaped cavity is positioned at the end part of the pressing end; the other part of the end part of the pressing end of the second punch press block is opened relative to the large end of the circular truncated cone-shaped cavity to form a pressing step; when the second punch press block is arranged on the blank after the first pressing, a pressing step on the second punch press block is arranged opposite to the step structure of the female die, and a circular truncated cone-shaped cavity on the second punch press block is opposite to a circular truncated cone-shaped cavity of the female die; preferably, the size of the circular 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 circular 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 base plate in the circular truncated cone-shaped cavity of the female die; the size of the second neck of the anchoring flange blank is matched with the size of the circular truncated cone-shaped cavity on the second punch press block; the periphery of the flange of the anchoring flange blank is in contact with the inner wall of the cylindrical cavity of the female die.

Preferably, in the first punching step:

turning the anchoring flange blank obtained after the secondary compression molding for 180 degrees, and then placing the anchoring flange blank into a cavity of a female die to realize the external limit of the anchoring flange blank; pressing a limiting block sleeved on a punching punch in a first punching male die structure into a cylindrical cavity of a female die from an inlet end of the female die, limiting the limiting cavity by the female die, wherein the limiting cavity is matched with the appearance of a required steel anchoring flange forming piece, and the limiting block can guide the punching punch and limit the punching punch to shake in the punching process so as to realize internal limiting of an anchoring flange blank;

preferably, after the anchoring flange blank subjected to secondary profiling is placed in a cavity of a female die, a second neck of the anchoring flange blank is placed in a truncated cone-shaped cavity of the female die, and a gap is formed between the second neck of the anchoring flange blank and a base plate in the female die; in the die cavity of the die is impressed to the stopper, carry on spacingly the back to the anchor flange blank: the first neck part of the anchoring flange blank is positioned in the circular truncated cone-shaped limiting cavity of the limiting block, and a gap is formed between the first neck part of the anchoring flange blank and the inner wall of the circular truncated cone-shaped limiting cavity of the limiting block;

preferably, in the punching process, after the punch insert on the punching punch contacts the limiting block, the punch insert drives the limiting block to move downwards along with the downward movement of the punching punch, and an acting force is applied to a punched opening part of the anchoring flange blank with the punched hole to finish the shaping of the opening part; the male die insert is positioned on one end, opposite to the punch end, of the punching punch;

preferably, after the first punching is finished, the punching punch moves 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: taking the anchoring flange blank with the punched hole out of the female die, and placing a punching ring in a cavity of the female die; then placing the anchoring flange blank with the punched hole in the cavity of the female die and on the punching ring; and punching the anchoring flange blank with the punched holes for the second time by adopting a compression punch of a second punching male die structure so as to punch the punched holes to obtain a steel anchoring flange forming part.

Preferably, the material of the billet obtained after the cogging forging is CF-62 microalloyed steel.

Preferably, before the step of performing extrusion forming processing on the blank obtained after cogging forging, cogging forging is performed on a steel anchoring flange blank to prepare the blank obtained after cogging forging; wherein the average grain size of the steel anchoring flange blank is 56.9-70 μm; the true strain of the cogging forging is greater than 1.8.

On the other hand, the embodiment of the invention provides a steel anchoring flange, wherein the steel anchoring flange formed part is obtained by any one of the steel anchoring flange precision warm extrusion forming methods;

preferably, the average grain size of the steel anchoring flange is 7-9 μm;

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

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

preferably, the heat treatment process comprises the steps of carrying out primary heat treatment on the steel anchoring flange forming piece at the temperature of 870 ℃ and 940 ℃, carrying out secondary heat treatment on the steel anchoring flange forming piece subjected to the primary heat treatment at the temperature of 600 ℃ and 660 ℃ after water cooling, and carrying out air cooling to obtain the steel anchoring flange.

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

the precise warm extrusion forming method for the steel anchoring flange provided by the embodiment of the invention firstly proposes that a warm extrusion forming method is adopted to extrude and form a steel anchoring flange forming part, namely the temperature for carrying out extrusion forming treatment on a blank obtained after cogging forging is reduced (specifically, the temperature is reduced from the high temperature of 1150-: (1) the production energy consumption of the steel anchoring flange forming part can be reduced, so that the energy is saved; (2) the warm extrusion forming can ensure that crystal grains in the material are small and precipitated phases are dispersed, so that the performance of the steel anchoring flange is greatly improved; (3) the steel anchoring flange piece after warm extrusion forming is high in dimensional accuracy, and precise extrusion forming is achieved.

Furthermore, 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-opening forging, can reduce the wall thickness difference of a steel anchoring flange forming part (further improve the precision of extrusion forming), realizes labor-saving forming and solves the problem that the mouth part of the forming part has a corner collapse in the traditional free punching of blank die forging.

In conclusion, the precision warm extrusion forming method of the steel anchoring flange improves the dimensional precision of an extrusion formed part, effectively regulates and controls the material tissue form, refines crystal grains and can greatly improve the performance of the steel anchoring flange; furthermore, the wall thickness difference of the steel anchoring flange forming part can be reduced, the mouth part of the forming part is prevented from collapsing, the utilization rate of materials is improved to 65% from 47.4%, the production efficiency and the yield are improved, the energy consumption and pollution emission are reduced, the production processes 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.

The foregoing description is only an overview of the technical solutions of the present invention, and in order to make the technical solutions of the present invention more clearly understood and to implement them in accordance with the contents of the description, the following detailed description is given with reference to the preferred embodiments of the present invention and the accompanying drawings.

