阅读说明：本技术 一种盾构机刀圈异形环件的模锻制坯及轧环复合成形方法 (Die forging blank making and ring rolling composite forming method for shield machine cutter ring special-shaped ring piece ) 是由 王世超 丁学生 于杰 闫伟宁 张兰涛 蒋立 黄坤 段文华 霍达 宋冬行 于 2020-04-09 设计创作，主要内容包括：本发明公开了一种盾构机刀圈异形环件的模锻制坯及轧环复合成形方法,为获得截面形状复杂、尺寸精密,性能优异的盾构机刀圈异形环件,其技术方案为：将锯切好的合金棒材加热至始锻温度并保温,经镦粗、冲孔两道工序制备近矩形环坯；采用局部开式模锻,对近矩形环坯靠近外圆部位的上下两端面施加压力,通过局部变形得到异形预制环坯；将异形预制环坯加热至模具钢的始锻温度并保温,随后放入轧环机中,利用主辊碾轧模具以相应转速和径向进给速度对异形预制环坯进行轧环,得到盾构机刀圈异形环件。本发明的一种盾构机刀圈异形环件的模锻制坯及轧环复合成形方法不仅能最大限度的简化生产流程,降低零件的生产成本,保证环件尺寸,而且该方法保留了的完整的锻件流线,确保环件具备良好的力学性能。(The invention discloses a die forging blank making and ring rolling composite forming method of a shield machine cutter ring special-shaped ring piece, which aims to obtain the shield machine cutter ring special-shaped ring piece with complex section shape, precise size and excellent performance, and adopts the technical scheme that: heating the sawed alloy bar to the initial forging temperature, preserving heat, and preparing a nearly rectangular ring blank through two working procedures of upsetting and punching; local open die forging is adopted, pressure is applied to the upper end face and the lower end face of the part, close to the excircle, of the approximately rectangular ring blank, and the special-shaped prefabricated ring blank is obtained through local deformation; and heating the special-shaped prefabricated ring blank to the initial forging temperature of the die steel, preserving heat, then putting the special-shaped prefabricated ring blank into a ring rolling machine, and rolling the special-shaped prefabricated ring blank by using a main roller rolling die at a corresponding rotating speed and a radial feeding speed to obtain the shield machine cutter ring special-shaped ring piece. The die forging blank making and ring rolling composite forming method for the shield machine cutter ring special-shaped ring piece can simplify the production flow to the maximum extent, reduce the production cost of parts and ensure the size of the ring piece, and the method keeps the complete forging streamline and ensures that the ring piece has good mechanical properties.)

1. A die forging blank making and ring rolling composite forming method for a shield machine cutter ring special-shaped ring piece is characterized by comprising the following steps:

placing the approximately rectangular ring blank in a die for local die forging to prepare a special-shaped prefabricated ring blank;

heating the special-shaped prefabricated ring blank to 1100-1200 ℃ and preserving heat, wherein the shortest heat preservation time is not less than (0.6-0.8) min/mm multiplied by the effective section thickness of the special-shaped prefabricated ring blank; and (4) rolling the ring after the heat preservation is finished, and finally obtaining the special-shaped ring piece of the shield machine cutter ring.

2. The die forging blank making and ring rolling compound forming method for the shield tunneling machine cutter ring special-shaped ring piece according to claim 1, wherein the preparation process of the approximately rectangular ring blank comprises the following steps: sawing the alloy bar according to a preset specification, heating the sawed alloy bar to 1100-1200 ℃, and preserving heat, wherein the shortest heat preservation time = (0.6-0.8) min/mm multiplied by the diameter of the alloy bar; then upsetting and punching are carried out to manufacture a nearly rectangular ring blank.

3. The die forging blank making and ring rolling compound forming method for the shield tunneling machine cutter ring special-shaped ring piece according to claim 1, characterized in that local open die forging is adopted in the die forging process, pressure is only applied to the upper end face and the lower end face of the approximately rectangular ring blank close to the excircle part, and local deformation is carried out to obtain the special-shaped prefabricated ring blank.

4. The die forging blank-making and ring rolling compound forming method for the shield tunneling machine cutter ring special-shaped ring piece according to claim 3, characterized in that the included angle between the two inclined planes at the outer circle part of the special-shaped prefabricated ring blank is 45-60 degrees.

5. The die forging blank making and ring rolling compound forming method for the shield tunneling machine cutter ring special-shaped ring piece according to claim 3, characterized in that the maximum die forging pressure F is 7 x 10⁶N～1×10⁷N, the calculation mode is as follows: f =2 μ σ S, wherein μ is the friction coefficient of the ring material and the die, σ is the deformation resistance of the ring material at the finish forging temperature, and S is the projected area of the contact surface of the ring blank and the die.

6. The die forging blank making and ring rolling compound forming method for the shield machine cutter ring special-shaped ring piece according to claim 1, wherein in the ring rolling process, the optional rotation linear speed range of a main roller is 0.4-1.6 m/s, and the radial feeding speed of the main roller is divided into three stages: in the initial stage of ring rolling, the ring rolling stabilization stage and the ring rolling circle calibration and shaping stage, the radial feeding speed range of the main roller is 0-3 mm/s.

