CN111282996A

CN111282996A - Piercing-rolling integrated four-section type composite top

Info

Publication number: CN111282996A
Application number: CN202010271291.3A
Authority: CN
Inventors: 冯永涛; 冯永青; 冯梓轩; 吴慧琴
Original assignee: 冯永涛
Priority date: 2020-04-08
Filing date: 2020-04-08
Publication date: 2020-06-16

Abstract

The invention relates to a seamless tube rolling technology in the rolling forming process of nonferrous metal and ferrous metal, in particular to a piercing-rolling integrated four-section type composite top head which comprises a nose part (5), a cone body and a straight section, wherein the cone body comprises a section I, a section II and a section III which are smoothly connected in sequence, the β angle of the section I is 3-4 degrees, the β angle of the section II is 5.3-7.2 degrees, the β angle of the section III is 4.38-5.2 degrees, the outer edge of the straight section is the maximum diameter of the top head, the length ratio of the section I, the section II, the section III and the straight section is 1.4: 3.0: 2.4: 1.0-1.04 degrees, the four-section type composite top head is more suitable for metal deformation, the phenomenon that the top head is connected and rolled and cannot be bitten due to the fact that the center is not loosened in the process of producing a seamless tube by a piercing-rolling technology is avoided, and the problem that the rolling of the inner surface of a tube body cannot be rolled and the tail block and rolled smoothly.

Description

Piercing-rolling integrated four-section type composite top

Technical Field

The invention relates to a seamless tube rolling technology in the process of rolling and forming nonferrous metal and ferrous metal, mainly relates to the design and manufacture of tools and dies made of materials such as zirconium, niobium, titanium, Tc4, Ti80 and the like, and particularly relates to a four-section type piercing-rolling integrated composite plug.

Background

The production of traditional hot-rolled seamless pipe mainly relates to ferrous metal calendering and forming, the technological tool does not have the condition for producing and rolling nonferrous metal, through researching and summarizing traditional rolling technological process and tool design for many years, technological parameters and tool design are optimized on the basis of ferrous metal calendering and forming, so that the technological route for rolling nonferrous metal by using traditional mode is realized, the nonferrous metal is integrated in piercing and rolling, fixed technology and piercing, rolling and fixed technology in the thermoplastic deformation process, the method is suitable for rolling nonferrous metal materials such as zirconium, niobium, titanium, Tc4 and Ti80, and the piercing and rolling integrated four-section type composite top realizes piercing and rolling solid blank of nonferrous metal into hollow blank pipe, so that inner surface spiral lines are uniformly eliminated. The specification and diameter of the plug are designed within the range of phi 48mm to 409mm, and the specification range of a perforated capillary tube with the plug length of 85 mm to 970mm for producing nonferrous metals is within the range of phi 52 mm to phi 520 x 8mm to 45mm, and the length range of the capillary tube is 5m to 10.5 m; the diameter range of a suitable blank is phi 80-450 mm, the length range of the blank is 2.5-4 m, and the specification of a finished product is phi 60-phi 477 multiplied by 4-38 mm to form a finished product pipe 6-12.5 m.

The design structure of the common hot-rolling piercing plug is mostly a two-end type or three-section type structure, the design appearance of the conventional piercing plug is not suitable for rolling of nonferrous metals, such as zirconium, niobium, titanium, Tc4, Ti80 and other materials, the quality of the inner surface cannot be guaranteed, and stable rolling cannot be realized. The plug is designed to be a disposable piercing application plug which can not be reused, and the application cost of the plug tool is high.

Disclosure of Invention

In order to solve the problems, the invention provides a piercing-rolling integrated four-section composite plug which is more suitable for metal deformation, avoids the phenomena of sticking the plug and not biting in rolling caused by no loose center in the process of producing a non-ferrous metal seamless tube by a piercing and skew rolling process, and solves the problem that smooth rolling cannot be realized by rolling and folding the inner surface of a tube body and a middle clamp and a tail clamp in rolling. The technical scheme adopted by the invention is as follows:

a piercing-rolling integrated four-section type composite plug comprises a nose part (5), a cone body and a straight section, wherein the cone body comprises a section I, a section II and a section III which are connected smoothly in sequence, the β angle of the section I is 3-4 degrees, the β angle of the section II is 5.3-7.2 degrees, the β angle of the section III is 4.38-5.2 degrees, the outer edge of the straight section is a cylindrical surface and is the maximum diameter of the plug, and the length ratio of the section I, the section II, the section III to the straight section is 1.4: 3.0: 2.4: 1.0-1.04.

The penetrating and rolling integrated four-section type composite plug is characterized in that the β angle of the section I is 3-4 degrees, the β angle of the section II is 5.3-7.2 degrees, and the β angle of the section III is 4.3-5.2 degrees.

The matrix hardness of the piercing-rolling integrated four-section composite plug is not lower than 230 HBW; the plug is processed by an oxidation heat treatment process, the thickness of an inner layer oxidation layer of the plug after the oxidation heat treatment is not less than 0.1mm, the total thickness of the oxidation layer is not more than 1mm, and the depth of a decarburized layer is not more than 1.5 mm.