Drawings

FIG. 1 is a schematic view of an assembly of a first profiling mold provided by an embodiment of the present invention;

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

FIG. 3 is an assembled schematic view of a first hole punch provided in accordance with an embodiment of the present invention;

FIG. 4 is an assembled schematic view of a second hole punch provided in accordance with an embodiment of the present invention;

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

FIG. 6 is a schematic view of the assembly of a first punch configuration with a second die plate provided by 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 male die structure provided by the embodiment of the invention;

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

figure 9 is a partial schematic view of a punch provided in accordance with an embodiment of the invention;

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

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

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

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

FIG. 14 is a heat treatment process diagram;

FIG. 15 is a graph comparing the effect of a steel anchoring flange formed part obtained by a conventional free-form punching method and a punching method using a precision extrusion die according to an embodiment of the present invention.

Detailed Description

To further explain the technical means and effects of the present invention adopted to achieve the predetermined object, the following detailed description of the embodiments, structures, features and effects according to the present invention will be made with reference to the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "an embodiment" refers to not necessarily the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

Example 1

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

The embodiment firstly proposes that a steel anchoring flange forming part is formed by extrusion by adopting a warm extrusion forming method, namely, the temperature for carrying out extrusion forming treatment on a blank 31 obtained after blank opening forging is reduced; (specifically, the temperature is reduced from the high temperature of 1150-1200 ℃ in the prior art to the medium temperature of 950-980 ℃), and the reduction of the extrusion forming temperature can achieve at least the following three effects: the production energy consumption of the steel anchoring flange forming part can be reduced, so that the energy is saved; the warm extrusion forming can ensure that crystal grains in the material are small and precipitated phases are dispersed, so that the performance of the steel anchoring flange is greatly improved; the steel anchoring flange piece after warm extrusion forming is high in dimensional accuracy, and precise extrusion forming is achieved.

Here, it should be noted that: the precondition for achieving the warm extrusion molding is that the billet is refined by cogging forging (i.e., repeated upsetting and elongation treatment) to improve the plasticity of the billet itself (good metal fluidity), and specifically, the properties of the billet obtained after cogging forging satisfy 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 of extrusion molding at a reduced temperature.

The precise warm extrusion forming method for the steel anchoring flange provided in the embodiment 1 can be applied to a steel anchoring flange die in the prior art.

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

Example 2

In this embodiment, in addition to embodiment 1, in order to further improve the dimensional accuracy (reduce the wall thickness difference) of the steel anchor flange formed piece and improve the utilization rate of the material, it is proposed to perform the extrusion processing on the billet obtained after the cogging forging by using the precision extrusion die of the anchor flange. Here, the present embodiment mainly describes the structural features of the precision extrusion molding die of the anchor flange in detail as follows:

as shown in fig. 1 to 10, the anchoring precision extrusion molding 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 comprises: a first piercing punch arrangement (for cooperating with the female die 12 to form a first piercing die for piercing the anchoring flange blank 33); preferably, the second die further comprises a second punch structure (for further punching the anchor flange blank 34 with punched holes obtained after punching the first punch die, so as to punch through the punched holes). Preferably, the second die further comprises a first profiling male die structure (for cooperating with the female die to form a first profiling die), and a second profiling male die structure (for cooperating with the female die to form a second profiling die), so as to profile the blank 31 obtained after cogging forging into the anchoring flange blank 33 to be punched.

In addition, the first die assembly further comprises a first die plate 11 for connecting the press (in particular, the first die plate 11 is used for connecting the lower structure of the press); wherein the female die 12 is fixed on the first die plate 11. The second die assembly further comprises a second die plate 21 for attaching to the press (in particular, a second die plate for attaching to the upper structure of the press). The first punching male die structure, the second punching male die structure, the first pressing male die structure and the second pressing male die structure are used for being fixed on the second template 21 when being matched with the female die 12.

On one hand, the structure of the first punching male die, the structure of the female die 12 and the cooperation thereof are explained as follows: a first piercing punch structure (here, the first piercing punch structure refers to an M-shaped combined punch structure fixed to the second die plate 21 shown in fig. 6). Wherein the first punching male die structure is used for cooperating with the female die 12 to form a first punching die for punching the anchoring flange blank 33. 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 to shake in the punching process. During punching, the limiting block 232 is used for being pressed into a cavity of the female die 12, limiting the female die 12 to form a limiting cavity (preferably, the limiting cavity is a closed cavity) matched with the external dimension of a required steel anchoring flange forming piece, and limiting the anchoring flange blank 33 inside and outside simultaneously (here, explanation about the inside and outside simultaneous limiting is as follows, for the blank, the female die in the limiting cavity can limit the blank to form an outside limiting, and the limiting block can limit the punch so that the punch cannot deviate in the punching process to form an inside limiting). Through the arrangement, in the whole punching process, the movement of the anchoring flange blank 33 can be limited by the matching of the limiting block 232 and the female die 12 (namely, the anchoring flange blank 33 is fixed), the limiting block 232 limits the punching punch 231 to swing, so that the punching punch 231 can directly and straightly punch a hole on the anchoring flange blank 33, the wall thickness difference of the steel anchoring flange forming piece 35 formed by extrusion is reduced, and the utilization rate of materials is further improved.

Preferably, as shown in fig. 1 to 5, the female die 12 is designed in the following structure: 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 cushion block 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 arranged as the inlet end of the concave die 12. The big end of the circular truncated cone-shaped cavity is directly communicated with the second end of the cylindrical cavity, and the inner diameter of the big end of the circular truncated cone-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 circular truncated cone-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 circular truncated cone-shaped cavity and is arranged at the small end of the circular truncated cone-shaped cavity. Preferably, the small end of the circular truncated cone-shaped cavity is open, and the small end of the circular truncated cone-shaped cavity is open and located at the end 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, and the first template 11 is provided with an ejector rod mounting hole which corresponds to the small end opening of the circular truncated cone-shaped cavity. The first mold assembly further comprises ejector pins 111; the top end of the ejector rod 111 is arranged in the ejector rod mounting hole of the first template; further preferably, the axis of the top rod 111 and the axis of the top rod mounting hole are located on the same straight line; the arrangement is that the ejector rod goes upwards to realize demoulding and unloading.