7. The die forging blank-making and ring-rolling composite forming method for the shield tunneling machine cutter ring special-shaped ring piece according to claim 6, characterized in that in the ring-rolling process, the maximum ring-rolling force is 5 x 10⁵N～1×10⁶N, calculated as P =2kbL (1+ h)₀/4L+m3L/8 h₀+ m3L/4b), where k is the ring material shear yield strength, b is the ring height, L is the contact arc length, h₀Is the wall thickness of the ring member, and m is the friction factor.

8. The die forging blank making and ring rolling compound forming method for the shield machine cutter ring special-shaped ring piece according to claim 1, wherein the rolling ratio lambda of actual forming of the shield machine cutter ring special-shaped ring piece is 1-2.

9. The die forging blank-making and ring-rolling composite forming method for the shield tunneling machine cutter ring special-shaped ring piece according to any one of claims 1-8, characterized in that the cutter ring is made of die steel.

Technical Field

The invention belongs to the technical field of forging, and particularly relates to a die forging blank making and ring rolling composite forming method for a shield machine cutter ring special-shaped ring piece.

Background

A cutter ring of a shield machine belongs to a special-shaped ring piece and is a key part for breaking rocks and chiseling in the tunneling process of the shield machine. In the working process of the shield tunneling machine, the cutter ring is easy to damage due to the fact that the cutter ring is always subjected to the abrasion and impact action of rocks, and the brand new cutter ring needs to be frequently replaced to meet the working requirement of the shield tunneling machine. Therefore, the manufacturing and forming technology of the shield machine cutter ring, which has simple and convenient process, low cost and easy mass production, is scheduled. At present, the domestic main forming method of the cutter ring comprises the following steps: integral open die forging or closed die forging forming, free forging of a nearly rectangular ring blank, direct multiple ring rolling forming, rolling of the rectangular ring blank and large-allowance machining forming. These methods are often influenced by factors such as the production cost of parts, comprehensive mechanical properties and dimensional requirements, and the expected ideal effect is difficult to achieve.

The integral open die forging or closed die forging is adopted for forming, the size precision of parts is higher, but the deformation resistance of materials in a pre-forging die impression and a finish forging die impression in the forming process is large, the required tonnage of equipment is large, the die impressions are easy to lose effectiveness due to abrasion or cracking, the service life is short, and the production cost is high. The trimming process after the integral open die forging can damage the integrity of a metal streamline of the forge piece, thereby influencing the mechanical property of the forge piece.

The method adopts freely forged nearly rectangular ring blanks and then directly carries out ring rolling forming for multiple times, the process is simple, but the number of ring rolling fire times becomes a 'double-edged sword' which restricts the dimensional precision and the mechanical property of parts, the ring rolling fire times are few, the special-shaped part of the outer diameter of the ring piece is difficult to completely fill a rolling die, and the dimensional requirement of a final product cannot be ensured; the ring is hot, which can easily cause the defects of coarse crystal grain, damage and crack of the forging, and increase the economic cost.

The process is simple, but the material utilization rate is low and the economic benefit is low. In addition, the machining seriously damages the integrity of the metal streamline of the forging and reduces the mechanical property of the part.

The Chinese patent with publication number CN101279343A discloses a rolling and forming method of stainless steel deformed ring forgings, which comprises the steps of primarily rolling punched round cake forgings by 40-45% of deformation to obtain rectangular ring blanks, and secondarily rolling and forming the rectangular ring blanks by a ring rolling machine in combination with a rolling die. The ring rolling process has the problems of multiple rolling fire and long production period, and in addition, the metal flow of the rectangular ring blank in the rolling pass is complex, the problem of incomplete filling of the rolling die is easily caused in the process of rolling the special-shaped ring, and the size of a part is difficult to ensure.

For another example, chinese patent publication No. CN103100621 discloses a rolling forming method for a structural steel complex irregular cross-section ring member, which comprises heating a metal bar, upsetting, punching, and ring-rolling into a rectangular ring blank, combining an inner ring module and an outer ring module to first prepare a irregular pre-rolled blank having a shape opposite to that of a finish-rolled irregular ring structure, and then rolling into an irregular cross-section ring member through the inner ring module and the outer ring module. The method can overcome the problem of incomplete mold filling during rolling of the rectangular ring blank, and the ring piece with high dimensional precision is rolled. However, the method needs frequent replacement of the rolling die, repeated rolling for many times invisibly increases economic cost, and is easy to cause defects of coarse grains, rolling damage, rolling cracks and the like of the structure of the forge piece.

Therefore, the invention discloses a die forging blank making and ring rolling composite forming method for a shield machine cutter ring special-shaped ring piece.

Disclosure of Invention

The invention aims to provide a die forging blank making and ring rolling composite forming method for a special-shaped ring piece of a shield machine cutter ring. The method not only saves the process investment and the raw material consumption, does not need to rely on a die cavity with short service life and high cost, but also can ensure the streamline integrity of the forge piece to the maximum extent and ensure the mechanical property of the final product.