The piercing-rolling integrated four-section type composite plug comprises the following alloy chemical components: 0.16-0.28% of carbon, 0.2-1.95% of silicon, 0.16-0.63% of manganese, 2.6-3.31% of nickel, 0.6-1.86% of chromium and 0.03-0.04% of total phosphorus and sulfur.

The invention has the beneficial effects that:

the piercing plug structure is designed in a four-section mode, is more suitable for metal thermoplastic deformation, improves the quality of the inner surface of a perforated tubular billet, and avoids the problems of loose center of a rolled tube, rolling and folding of the surface of a tube body and the like.

And secondly, the top is a composite top, the base material of the top can be repeatedly utilized, the consumption of punching application is reduced, the consumption of rolling hot tools in the punching process is reduced, the quality of the capillary tube rolled by nonferrous metals is improved, and the processes of penetrating, rolling, fixing and penetrating and rolling integration and the like can be realized to complete the product rolling of the nonferrous metal seamless tube.

Drawings

Fig. 1 is a schematic structural diagram of a first embodiment of the present invention.

Fig. 2 is a schematic structural diagram of a second embodiment of the present invention.

In the figure: 1 is I section, 2 is II section, 3 is III section, 4 is IV section, 5 is the nose, 6 is the connection tail handle, 7 is the screw thread hole.

Detailed Description

The invention is further explained below with reference to the drawings.

A piercing-rolling integrated four-section type composite plug comprises a nose part 5, a cone body and a straight section 4, wherein the cone body comprises a section I1, a section II 2 and a section III 3 which are connected smoothly in sequence, the β angle of the section I1 is 3-4 degrees, the β angle of the section II 2 is 5.3-7.2 degrees, the β angle of the section III 3 is 4.38-5.2 degrees, the outer edge of the straight section 4 is a cylindrical surface, and the length ratio of the section I1, the section II 2, the section III 3 to the straight section 4 is 1.4: 3.0: 2.4: 1.0-1.04.

The penetrating and rolling integrated four-section type composite plug is characterized in that the β angle of the section I1 is 3-4 degrees, the β angle of the section II 2 is 5.3-7.2 degrees, and the β angle of the section III 3 is 4.3-5.2 degrees.

The matrix hardness of the plug is not lower than 230 HBW; the plug is processed by an oxidation heat treatment process, the thickness of an inner layer oxidation layer of the plug after the oxidation heat treatment is not less than 0.1mm, the total thickness of the oxidation layer is not more than 1mm, and the depth of a decarburized layer is not more than 1.5 mm.

The alloy of the plug comprises the following chemical components: 0.16-0.28% of carbon, 0.2-1.95% of silicon, 0.16-0.63% of manganese, 2.6-3.31% of nickel, 0.6-1.86% of chromium and 0.03-0.04% of total phosphorus and sulfur.

The manufacturing process of the plug comprises the steps of manufacturing a matrix, remelting laser and plasma spraying, machining the geometric dimension of the shape and heat treatment. The diameter of the plug is phi 48 mm-409 mm, the length is 85-970 mm, and the manufacturing process meets the relevant national standards or ISO and DIN standards. The tail part of the ejector head can be a connection tail handle 6 or a threaded connection hole 7 structure, the connection tail handle 6 is connected with the ejector rod in a pin connection mode, and the threaded connection hole 7 is connected with the ejector rod in a binding mode. The joint is suitable for the piercing rolling of seamless pipes made of various non-ferrous metals such as zirconium, niobium and titanium, Tc4 and Ti80, and has the product specification phi of 60-phi 477 multiplied by 4-38 mm and the finished product pipe of 6-12.5 m.

In the machining engineering, the dimensional tolerance, the shape and position tolerance and the surface roughness meet the drawing requirement standard. The limit deviation of tolerance dimension not noted in the drawing is in accordance with GB/T1804-2000V grade; the support surface at the tail part of the plug performs GB/T1184-1996H grade on the verticality of the diameter of the support surface, and the outer surface of the plug performs GB/T1184-1996K grade on the circular runout of the axis; the surface roughness is not noted to meet the requirement of GB/T1031 on the machined surface, and no groove mark, bruise and the like are allowed.

The design scheme of the curved surface of the plug mainly obtains a strain velocity field, a stress field, deformation and force energy parameters in the rolling process according to the basic relation of plastic mechanics and an constitutive equation. And analyzing corresponding parameters of the plug in the metal plastic forming process in the rolling process by using a finite element method. The rigid-plastic finite element method is used for solving by adopting a rigid-plastic material constitutive model. The design of the plug is based on the variation principle of rigid plastic materials, an energy consumption rate functional is expressed as a nonlinear function of node speed according to a finite element mode, an optimal solution meeting an extreme value condition is obtained by utilizing a mathematical optimization theory, namely, a motion allowable speed field with the total energy consumption rate being the minimum value is obtained, then the curved surface of the plug is optimally designed, a cavity deformation process and rolling parameters in the optimal skew rolling process are simulated and designed, and further the plastic deformation of materials such as non-ferrous metals zirconium, niobium, titanium, Tc4 and Ti80 is realized to produce the non-ferrous metal seamless pipe with high quality.