Preferably, as shown in fig. 1 to 7 and 10, on the basis of the structure of the female die 12, the present embodiment further designs the structure of the stopper 232 in the first punching male die structure (M-shaped combined male die structure): the stopper 232 has a first end (the lower end of the stopper 232 shown in fig. 10), and the first end of the stopper 232 is provided with a truncated cone-shaped stopper cavity 2321 (i.e., a truncated cone-shaped stopper cavity); the large end of the circular truncated cone-shaped limiting cavity 2321 is open, and the opening at the large end of the circular truncated cone-shaped limiting cavity 2321 is located at the first end of the limiting block 232, so that other parts of the first end of the limiting block 232 form limiting steps relative to the circular truncated cone-shaped limiting cavity 2321. Wherein, after the stopper 232 is pressed into the cylindrical cavity from the inlet end of the female die 12: the limit step of the limit block 232 is arranged opposite to the step structure in the cavity of the female 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 butt 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 female die, and the limit step of the limit block is in butt 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 the cone angle 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 truncated cone-shaped limiting cavity 2321 is larger (slightly larger) than the inner diameter of the large-end opening of the circular truncated cone-shaped cavity of the female die 12. The 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 gap is reserved between the upper neck and the inner wall of the truncated cone-shaped limiting cavity.

Preferably, the 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 peripheral dimension of the limiting block 232 is larger than the diameter of the cylindrical cavity (the dimension is slightly larger than the diameter, so that the limiting block 232 can enter the cylindrical cavity and the limiting block 232 can limit the anchoring flange blank 33); wherein, the inlet end of the female die 12 (the mouth of the female die) is provided with a chamfer so that the stopper 232 can be pressed into the cylindrical cavity of the female die 12.

Here, it should be noted that: the cavity of the female die 12 is set into a cylindrical cavity and a circular truncated cone-shaped cavity structure which are communicated, and a step structure is formed at the communication position of the cylindrical cavity and the large end of the circular truncated cone-shaped cavity; meanwhile, a first end of the limiting block 232 is provided with a truncated cone-shaped limiting cavity, the large end of the truncated cone-shaped limiting cavity is open, and the opening is positioned at the end part of the first end of the limiting block 232, so that other parts of the end part of the first end of the limiting block 232 form limiting steps relative to the truncated cone-shaped limiting cavity; with the arrangement, after the limiting block 232 is pressed into the cylindrical cavity of the female die 12, the limiting cavity matched with the outline dimension of the required steel anchoring flange forming piece can be limited out of the cavity of the female die 12; moreover, one neck (lower neck) of the anchoring flange blank 33 is constrained by the truncated cone-shaped cavity of the female die 12, so that the outer limiting 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 constrain the punch, so that the punch cannot deviate and the inner limiting of the anchoring flange blank is realized; therefore, the female die 12 and the limiting block 232 of the above structure can limit the anchoring flange blank inside and outside simultaneously.

Preferably, as shown in fig. 1 to 10, the present embodiment further designs the structure of the stopper 232 and the piercing punch 231 in the first piercing punch structure (M-shaped combined punch structure), and the connection manner between the stopper 232 and the piercing punch 231, as follows: the stop block 232 has a second end (the upper end of the stop block shown in fig. 10), and the second end of the stop block 232 is opposite to the first end of the stop block 232; a through hole 2322 is formed at the second end of the limiting block 232, and is used for sleeving the limiting block 232 on the punching punch 231 so as to guide the punching punch 231 and limit the punching punch 231 to swing; the through hole 2322 is communicated with the round platform-shaped limiting cavity 2321, the through hole 2322 is matched with the peripheral dimension of the cylinder of the punching punch 231, and the inner diameter of the through hole 2322 is smaller than that of the small end of the round platform-shaped limiting cavity 2321.

Preferably, the head of the punching punch 231 is provided with a working tape 2311; the diameter of the working tape 2311 is larger than the diameter of the cylinder of the punching punch 231, and the diameter of the working tape 2311 is smaller than the inner diameter of the small end of the truncated cone-shaped limiting cavity 2321 (so that the working tape 2311 can penetrate through the truncated cone-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 of the small end of the circular truncated cone-shaped limiting cavity 2321 to accommodate the working tape 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. Above-mentioned setting not only can reduce forming load and drawing die power, and simultaneously after punching a hole, the drift 231 that punches a hole can take up stopper 232.

Regarding the structural features of the stop block 232, in combination with the drawings, it can be seen that the stop block 232 is an M-shaped stop block.

Here, in the present embodiment, the through hole 2322 that is communicated with the circular truncated cone-shaped limiting cavity and is adapted to the peripheral dimension of the cylinder of the punching punch 231 is formed in the limiting block 232, so that the limiting block 232 is sleeved on the punching punch 231, the guiding of the punching punch 231 is realized through the through hole 2322 in the limiting block, and the shaking of the punching punch 231 is limited. Further, in the embodiment, the working strip 2311 is arranged at the head of the punching punch 231, the accommodating cavity 2323 is arranged at the intersection of the through hole wall of the limit block 232 and the end part of the small end of the circular truncated cone-shaped limit cavity and is used for accommodating the working strip 2311 of the punching punch 231, so that the forming load and the drawing force are reduced conveniently on one hand, and the limit block 232 can be taken up after the punching is finished on the other hand.