In order to achieve the purpose, the technical scheme of the die forging blank making and ring rolling composite forming method for the special-shaped ring piece of the shield machine cutter ring comprises the steps of preparing a nearly rectangular ring blank, preparing a special-shaped prefabricated ring blank and rolling a ring.

Further, the preparation of the near-rectangular ring blank comprises the following steps: sawing, heating, upsetting and punching.

The sawing step comprises the following steps: and sawing the alloy bar according to the preset specification.

The heating step is as follows: heating the sawed alloy bar to the initial forging temperature of 1100-1200 ℃, and preserving heat, wherein the shortest heat preservation time is not = 0.6-0.8 min/mm multiplied by the diameter of the alloy bar;

the upsetting step comprises the following steps: and (3) using a press machine, and upsetting the whole body to H = 100-120 mm after eliminating sharp corners by riveting and upsetting.

Furthermore, in order to avoid the temperature rise of the material caused by excessive deformation, the deformation during upsetting is controlled to be 30-60 percent.

The punching step comprises the following steps: punching phi 120-135 mm by using a punch, wherein the thickness of a punching bottom sheet is less than or equal to 45mm, and preparing the nearly rectangular ring piece.

Further, the preparation of the special-shaped prefabricated ring blank comprises the following steps: and local die forging.

The local die forging step is as follows: open die forging is adopted on a press, a nearly rectangular ring blank is placed into a preheated die, pressure is only applied to the upper end surface and the lower end surface of the nearly rectangular ring blank close to the excircle, and local deformation is carried out to prepare a special-shaped prefabricated ring blank;

further, the included angle of the two inclined planes at the excircle part of the special-shaped prefabricated ring blank is 45-60 degrees;

further, the maximum die forging pressure F was 7X 10⁶N～1×10⁷N；

Further, the maximum die forging pressure is calculated in the following manner: f =2 μ σ S, wherein μ is the friction coefficient of the ring material and the die, σ is the deformation resistance of the ring material at the finish forging temperature, and S is the projected area of the contact surface of the ring blank and the die.

Further, the rolling ring comprises: heating and rolling.

The heating step is as follows: heating the special-shaped prefabricated ring blank to the initial forging temperature of 1100-1200 ℃, and preserving heat, wherein the shortest heat preservation time = (0.6-0.8) min/mm multiplied by the effective section thickness of the special-shaped prefabricated ring blank;

the rolling step comprises the following steps: and (3) placing the heated special-shaped prefabricated ring blank on a ring rolling machine, enabling the outer convex part of the special-shaped prefabricated ring blank to correspond to the inner concave part of the main roller die, and rolling the special-shaped prefabricated ring blank to the required size and shape by the main roller die at a certain axial rotating speed and radial feeding speed.

Further, the optional axial rotation linear velocity range of the main roller is 0.4-1.6 m/s, and the radial feeding velocity of the main roller is divided into three stages: in the initial stage of ring rolling, the ring rolling stabilization stage and the ring rolling circle calibration and shaping stage, the radial feed speed range is 0-3 mm/s.

Further, in the initial ring rolling stage, the main roller sends the special-shaped prefabricated ring blank into a ring rolling die through radial feed motion, so that the blank is ensured to be in contact with the die and the ring rolling is started; in the ring rolling stabilization stage, the radial feed motion and the axial rotation motion of a main roller are combined to ensure that the special-shaped prefabricated ring blank is continuously and stably filled in a ring rolling die; and in the ring rolling and rounding stage, the main roller does not perform radial feeding motion, only performs axial rotation motion, and rounds the ring piece, so that the size precision of the final ring piece is ensured.

Furthermore, in the ring rolling process, the maximum ring rolling force is 5 multiplied by 10⁵N～1×10⁶N。

Further, the maximum ring rolling force was calculated in a manner of P =2kbL (1+ h)₀/4L+m3L/8 h₀+ m3L/4b), where k is the ring material shear yield strength, b is the ring height, L is the contact arc length, h₀Is the wall thickness of the ring member, and m is the friction factor.

Further, the actual forming deformation is the rolling ratio lambda of the sectional area of the intermediate blank of the ring blank after the open die forging local deformation to the sectional area of the final ring piece.

The invention discloses a local die forging blank making and ring rolling composite forming method of a shield machine cutter ring special-shaped ring piece, which adopts the technical scheme of saw cutting, heating, upsetting, punching, die forging and ring rolling.

Compared with the prior art, the invention has the following advantages: large allowance machining is not needed, no trimming step is needed, the material utilization rate is improved to the maximum extent, and the integrity of a forging flow line is reserved; multiple ring rolling is not needed, and the special-shaped prefabricated ring blank prepared by local die forging can be completely filled in a ring rolling die; the process is simple, complex forging impression and large-tonnage complex forming equipment are not needed, the cost of the forge piece is saved, and the technology is suitable for various enterprises.

Drawings

The invention is further described with reference to the following figures and specific embodiments.