The specific method comprises the following steps: the piercing-rolling integrated four-section type composite top head is arranged in a skew rolling deformation cavity according to technological tool parameters, a workpiece is divided into units connected with limited nodes, the speed (displacement) on the nodes is used as an unknown quantity, a corresponding equation set is solved by utilizing a minimum energy principle to determine the unknown quantity, the stress and the strain distribution of each unit are determined according to the relation between the node speed and the internal strain of the unit and the internal stress of the unit, and the design of the working curved surface of the piercing-rolling integrated four-section type composite top head is designed according to corresponding parameters, so that high-quality products are produced.

The four-section type composite plug is divided into four sections in the design of the outer curved surface so as to meet the quality requirement of rolling application, and is more suitable for the flow characteristic of nonferrous metals in the process of skew rolling plastic deformation. In order to achieve the aims of cost reduction, efficiency improvement, energy conservation, consumption reduction and high-efficiency production, the piercing-rolling integrated four-section type composite plug has the characteristic of repeated use in heavy turning, and a base body structure of the plug can be divided into two layer parts: the bottom layer is a substrate strength part and mainly ensures that the substrate structure does not crack, deform and other factors in the recycling process of the plug, so that the recycling of the plug substrate material is realized; the surface layer in contact with the capillary is an abrasion consumption layer which is a part in contact with a rolled piece, the material of the layer can be abraded and consumed in the rolling process, when the layer reaches the rolling quantity and can not ensure the quality of the capillary, the top is off-line, and after the layer is turned again to the layer of the base material, laser remelting plasma spraying, shape geometric dimension processing and top surface heat treatment are sequentially carried out, so that the recycling effect of the top is realized.

The heat treatment method comprises the following steps: and (3) carrying out slow oxidation heat treatment on the plug in an electric induction heating and heat preservation furnace at the temperature of 400-1000 ℃ for 5-8 days to generate a compact oxide layer on the surface, so that the service life of the plug is prolonged in the rolling process, and the quality of the inner surface of the capillary is guaranteed.

Attention should be paid to: the surface of the plug treated by oxidation should form a compact oxide layer with good adhesion to the matrix structure, and the oxide layer should not be allowed to appear brownish red. The thickness of the inner layer oxide layer of the plug is not less than 0.1mm, the total thickness of the oxide layer is not more than 1mm, the depth of the decarburization layer is not more than 1.5mm, and the hardness of the matrix (except for the decarburization layer) is not less than 230 HBW.

The range of the chemical components of the plug alloy is as follows: c = 0.16-0.28%, Si = 0.2-1.95%, Mn = 0.16-0.63%, Ni = 2.6-3.31%, Cr = 0.6-1.86%; p, S = 0.03-0.04%; the allowable deviation of the chemical composition of the alloy is in accordance with the GB/T222 regulation. The chemical compositions of the steel respectively conform to GB/T699-1999, GB/T1299-2000 and GB/T3077-1999. The hardness of the plug is between HBW220 and 280.

The top head adopts a composite mode, the substrate layer is a structural layer, and the surface layer is a wear consumption bottom layer. The strength part of the matrix mainly ensures that the matrix structure does not crack, deform and other factors in the recycling process of the plug.

Claims

1. The piercing-rolling integrated four-section type composite plug is characterized by comprising a nose part (5), a cone body and a straight section (4), wherein the cone body comprises a section I (1), a section II (2) and a section III (3) which are connected smoothly in sequence, the β angle of the section I (1) is 3-4 degrees, the β angle of the section II (2) is 5.3-7.2 degrees, the β angle of the section III (3) is 4.38-5.2 degrees, the outer edge of the straight section (4) is a cylindrical surface, and the length ratio of the section I (1), the section II (2), the section III (3) and the straight section (4) is 1.4: 3.0: 2.4: 1.0-1.04.

2. The piercing-rolling integrated four-section composite plug as claimed in claim 1, wherein the β angle of the section I (1) is 3-4 °, the β angle of the section II (2) is 5.3-7.2 °, and the β angle of the section III (3) is 4.3-5.2 °.

3. The piercing-rolling integrated four-section composite plug according to claim 1, characterized in that: the matrix hardness of the plug is not lower than 230 HBW; the plug is processed by an oxidation heat treatment process, the thickness of an inner layer oxidation layer of the plug after the oxidation heat treatment is not less than 0.1mm, the total thickness of the oxidation layer is not more than 1mm, and the depth of a decarburized layer is not more than 1.5 mm.

4. The piercing-rolling integrated four-section composite plug according to claim 1, characterized in that: the alloy of the plug comprises the following chemical components: 0.16-0.28% of carbon, 0.2-1.95% of silicon, 0.16-0.63% of manganese, 2.6-3.31% of nickel, 0.6-1.86% of chromium and 0.03-0.04% of total phosphorus and sulfur.