Preferably, as shown in fig. 3 and 5, the present embodiment further designs the first punching die 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 the limiting cavity matched with the overall dimension of the required steel anchoring flange forming part: the cavity wall of the limiting 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 limiting 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 limiting cavity. Specifically, during 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 left 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 part of the second neck part and the backing plate 121 in the truncated cone-shaped cavity of the female die 12. The upper side of the flange of the anchoring flange blank 33 is tightly attached to the limiting step of the limiting 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 portion (lower neck portion) 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 portion (upper neck portion) of the anchoring flange blank 33 and the stopper 232; due to the arrangement, in the punching process, metal flows in the upper direction and the lower direction simultaneously, short-distance flow is controlled, and compared with the traditional backward extrusion, the metal flow path is reduced, and the labor-saving forming effect is achieved; the labor-saving forming can reduce the energy consumption and prolong the service life of the die.

It should be noted that: due to the flowing of metal in the punching process, when the punched hole reaches a preset position, the shape of the anchoring flange blank with the punched hole is matched with the size of the limiting cavity, namely, no gap exists between the anchoring flange blank with the punched hole and the limiting block and between the anchoring flange blank with the punched hole and the concave die.

Preferably, as shown in fig. 3, 5, 6 and 8, the first punching male die structure of the present embodiment is further designed as follows: the first piercing punch construction further comprises a punch insert 233; wherein the punch 231 has a first end (lower end) and a second end (upper end) disposed opposite to each other; wherein, the head of the punch 231 is located at the first end (lower end, punch end) of the punch, wherein, the male die insert 233 is sleeved on the second end (upper end, fixed end) of the punch; in the punching process, the punch insert 233 moves downward along with the punching punch 231, and when the punch insert 233 moves downward to contact with the stopper 232 (see fig. 5 (e)), the punch insert 233 drives the stopper 232 to move downward together with the continued downward movement of the punching punch 211, and the punch insert 233 and the stopper 232 together apply an acting force to the mouth portion (i.e., the upper mouth portion) of the punched hole of the anchoring flange blank 34 having the punched hole.

Here, in the present embodiment, the first piercing punch structure includes the punch insert 233 sleeved at the second end (the end opposite to the head of the piercing punch) of the piercing punch 231, and during the piercing process, as the piercing punch 231 descends, when the punch insert 233 descends to contact with the limit block 232, the punch insert 233 and the limit block 232 exert a force on the mouth of the piercing hole of the anchor flange blank 34 with the piercing hole, so that the shaping function is performed, the mouth of the extruded anchor flange formed part is flush, the problem of corner collapse of the mouth of the formed part in the conventional blank die forging free piercing is solved, and the material utilization rate is further improved.

Preferably, the punch insert 233 has a first through hole and a second through hole which are communicated with each other, and the inner diameter of the first through hole is larger than that of the second through hole; wherein an end portion of the second end of the piercing punch 231 is provided as a connecting portion; 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 at the second end of the punching punch; with the above arrangement, the male die insert 233 is sleeved with the second end of the piercing punch 231.

Preferably, the first piercing punch arrangement is connected to the second die plate 21 by a punch insert 233. Specifically, the first punching male die structure further includes a male die holder 234; wherein, the punch holder 234 crimps (tightly connects) the punch insert 233 to the pressure plate 235; the punch retainer 234, the press plate 235, and the second die plate 21 are fastened together by fasteners (e.g., bolts).

The above description has been made about the female die, the first punching punch structure, and the combination of both, but the anchoring flange blank 33 is punched with the first punching punch structure as described above, but is not punched with a through hole, and the punched hole of the anchoring flange blank 34 having the punched hole also has a bottom portion as shown in fig. 5 (e).

On the other hand, as shown in fig. 4 and 5, the second punching male die structure of the present embodiment is used to form a second punching die in cooperation with the female die 12, and is used to further punch the anchoring flange blank 34 having the punched hole obtained after punching by the first punching die, so as to punch the punched hole thereon (i.e., punch away the remaining bottom-thickness blank) to obtain the anchoring flange forming 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 punch die assembly further includes a punch ring 122 for seating within the cavity of the female die 12 when punching and for supporting the anchoring flange blank 34 with punched holes where it is to be punched. In particular, before punching. A punching ring 122 is placed on the spacer 121 in the frustoconical cavity of the female die 12, and the end of the lower neck of the anchoring flange blank 34 with the punched holes is placed on the punching ring 122.

On the other hand, as shown in fig. 1 to 3 and 5, the first pressing male die structure, the second pressing male die structure and the cooperation with the female die 12 in the second die assembly for cooperating with the female die to press the anchoring flange blank 33 to be punched are specifically as follows:

the first profiling male die structure is used for being matched with the female die 12 to form a first profiling die and is used for performing first profiling treatment on a blank 31 (namely, a cylindrical blank) obtained after blank-opening forging, wherein the first profiling male die structure comprises a profiling punch 221 and a first male die pressing block 222; wherein, the profiling punch 221 is used for connecting the second template 21; the first punch press 222 is of a plate structure for applying a pressing force to the billet 31 obtained after the cogging forging set 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 carrying out 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 press punch structure comprises a press punch 221 (the press punch 221 is used for connecting the second die plate 21) and a second punch press 223.

Wherein the second punch press block 223 has a first end (a press end) and a second end which are oppositely arranged; wherein, a first end of the second punch press block 223 is provided with a truncated cone-shaped cavity; the large end of the circular truncated cone-shaped cavity is open, and the large end opening of the circular truncated cone-shaped inner cavity on the second punch press block 223 is located at the end of the first end of the second punch press block 223, so that other parts on the end of the first end of the second punch press block 223 form a pressing step relative to the circular truncated cone-shaped cavity. When the second pressing is performed, the pressing punch 221 abuts against the end of the second punch press 223, so that the second punch press 223 performs the second pressing on the blank 32 after the first pressing; during the second pressing treatment, the second punch press block 223 is pressed into the female die 12, the pressing step is arranged opposite to the step structure of the female die 12, and the circular truncated cone-shaped cavity on the second punch press block 223 is opposite to the circular truncated cone-shaped cavity of the female die 23.