FIG. 1 is a schematic view of partial swaging in the present invention; wherein: 1. an upper die; 2. a nearly rectangular ring blank; 3. a lower die;

FIG. 2 is a schematic view of a partially swaged profiled preform in accordance with the present invention;

fig. 3 is a schematic view of a main roll rolling mold according to the present invention.

FIG. 4 is a schematic view of the filling of the special-shaped preform ring shown in FIG. 2, rolled in the rolling die of FIG. 4. Wherein: 6. an upper shoulder; 7. a lower shoulder; 8. an upper inclined plane of the special-shaped prefabricated ring blank; 9. a lower inclined plane of the special-shaped prefabricated ring blank; 10. a V-shaped groove is arranged; 11. a V-shaped groove is arranged; 12. internal U-shaped groove

Fig. 5 is a schematic view of the final special-shaped ring piece after the ring rolling forming of the invention.

Detailed Description

Example 1

In this example, the specific implementation of the method is described in detail by taking alloy number H13E as an example:

the H13E alloy has the following main chemical element contents:

TABLE 1 content of main chemical elements of H13E alloy

Element(s)

C

Cr

Si

Mn

V

Mo

Ni

Content (%)

0.49～0.53

4.80～5.10

0.80～1.10

0.20～0.40

0.80～1.20

1.25～1.45

≤0.25

Element(s)

S

P

N

O

H

Fe

Content (%)

≤0.005

≤0.010

≤0.007

≤0.0015

≤0.0002

Balance of

A method for implementing local die forging blank making and ring rolling composite forming of a shield machine cutter ring special-shaped ring piece needs to provide a band sawing machine, a forging heating furnace, a press machine, a ring rolling machine and a manipulator.

The invention discloses a die forging blank making and ring rolling composite forming method of a shield machine cutter ring special-shaped ring piece, which adopts the following technical scheme that the method comprises the following steps: preparing a nearly rectangular ring blank, preparing a special-shaped prefabricated ring blank, and rolling a ring.

Further, the preparation of the near-rectangular ring blank comprises the following steps: sawing, heating, upsetting and punching.

The sawing step comprises the following steps: and sawing the H13E alloy bar according to the preset specification.

The heating step is as follows: and heating the sawed H13E alloy bar to the initial forging temperature of 1170 ℃, and preserving the heat, wherein the shortest preserving time =0.6min/mm multiplied by the diameter of the H13E alloy bar of 175 mm.

The upsetting step comprises the following steps: and (4) using a press, and upsetting the whole body to H =100 +/-5 mm after eliminating sharp corners by riveting and upsetting.

Furthermore, in order to avoid the temperature rise of H13E caused by excessive deformation, the deformation amount during upsetting is controlled to be 40-45%.

The punching step comprises the following steps: punching with a punch until the diameter is 130 +/-5 mm and the thickness of a punching bottom sheet is 35mm to prepare the H13E alloy near-rectangular ring 2.

Further, the preparation of the special-shaped prefabricated ring blank comprises the following steps: and local die forging.

The local die forging step is as follows: as shown in figure 1, open die forging is adopted on a press, a nearly rectangular ring blank 2 is placed between a preheated upper die 1 and a preheated lower die 3, pressure is applied to only the upper end surface and the lower end surface of the nearly rectangular ring blank 2 close to the excircle part, and H13E special-shaped prefabricated ring blank 4 is formed through local deformation.

Further, the included angle alpha of the two inclined planes at the excircle part of the H13E special-shaped precast ring blank 4 is 50 degrees;

further, the maximum die forging pressure F was 7.69X 10⁶N；

Further, the maximum die forging pressure is calculated in the following manner: f =2 μ σ S, wherein μ is the friction coefficient of the H13E alloy ring material and the die, μ =0.24, σ is the deformation resistance of H13E at the finish forging temperature of 900 ℃, σ =295MPa, S is the projection area of the contact surface of the ring blank 2 and the die 1, and S =543.1cm²。

The local open die forging has the following process characteristics:

the forging flow lines generated in the special-shaped prefabricated ring blank are distributed along the contour of the forging piece along the shape, so that the comprehensive mechanical property of the ring blank is favorably improved; the special-shaped prefabricated ring blank has no burrs, trimming is not needed in later processing, and the material utilization rate is high; only local deformation of the nearly rectangular ring blank is realized, the die is simple, the tonnage of required equipment is small, and the production cost is low.

The local open die forging can obviously reduce the deformation resistance in the forging process, reduce the dependence on large-tonnage die forging equipment, quickly obtain the special-shaped prefabricated ring blank which can ensure the size and the quality requirements of the final rolled ring, and has low production cost and high production efficiency. The local open die forging does not damage the integrity of a forging streamline, so that the ring rolling forming quality and the batch stability of the ring piece are high.

Further, the rolling ring comprises: heating and rolling.