Preferably, the size of the truncated cone-shaped cavity on the second punch press block 223 is adapted to the size of the cavity at the large end of the truncated cone-shaped cavity of the female die 12 (i.e., the taper angle of the two is the same, but the depth of the truncated cone-shaped cavity is smaller than the distance between the large end opening of the truncated cone-shaped cavity and the backing plate 121).

Example 3

Preferably, this embodiment is based on embodiment 2, and as shown in fig. 5, further describes the step of performing warm extrusion forming processing on the blank obtained after cogging and forging by using a precision extrusion forming die of the anchor flange, and mainly includes:

preparation of molding: heating the blank 31 obtained after cogging forging to a first set temperature and preserving heat, wherein the first set temperature is the temperature of extrusion forming treatment (namely 950-; preheating a precise extrusion forming die of the anchoring flange to a second set temperature and preserving heat; wherein the second set temperature is 400-450 ℃ to reduce the deformation unevenness caused by heat exchange.

In addition, a first press type male die structure and a female die are assembled on the press, matched into a first press type die (specifically, the first press type male die structure is connected to the second template 21 and then assembled on the upper structure of the press), and a certain lubricant is coated along the working surfaces of the first male press block 222, the female die 12 and the cushion block 121.

A first profiling step: and (3) matching the first pressing male die structure and the female die 12 into a first pressing die, and performing first pressing treatment on the blank 31 obtained after blank opening and forging to obtain a blank 32 after the first pressing. Preferably, the step comprises:

discharging: one end of the blank 31 obtained after cogging forging is arranged on the backing plate 121 in the circular truncated cone-shaped cavity of the female die 12, and the other end of the blank 31 obtained after cogging forging is positioned in the cylindrical cavity of the female die 12; the blank 31 obtained after cogging forging is a cylindrical blank, and 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 die 12.

First pressing: a first punch press block 222 (a certain lubricant is coated on the working surface of the first punch press block) in the first profiling punch structure is pressed into a cylindrical cavity of the female die 12 and is placed on a blank 31 obtained after cogging forging; controlling a first pressing male die structure to descend, and carrying out primary pressing treatment on a blank 31 obtained after blank opening forging to obtain a blank 32 after primary pressing;

the blank 32 after the first profiling comprises a flange and a first truncated cone-shaped neck part (only one neck part) positioned on one side of the flange; wherein, the radial dimension of the flange on the blank 32 after the first profiling is smaller than that of the flange of the required steel anchoring flange forming member 35; the longitudinal dimension of the flange of the blank 32 after the first profiling is greater than the longitudinal dimension of the flange of the desired steel anchoring flange formation 35. Wherein, the size of the first neck part on the blank 32 after the first pressing is matched with the part above the backing plate 121 in the circular truncated cone-shaped cavity of the female die 12.

And a second pressing step: and matching the second pressing male die structure and the female die 12 into a second pressing die, and performing second pressing treatment on the blank 32 subjected to the first pressing to obtain an anchoring flange blank 33.

Specifically, in the second press molding step: removing the first punch compact 222; matching the second punch press block 223 with the profiling punch 221 to form a second profiling punch structure, pressing the second punch press block 223 (a certain amount of lubricant is coated on the working surface (the end part of the profiling end) of the second punch press block 223) in the second profiling punch structure into the cylindrical cavity of the female die 12, and placing the second punch press block 223 on the blank 32 after the first profiling; and controlling the second pressing male die structure to move downwards, and performing primary pressing treatment on the blank 32 subjected to primary pressing to obtain an anchoring flange blank 33.

When the second punch press block 223 is placed on the blank 32 after the first pressing, the pressing step on the second punch press block 223 is arranged opposite to the step structure of the female die 12, and the circular truncated cone-shaped cavity on the second punch press block 223 is opposite to the circular truncated cone-shaped cavity of the female die 12. The size of the circular 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 circular truncated cone-shaped cavity of the female die.

Preferably, the anchoring flange blank 33 comprises a flange, a frustoconical first neck portion and a frustoconical second neck portion; wherein the first neck portion is positioned at one side of the flange, and the second neck portion 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 that of the flange on the blank 32 after the first profiling; the longitudinal dimension of the flange of the anchoring flange blank 33 is smaller than the longitudinal dimension of the flange on the blank 32 after the first profiling; preferably, the size of the second neck on the anchoring flange blank 33 is adapted to the size at the large end of the first neck.

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 size of the second neck of the anchoring flange blank 33 is matched with the size of the truncated cone-shaped cavity on the second punch press block 223; the periphery of the flange of the anchoring flange blank 33 is in contact with the inner wall of the cylindrical cavity of the female die 12.

A first punching step: and matching the first punching male die structure and the female die 12 into a first punching die, and punching the fixed flange blank 33 to obtain the anchoring flange blank 34 with punched holes.

In the first punching step: turning the anchoring flange blank obtained after the secondary compression molding by 180 degrees, and placing the anchoring flange blank in a cavity of a female die to realize the external 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, the limiting cavity matched with the appearance of the required steel anchoring flange forming piece 35 is limited by the female die 12, the limiting block 232 can guide the punching punch and limit the punching punch to swing in the punching process, and internal limiting of the anchoring flange blank 33 is achieved. Therefore, the punching punch 231 can vertically punch the anchoring flange blank 33, so that the wall thickness difference of the steel anchoring flange formed part 35 formed by extrusion is reduced, the dimension precision of extrusion is improved, and the utilization rate of materials is improved.