The heating step is as follows: heating the special-shaped prefabricated ring blank 4 to the initial forging temperature of 1170 ℃, and preserving heat, wherein the shortest heat preservation time =0.6min/mm multiplied by the effective section thickness of the special-shaped prefabricated ring blank of 88 mm;

the rolling step comprises the following steps: and (3) placing the heated special-shaped prefabricated ring blank 4 on a ring rolling machine, enabling the external convex part of the special-shaped prefabricated ring blank 4 to correspond to the internal concave part of the main roller die 5, and rolling the special-shaped prefabricated ring blank 4 to the required shape and size by combining the axial rotation linear speed of 1.4m/s and the radial feeding speed of 1mm/s of the main roller die 5.

Further, in the ring rolling process, the process of gradually filling the main roll mold of the ring rolling machine with metal through plastic deformation is shown in fig. 4. In the initial stage of ring rolling, as shown in fig. 4a, the main roller feeds the special-shaped prefabricated ring blank 4 into the rolling main roller die 5 through radial feed motion, the blank contacts with the die and starts to roll the ring, and the upper shoulder 6 and the lower shoulder 7 of the main roller die 5 respectively extrude the upper inclined surface 8 and the lower inclined surface 9 of the special-shaped prefabricated ring blank 4. According to the principle that the volume of metal is not changed in plastic deformation and the law of minimum resistance, along with the gradual increase of the diameter of the ring blank, the metal at the upper inclined surface 8 and the lower inclined surface 9 of the special-shaped prefabricated ring blank 4 flows to the axial and radial vacant areas in the main roller mold 5; in the ring rolling stabilization stage, as shown in fig. 4b and 4c, the radial feed motion of the main roller is combined with the axial rotation motion, the special-shaped prefabricated ring blank 4 firstly completes the filling of an upper V-shaped groove 10 and a lower V-shaped groove 11 outside an upper shoulder 6 and a lower shoulder 7 in the main roller mold 5, and then completes the filling of a U-shaped groove 12 inside the upper shoulder 6 and the lower shoulder 7 in the main roller mold 5; and (3) rolling a ring to round and shape, wherein the rolling ring is not subjected to radial feed motion and is only subjected to axial autorotation motion, the ring is subjected to round and shape correction, and finally the special-shaped ring of the shield machine cutter ring shown in figure 5 is obtained.

Furthermore, in the ring rolling process, the maximum ring rolling force is 6.9 multiplied by 10⁵N。

Further, the maximum ring rolling force was calculated in a manner of P =2kbL (1+ h)₀/4L+m3L/8 h₀+ m3L/4b), where k is the ring material shear yield strength, k =170.3MPa, b is the ring height, b =90mm, L is the contact arc length, L =1.54mm, h₀Is the wall thickness of the ring member, h₀=83.75mm, m being the friction factor, m = 0.6.

Further, the actual forming deformation is the rolling ratio lambda of the sectional area of the intermediate blank of the ring blank after the open die forging local deformation to the sectional area of the final ring piece. In this embodiment, the cross-sectional area of the intermediate blank of the ring blank after the local die forging deformation is 7646mm²The sectional area of the final ring piece is 5034 mm²And λ is 1.52.

The invention discloses a local die forging blank making and ring rolling composite forming method of a shield machine cutter ring, which adopts the technical scheme of sawing, heating, upsetting, punching, die forging and ring rolling.

Compared with the prior art, the invention has the following advantages: large allowance machining is not needed, no trimming step is needed, the material utilization rate is improved to the maximum extent, and the integrity of a forging flow line is reserved; multiple ring rolling is not needed, and the special-shaped prefabricated ring blank prepared by local die forging can be completely filled in a ring rolling die; the process is simple, complex forging impression and large-tonnage complex forming equipment are not needed, the cost of the forge piece is saved, and the technology is suitable for various enterprises.

Therefore, the die forging and ring rolling composite forming method for the shield machine cutter ring special-shaped ring piece can effectively simplify the process flow, can manufacture the shield machine cutter ring special-shaped ring piece with excellent mechanical property by using a low-cost process method and low-cost equipment, has wide application prospect, and is suitable for popularization in various enterprises.

Example 2

In this example, the specific implementation of the method is described in detail by taking an alloy with a grade of 4Cr5MoSiV1 as an example:

the main chemical element contents of the 4Cr5MoSiV1 alloy are as follows:

TABLE 2.4 main chemical elements of Cr5MoSiV1 alloy

Element(s)

C

Cr

Si

Mn

V

Mo

Ni

Content (%)

0.32～0.45

4.75～5.50

0.80～1.20

0.20～0.50

0.80～1.20

1.10～1.75

≤0.25

Element(s)

S

P

Fe

Content (%)

≤0.030

≤0.030

Balance of

The method for implementing the local die forging blank making and ring rolling composite forming of the shield machine cutter ring special-shaped ring piece needs to provide a band sawing machine, a forging heating furnace, a press machine, a ring rolling machine and a manipulator.

The invention discloses a die forging blank making and ring rolling composite forming method for a shield machine cutter ring special-shaped ring piece.

Further, the preparation of the near-rectangular ring blank comprises the following steps: sawing, heating, upsetting and punching.

The sawing step comprises the following steps: sawing the 4Cr5MoSiV1 alloy bar according to the preset specification.