Preferably, after the anchoring flange blank 33 obtained after the second profiling is placed in the cavity of the female die 12, the second neck portion of the anchoring flange blank 33 is placed in the truncated cone-shaped cavity of the female die 12, and a gap is formed between the second neck portion and the backing plate 121 in the female die 12; in the die cavity of die 12 is impressed at stopper 232, carry out spacing back to anchor flange blank 33: the first neck of the anchoring flange blank 33 is located in the circular truncated cone-shaped limiting cavity of the limiting block 232, and a gap exists between the inner wall of the circular truncated cone-shaped limiting cavity of the limiting block 232. Therefore, in the punching process, metal flows in the upper direction and the lower direction simultaneously, short-distance flow is controlled, and compared with the traditional backward extrusion, the metal flow path is reduced, and the effect of labor-saving forming is achieved; the labor-saving forming can reduce the energy consumption and prolong the service life of the die.

Preferably, the first punching step further comprises: in the punching process, after the punch insert 233 at one end of the punching punch 231, which is opposite to the punch end, is contacted with the limiting block 232, the punch 231 moves downwards to drive the punch insert 233 and the limiting block 232 to move downwards together, acting force is applied to the mouth part of the punched hole of the anchoring flange blank with the punched hole, metal flows towards the mouth part, and mouth part shaping is completed, so that the mouth part of the anchoring flange formed part formed by extrusion forming is flush, the problem of corner collapse of the mouth part of the formed part in the traditional blank die forging free punching is solved, and the utilization rate of materials is further improved.

Preferably, after the first punching, the punching punch 231 moves upward, and the stopper 232 is taken out of the die 12 by the working tape 2311 on the punch end of the punching punch 231.

Preferably, before the inner and outer limiting of the anchoring flange blank 33, the method further comprises: and removing the second profiling male die, assembling the second module 21 and the first punching male die structure (M-shaped combined male die) on the press, and coating a certain amount of lubricant along the working surfaces of the punching punch 231, the female die 12, the cushion block 121 and the limiting block 232.

In addition, the punched anchoring flange blank 34 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 part is matched with the circular truncated cone-shaped limiting cavity of the limiting block 232, and the size of the second neck part is matched with the part above the backing plate 121 in the female die 12.

A second punching step: and matching the second punching male die structure and the female die 12 into a second punching die, further punching the anchoring flange blank 34 with the punched holes, and punching the punched holes to obtain a steel anchoring flange formed part 35.

The method comprises the following steps: after the anchoring flange blank 34 with the punched holes is taken out of the female die, the punching ring 122 is placed in the cavity of the female die 12; then the anchoring flange blank 34 with the punched hole is placed in the cavity of the female die 12 and is positioned on the punching ring 122; and punching the punched anchoring flange blank 34 for the second time by using the profiling punch 221 of the second punching male die structure so as to punch the punched hole, thereby obtaining the steel anchoring flange piece 35.

Preferably, the steps specifically include: removing the first punching male die structure, removing the anchoring flange blank 34 with punched holes, placing the punching ring 122 in the cavity of the female die 12, coating a certain amount of lubricant along the working surfaces of the profiling punch 221, the female die 12 and the punching ring 122, then placing the anchoring flange blank 34 with punched holes in the cavity of the female die 12, downward punching the residual bottom-thick blank by a press machine, completing the preparation of an anchoring flange formed piece, upward punching by a push rod, and removing the steel anchoring flange formed piece 35.

In addition, in the above-mentioned step of the extrusion process, the extrusion speed is 1 to 3mm/s, and a slower extrusion speed is adopted to lower the forming force.

To sum up: the precise warm extrusion forming method for 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 method in the prior art, the die forging temperature is reduced), so that the performance of the steel anchoring flange is improved, the size precision of an anchoring flange forming part is improved, and the production energy consumption of the anchoring flange is reduced. On the basis, the embodiment of the invention further adopts a precision 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 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 in the traditional blank die forging free punching is subjected to corner collapse is solved.

In conclusion, the precision warm extrusion forming method of the steel anchoring flange improves the precision of extrusion forming, effectively regulates and controls the material structure form, refines crystal grains and greatly improves the performance; furthermore, the wall thickness difference of the steel anchoring flange forming part is reduced, the corner collapse at the opening part is avoided, the utilization rate of materials is improved to 65% from 47.4%, the production efficiency and the yield are improved, the energy consumption and 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 anchoring flange formed by the precise warm extrusion forming method of the steel anchoring flange is subjected to heat treatment to obtain the steel anchoring flange. Wherein, the heat treatment process is shown in fig. 14; specifically, the heat treatment process comprises the following steps: and (3) carrying out primary heat treatment on the steel anchoring flange forming piece at the temperature of 870 ℃ and 940 ℃ (preferably, the time of the primary heat treatment is 3 hours), carrying out secondary heat treatment on the steel anchoring flange forming piece after the primary heat treatment at the temperature of 600 ℃ and 660 ℃ (preferably, the time of the secondary heat treatment is 4 hours) after water cooling, and obtaining the steel anchoring flange after air cooling.

Preferably, the steel anchoring flange formed part and the steel anchoring flange provided by the embodiment of the present invention are made of CF-62 modified special steel (i.e., CF-62 microalloyed steel), and the chemical compositions (%) are 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 to 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. Note, 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 80 ppm.

The following are further detailed by specific experimental examples as follows:

experimental example 1

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

cogging and forging: cogging and forging the steel anchoring flange blank to obtain a blank 31 obtained after cogging and forging.

The microstructure of the steel anchoring flange blank is shown in fig. 11. The microstructure of the billet obtained after the cogging forging is shown in fig. 12. The original structure of the steel anchoring flange blank is austenite plus pearlite, the true strain of forging cogging is larger than 1.8, after 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 steel are broken, and the subsequent plastic deformation capacity of the material is improved by grain refinement and carbide breakage.