The heating step is as follows: heating the sawed 4Cr5MoSiV1 alloy bar to the initial forging temperature of 1150 ℃ and preserving heat, wherein the shortest heat preservation time =0.6min/mm multiplied by 4Cr5MoSiV1 alloy bar diameter of 175 mm;

the upsetting step comprises the following steps: and using a press, and upsetting the whole body to H =105 +/-5 mm after eliminating sharp corners by riveting and upsetting.

Furthermore, in order to avoid the temperature rise of 4Cr5MoSiV1 caused by excessive deformation, the deformation amount during upsetting is controlled to be 40-45%.

The punching step comprises the following steps: punching phi 125 +/-5 mm by using a punch, and punching the bottom sheet to be 35mm in thickness to prepare the 4Cr5MoSiV1 approximately-rectangular ring piece 2.

Further, the preparation of the special-shaped prefabricated ring blank comprises the following steps: and local die forging.

The local die forging step is as follows: as shown in figure 1, open die forging is adopted on a press, a rectangular ring blank 2 is placed between a preheated upper die 1 and a preheated lower die 3, pressure is applied to the upper end surface and the lower end surface of the rectangular ring blank 2 close to the excircle part, and local deformation is carried out to prepare a 4Cr5MoSiV1 special-shaped prefabricated ring blank 4.

Furthermore, the included angle alpha of two inclined planes at the excircle part of the 4Cr5MoSiV1 special-shaped prefabricated ring blank is 55 degrees;

further, the maximum die forging pressure F was 7.157X 10⁶N；

Further, the maximum die forging pressure is calculated in the following manner: f =2 μ σ S, where μ is the coefficient of friction of the 4Cr5MoSiV1 ring material with the die, μ =0.24, σ is the deformation resistance of 4Cr5MoSiV1 at the finish forging temperature of 900 ℃, σ =290MPa, S is the projected area of the contact surface of the ring blank 2 and the die 1, and S =514.19cm²。

The local open die forging has the following process characteristics:

the forging flow lines generated in the special-shaped prefabricated ring blank are distributed along the contour of the forging piece along the shape, so that the comprehensive mechanical property of the ring blank is favorably improved; the special-shaped prefabricated ring blank has no burrs, trimming is not needed in later processing, and the material utilization rate is high; only local deformation is carried out on the rectangular ring blank, the die is simple, the tonnage of required equipment is small, and the production cost is low.

The local open die forging can obviously reduce the material deformation resistance in the forging process, reduce the dependence on large-tonnage die forging equipment, quickly obtain the special-shaped prefabricated ring blank which can ensure the size and the quality of the final rolled ring, and has low production cost and high production efficiency. The local open die forging does not damage the integrity of a forging streamline, so that the ring rolling forming quality and the batch stability of the ring piece are high.

Further, the rolling ring comprises: heating and rolling.

The heating step is as follows: heating the special-shaped prefabricated ring blank 4 to the initial forging temperature of 1150 ℃ and preserving heat, wherein the shortest heat preservation time =0.6min/mm multiplied by 4Cr5MoSiV1 effective section thickness of the special-shaped prefabricated ring blank is 90 mm;

the ring rolling step comprises: and (3) placing the heated special-shaped prefabricated ring blank 4 on a ring rolling machine, enabling the external convex part of the special-shaped prefabricated ring blank 4 to correspond to the internal concave part of the main roller mold 5, and rolling the special-shaped prefabricated ring blank 4 to the required shape and size by combining the axial rotation linear speed of 1.5m/s and the radial feeding speed of 1.6 mm/s of the main roller mold 5.

Further, in the ring rolling process, the process of gradually filling the main roll mold of the ring rolling machine with metal through plastic deformation is shown in fig. 4. In the initial stage of ring rolling, as shown in fig. 4a, the main roller feeds the special-shaped prefabricated ring blank 4 into the rolling main roller die 5 through radial feed motion, the blank contacts with the die and starts to roll the ring, and the upper shoulder 6 and the lower shoulder 7 of the main roller die 5 respectively extrude the upper inclined surface 8 and the lower inclined surface 9 of the special-shaped prefabricated ring blank 4. According to the principle that the volume of metal is not changed in plastic deformation and the law of minimum resistance, along with the gradual increase of the diameter of the ring blank, the metal at the upper inclined surface 8 and the lower inclined surface 9 of the special-shaped prefabricated ring blank 4 flows to the axial and radial vacant areas in the main roller mold 5; in the ring rolling stabilization stage, as shown in fig. 4b and 4c, the radial feed motion of the main roller is combined with the axial rotation motion, the special-shaped prefabricated ring blank 4 firstly completes the filling of an upper V-shaped groove 10 and a lower V-shaped groove 11 outside an upper shoulder 6 and a lower shoulder 7 in the main roller mold 5, and then completes the filling of a U-shaped groove 12 inside the upper shoulder 6 and the lower shoulder 7 in the main roller mold 5; and (3) rolling a ring to round and shape, wherein the rolling ring is not subjected to radial feed motion and is only subjected to axial autorotation motion, the ring is subjected to round and shape correction, and finally the special-shaped ring of the shield machine cutter ring shown in figure 5 is obtained.