Preparing for extrusion molding: heating the blank 31 obtained after cogging forging to the temperature of extrusion forming treatment (960 ℃), preserving heat, and integrally preheating a precision extrusion forming die of the steel anchoring flange to 450 ℃; the first profiled die is assembled on the press (in particular, the first profiled male structure is attached to the second template 21 and then assembled on the upper structure of the press) and a lubricant is applied along the working surfaces of the first male block 222, the female die 12 and the spacer 121.

A first profiling step: and (3) matching the first pressing male die structure and the female die 12 into a first pressing die, and performing first pressing treatment on the blank 31 obtained after blank opening and forging to obtain a blank 32 after the first pressing.

The method comprises the following steps: the blank 31 obtained after cogging forging is placed in the cavity of the female die 12, and the first male die press block 222 is placed in the blank 31 obtained after cogging forging (see fig. 5 (a) in particular), and the press descends 415 mm.

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

As shown in fig. 5 (b), the blank 32 after the first press forming has a flange and a truncated cone-shaped neck portion on the flange side; the radial dimension of the flange of the blank 32 after the first pressing is smaller than that of the flange of the required steel anchoring flange forming piece, the longitudinal dimension of the flange of the blank 32 after the first pressing is larger than that of the flange of the required steel anchoring flange forming piece, and the neck dimension of the blank after the first pressing is matched with the part above the cushion plate in the circular truncated cone-shaped cavity of the female die.

The method comprises the following steps: the first punch compact 222 is removed after 415mm of downward travel of the profiling punch 221. Applying a certain amount of lubricant to the working surface of the second punch press 223, placing the second punch press 223 on the blank 32 after the first pressing (see (b) in fig. 5), and moving the press down 39mm to the upsetting position (see (c) in fig. 5), thereby obtaining the anchoring flange blank 33.

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

Here, it should be noted that: in the first pressing process, the blank is not fully pressed, and a set distance exists between the periphery of the flange on the blank 32 after the first pressing and the inner wall of the female die 12, so that in the second pressing process, the blank can be continuously filled along the radial direction while filling the truncated cone-shaped cavity on the second male die pressing block 223, and the forming load force in the second pressing process can be reduced.

In addition, the cone angle of the truncated cone-shaped cavity on the second punch press block 223 is the same as that of the truncated cone-shaped cavity on the female die 12, so that 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 after the anchoring flange blank is turned over for 180 degrees in the punching process.

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

The method comprises the following steps: and removing the second pressing 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 amount of lubricant along the working surfaces of the punching punch 231, the female die 12, the cushion block 121 and the limiting block 232, turning the anchoring flange blank 33 placed on the female die 12 after the second pressing for 180 degrees, and then placing the anchoring flange blank in the cavity of the female die 12. The limiting block 232 is arranged at the mouth part (inlet end) of the female die 12, a cylindrical pressing block is arranged between the male die insert 233 and the limiting block 232, the press machine moves downwards, the limiting block 232 is pressed into the cylindrical cavity of the female die 12, and a limiting cavity matched with a required steel anchoring flange forming part is limited by the female die 12, and the anchoring flange blank 33 is limited internally and externally (at the moment, 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 limiting block, 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 downward pressing process of the punching punch, the forming load force in the punching process is reduced, and the flange of the anchoring flange blank 33 is limited between a limiting step of the limiting block and a step structure of the female die). The punch 5 goes down to punch the blank (the through hole on the stopper 232 guides the punch and restricts the swing of the punch). When the punch insert 233 moves downwards to contact the limiting block 232, the punch insert 233 and the limiting block 232 are driven to move downwards together with the downward movement of the punching punch 5, acting force is applied to the mouth part and the upper end of the anchoring flange blank 34 with the punched hole, metal flows towards the mouth part, and mouth part shaping is completed.

A second punching step: and matching the second punching male die structure and the female die 12 into a second punching die, further punching the anchoring flange blank 34 with the punched holes, and punching the punched holes to obtain a steel anchoring flange formed part 35. This step is specifically referred to in fig. 5 (f).

The method comprises the following steps: removing the first piercing punch structure, attaching the second punch structure to the second die plate 21 and assembling on a press; the anchoring flange blank 34 with the punched holes is taken out, and the punching ring 122 is placed in the truncated cone-shaped cavity of the female die 12 and is positioned on the backing plate 121.

Specifically, a certain amount of lubricant is smeared along the working surfaces of the profiling punch 221, the female die 12 and the punching ring 122, then the anchor flange blank 34 with the punched hole is placed into a cavity of the female die 12, the press machine moves downwards to punch off the residual bottom thick blank, the punched hole is punched through, and the preparation of the steel anchor flange forming part 35 is completed; ram 111 is moved up and anchoring flange formation 35 is removed (see fig. 5 (f) and (g) for the above steps).

The steel anchoring flange formed piece 35 prepared in experimental example 1 was subjected to heat treatment, and the heat treatment process is shown in fig. 14, thereby obtaining a steel anchoring flange.

Wherein, the microstructure of the steel anchoring flange is shown in figure 13; wherein, after the heat treatment, the needle-shaped sheet ferrite is recrystallized, the crystal grains are further refined, and a mechanical mixed structure (tempered sorbite) of equiaxial ferrite and cementite is obtained, the structure is uniform, and the average crystal grain size is 7.8 mu m. According to SEM, compounds formed by microalloy elements exist in the grain boundary of the crystal grains, so that the grain boundary is not easy to migrate, and the crystal grains are not easy to grow. EDS analysis shows that the compound contains a compound formed by the microalloy element Nb and carbon nitrogen in steel. The pinning of the carbon nitride of Nb to dislocation and the prevention of the migration of subgrain boundary hinder the grain growth rate, and meanwhile, the effect of Nb on preventing the grain recovery is strong, so that the remarkable grain refining effect is generated.