Further, in the ring rolling process, the most important isThe large ring rolling force is 7.74 multiplied by 10⁵N。

Further, the maximum ring rolling force was calculated in a manner of P =2kbL (1+ h)₀/4L+m3L/8 h₀+ m3L/4b), where k is the ring material shear yield strength, k =167.43MPa, b is the ring height, b =88mm, L is the contact arc length, L = 2mm, h₀Is the wall thickness of the ring member, h₀=97mm, m is the friction factor, m = 0.6.

Further, the actual forming deformation is the rolling ratio lambda of the sectional area of the intermediate blank of the ring blank after the open die forging local deformation to the sectional area of the final ring piece. In this example, the sectional area of the intermediate blank of the ring blank after the local die forging deformation was 9284mm²The sectional area of the final ring piece is 5913 mm²And λ is 1.57.

The invention discloses a local die forging blank making and ring rolling composite forming method of a shield machine cutter ring, which adopts the technical scheme of sawing, heating, upsetting, punching, die forging and ring rolling.

Compared with the prior art, the invention has the following advantages: large allowance machining is not needed, no trimming step is needed, the material utilization rate is improved to the maximum extent, and the integrity of a forging flow line is reserved; multiple ring rolling is not needed, and the special-shaped prefabricated ring blank prepared by local die forging can be completely filled in a ring rolling die; the process is simple, complex forging impression and large-tonnage complex forming equipment are not needed, the cost of the forge piece is saved, and the technology is suitable for various enterprises.

Therefore, the die forging and ring rolling composite forming method for the shield machine cutter ring special-shaped ring piece can effectively simplify the process flow, can manufacture the shield machine cutter ring special-shaped ring piece with excellent mechanical property by using a low-cost process method and low-cost equipment, has wide application prospect, and is suitable for popularization in various enterprises.

Example 3

In this embodiment, the specific implementation of the method is described in detail by taking alloy with the designation of C118 as an example:

the main chemical element contents of the C118 alloy are as follows:

TABLE 3 main chemical element content of C118 alloy

Element(s)

C

Cr

Si

Mn

V

Mo

Ni

Content (%)

0.65～0.78

4.80～5.20

0.15～0.50

0.30～0.65

0.40～0.60

2.20～2.40

≤0.25

Element(s)

S

P

N

O

H

Fe

Content (%)

≤0.01

≤0.015

≤0.007

≤0.0015

≤0.0002

Balance of

The method for implementing the local die forging blank making and ring rolling composite forming of the shield machine cutter ring special-shaped ring piece needs to provide a band sawing machine, a forging heating furnace, a press machine, a ring rolling machine and a manipulator.

The invention discloses a die forging blank making and ring rolling composite forming method for a shield machine cutter ring special-shaped ring piece.

Further, the preparation of the near-rectangular ring blank comprises the following steps: sawing, heating, upsetting and punching.

The sawing step comprises the following steps: and sawing the C118 alloy bar according to the preset specification.

The heating step is as follows: heating the sawed C118 alloy bar to the initial forging temperature of 1200 ℃ and preserving heat, wherein the shortest heat preservation time =0.8min/mm multiplied by the diameter of the alloy bar of 195 mm;

the upsetting step comprises the following steps: and using a press, and upsetting the whole body to H =110 +/-5 mm after eliminating sharp corners by riveting and upsetting.

Furthermore, in order to avoid the temperature rise of the C118 alloy caused by excessive deformation, the deformation amount during upsetting is controlled to be 40-45%.

The punching step comprises the following steps: punching phi 125 +/-5 mm by using a punch, and punching the bottom plate to be 40mm in thickness to prepare the C118 alloy near-rectangular ring 2.

Further, the preparation of the special-shaped prefabricated ring blank comprises the following steps: and local die forging.

The local die forging step is as follows: as shown in figure 1, open die forging is adopted on a press, a rectangular ring blank 2 is placed between a preheated upper die 1 and a preheated lower die 3, pressure is applied to the upper end surface and the lower end surface of the rectangular ring blank 2 close to the excircle part, and local deformation is carried out to prepare a C118 alloy special-shaped prefabricated ring blank 4.

Further, the included angle alpha of the two inclined planes at the excircle part of the C118 alloy special-shaped precast ring blank 4 is 56 degrees;

further, the maximum die forging pressure F was 9.23X 10⁶N；

Further, the maximum die forging pressure is calculated in the following manner: f =2 μ σ S, wherein μ is the friction coefficient of the C118 alloy ring material and the die, μ =0.24, σ is the deformation resistance of the C118 alloy at the finish forging temperature of 900 ℃, is σ =305MPa, S is the projection area of the contact surface of the ring blank 2 and the die 1, and S =630.61cm²。

The local open die forging has the following process characteristics:

the forging flow lines generated in the special-shaped prefabricated ring blank are distributed along the contour of the forging piece along the shape, so that the comprehensive mechanical property of the ring blank is favorably improved; the special-shaped prefabricated ring blank has no burrs, trimming is not needed in later processing, and the material utilization rate is high; only local deformation is carried out on the rectangular ring blank, the die is simple, the tonnage of required equipment is small, and the production cost is low.

The local open die forging can obviously reduce the material deformation resistance in the forging process, reduce the dependence on large-tonnage die forging equipment, quickly obtain the special-shaped prefabricated ring blank which can ensure the size and the quality of the final rolled ring, and has low production cost and high production efficiency. The local open die forging does not damage the integrity of a forging streamline, so that the ring rolling forming quality and the batch stability of the ring piece are high.

Further, the rolling ring comprises: heating and rolling.

The heating step is as follows: heating the special-shaped prefabricated ring blank 4 to the initial forging temperature of 1200 ℃ and preserving heat, wherein the shortest heat preservation time =0.8min/mm multiplied by the effective section thickness of the special-shaped prefabricated ring blank of 102 mm;

the rolling step comprises the following steps: and (3) placing the heated special-shaped prefabricated ring blank 4 on a ring rolling machine, enabling the external convex part of the special-shaped prefabricated ring blank 4 to correspond to the internal concave part of the main roller mold 5, and rolling the special-shaped prefabricated ring blank 4 to the required shape and size by combining the axial rotation linear speed of 1.2m/s and the radial feeding speed of 0.8 mm/s of the main roller mold 5.

Further, in the ring rolling process, the process of gradually filling the main roll mold of the ring rolling machine with metal through plastic deformation is shown in fig. 4. In the initial stage of ring rolling, as shown in fig. 4a, the main roller feeds the special-shaped prefabricated ring blank 4 into the rolling main roller die 5 through radial feed motion, the blank contacts with the die and starts to roll the ring, and the upper shoulder 6 and the lower shoulder 7 of the main roller die 5 respectively extrude the upper inclined surface 8 and the lower inclined surface 9 of the special-shaped prefabricated ring blank 4. According to the principle that the volume of metal is not changed in plastic deformation and the law of minimum resistance, along with the gradual increase of the diameter of the ring blank, the metal at the upper inclined surface 8 and the lower inclined surface 9 of the special-shaped prefabricated ring blank 4 flows to the axial and radial vacant areas in the main roller mold 5; in the ring rolling stabilization stage, as shown in fig. 4b and 4c, the radial feed motion of the main roller is combined with the axial rotation motion, the special-shaped prefabricated ring blank 4 firstly completes the filling of an upper V-shaped groove 10 and a lower V-shaped groove 11 outside an upper shoulder 6 and a lower shoulder 7 in the main roller mold 5, and then completes the filling of a U-shaped groove 12 inside the upper shoulder 6 and the lower shoulder 7 in the main roller mold 5; and (3) rolling a ring to round and shape, wherein the rolling ring is not subjected to radial feed motion and is only subjected to axial autorotation motion, the ring is subjected to round and shape correction, and finally the special-shaped ring of the shield machine cutter ring shown in figure 5 is obtained.

Furthermore, in the ring rolling process, the maximum ring rolling force is 8.42 multiplied by 10⁵N。

Further, the maximum ring rolling force was calculated in a manner of P =2kbL (1+ h)₀/4L+m3L/8 h₀+ m3L/4b), where k is the ring material shear yield strength, k =176.09MPa, b is the ring height, b =102mm, L is the contact arc length, L =1.55mm, h₀Is the wall thickness of the ring member, h₀=87.5mm, m is the friction factor, m = 0.6.

Further, the actual forming deformation is the rolling ratio lambda of the sectional area of the intermediate blank of the ring blank after the open die forging local deformation to the sectional area of the final ring piece. In this example, the ring blank after the local die forging deformationThe cross section of the intermediate blank is 9922mm²The sectional area of the final ring piece is 5827 mm²And λ is 1.7.

The invention discloses a local die forging blank making and ring rolling composite forming method of a shield machine cutter ring, which adopts the technical scheme of sawing, heating, upsetting, punching, die forging and ring rolling.

Compared with the prior art, the invention has the following advantages: large allowance machining is not needed, no trimming step is needed, the material utilization rate is improved to the maximum extent, and the integrity of a forging flow line is reserved; multiple ring rolling is not needed, and the special-shaped ring preform prepared by local die forging can be completely filled in a ring rolling die; the process is simple, complex forging impression and large-tonnage complex forming equipment are not needed, the cost of the forge piece is saved, and the technology is suitable for various enterprises.

Therefore, the die forging and ring rolling composite forming method for the shield machine cutter ring special-shaped ring piece can effectively simplify the process flow, can manufacture the shield machine cutter ring special-shaped ring piece with excellent mechanical property by using a low-cost process method and low-cost equipment, has wide application prospect, and is suitable for popularization in various enterprises.

The foregoing examples and description merely illustrate the principles of the present invention and are not intended to limit the scope of the method. For the special-shaped ring forgings with different shapes, special-shaped ring pieces with different cross-sectional shapes can be prepared only by changing the shape of a die cavity of a local die forging and the shape of a ring rolling die. Various non-inventive changes and modifications related to the present invention are within the scope of the present invention.