The properties of the steel anchoring flange are shown in table 1.

TABLE 1

Fig. 15 is a graph showing a comparison between the effect of a steel anchoring flange formed member obtained by the conventional free-form punching method and the effect of a steel anchoring flange formed member obtained by the punching method using the precision extrusion die according to the embodiment of the present invention. Wherein, the drawing (a) in fig. 15 is an effect drawing of a steel anchoring flange forming piece obtained by adopting a traditional free type punching mode; fig. 15 (b) is an effect diagram of an anchor flange molded product obtained by a punching method using a precision extrusion die according to an embodiment of the present invention.

Here, in the conventional free punching manner, due to large deformation resistance and lack of constraint conditions, the punch is easy to deviate, so that the wall thickness difference is large (wherein, the wall thickness difference is 15-30mm), and a corner collapse is generated (the corner collapse can be obviously seen from a diagram (a) of fig. 15), whereas the wall thickness difference of the anchor flange formed part obtained by adopting the punching manner of the precise extrusion forming die in the embodiment of the invention is 3-5mm, the corner collapse is not generated, the material utilization rate is improved from 47.4% to 65%, and the material utilization rate is improved by more than 17%.

In conclusion, the precision warm extrusion forming method of the steel anchoring flange provided by the invention improves the dimensional precision of a steel anchoring flange forming part, effectively regulates and controls the tissue form of materials, refines crystal grains and greatly improves the performance of the steel anchoring flange. Furthermore, due to the adoption of the precise warm extrusion forming die for the anchoring flange, the wall thickness difference of a steel anchoring flange forming part is reduced, and the corner collapse of the opening part of the forming part is avoided, so that the material utilization rate is improved to 65 percent from 47.4 percent, and the labor-saving forming is also 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 a preferred embodiment of the present invention, and is not intended to limit the present invention in any way, and any simple modification, equivalent change and modification made to the above embodiment according to the technical spirit of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A precise warm extrusion forming method of a steel anchoring flange is characterized by comprising the following steps: carrying out extrusion forming treatment on the blank obtained after the blank opening and forging to obtain a steel anchoring flange forming 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 μm.

2. The precision warm extrusion forming method of the steel anchoring flange according to claim 1, characterized in that a precision extrusion forming die of the anchoring flange is used to perform extrusion forming treatment on the blank obtained after cogging forging; wherein the step of extrusion processing comprises:

a second punching step: matching a second punching male die structure and a female die into a second punching die, further punching the anchoring flange blank with the punched holes, and punching the punched holes to obtain a steel anchoring flange forming part;

3. The method for precision warm extrusion of a steel anchoring flange according to claim 2, further comprising, before the first profiling step:

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

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 ℃.

4. The precision warm extrusion forming method of a steel anchoring flange according to claim 2 or 3, characterized in that the cavity of the female die comprises:

the device comprises a cylindrical cavity, a first end and a second end, wherein the first end and the second end are oppositely arranged; the first end of the cylindrical cavity is open and serves as the inlet end of the female die;

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

the cushion block is matched with the small end of the circular truncated cone-shaped cavity and is arranged at the small end of the circular truncated cone-shaped cavity.

5. A method for precision warm extrusion of a steel anchoring flange according to claim 4, characterized in that in the first profiling step:

preferably, the first pressing step includes:

6. The precision warm extrusion forming method of a steel anchoring flange according to claim 5, characterized in that in the second profiling step:

the anchoring flange blank comprises a flange, a first neck part in a circular truncated cone shape and a second neck part in a circular truncated cone shape; wherein the first neck portion is located on one side of the flange and the second neck portion is located on the other side of the flange; wherein the radial dimension of the flange of the anchoring flange blank is greater than the radial dimension of the flange on the blank after the first profiling; the longitudinal dimension of the flange of the anchoring flange blank is smaller than that of the flange on the blank after the first profiling; preferably, the size of the second neck portion on the anchoring flange blank is matched with the size of the large end of the first neck portion;

preferably, the second pressing step includes:

7. The precision warm extrusion forming method of a steel anchoring flange according to claim 6, characterized in that in the first punching step:

8. The precision warm extrusion forming method of a steel anchoring flange according to any one of claims 2 to 7, characterized in that the second punching step comprises:

taking the anchoring flange blank with the punched hole out of the female die, and placing a punching ring in a cavity of the female die; then placing the anchoring flange blank with the punched hole in the cavity of the female die and on the punching ring; and punching the anchoring flange blank with the punched holes for the second time by adopting a compression punch of a second punching male die structure so as to punch the punched holes to obtain a steel anchoring flange forming part.

9. The method for precision warm extrusion of a steel anchoring flange according to any one of claims 1 to 8, characterized in that the material of the blank obtained after cogging forging is CF-62 microalloyed steel; and/or

Before the step of performing extrusion forming treatment on the blank obtained after cogging forging, cogging forging is performed on a steel anchoring flange blank to prepare the blank obtained after cogging forging; wherein the average grain size of the steel anchoring flange blank is 56.9-70 μm; the true strain of the cogging forging is greater than 1.8.

10. The steel anchoring flange is characterized in that the steel anchoring flange is obtained by carrying out heat treatment on a steel anchoring flange forming piece; wherein the steel anchoring flange formed part is obtained by a precise warm extrusion forming method of the steel anchoring flange according to any one of claims 1 to 9;

preferably, the average grain size of the steel anchoring flange is 7-9 μm;

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

preferably, the heat treatment process comprises: and carrying out primary heat treatment on the steel anchoring flange forming piece at the temperature of 870 ℃ plus 940 ℃, carrying out secondary heat treatment on the steel anchoring flange forming piece subjected to the primary heat treatment at the temperature of 600 ℃ plus 660 ℃ after water cooling, and carrying out air cooling to obtain the steel anchoring flange.