CN101537435B

CN101537435B - Dieless drawing forming process for conical metal pipe

Info

Publication number: CN101537435B
Application number: CN2009100836154A
Authority: CN
Inventors: 谢建新; 毛浩恩; 刘雪峰
Original assignee: University of Science and Technology Beijing USTB
Current assignee: University of Science and Technology Beijing USTB
Priority date: 2009-05-06
Filing date: 2009-05-06
Publication date: 2011-04-20
Anticipated expiration: 2029-05-06
Also published as: CN101537435A

Abstract

The invention belongs to the field of metal thermal processing, relates to a forming method of metal pipe fittings with variable cross-sections, and in particular provides a dieless drawing forming process for metal tapered pipes, which can be used for stainless steel, carbon steel, alloy steel, aluminum alloy, copper alloy , Titanium alloy and other conical tube forming. The forming of metal tapered tubes is realized by controlling the blank drawing speed, feeding speed (or moving speed of cold and heat sources), induction heating temperature, distance between cold and heat sources and other process parameters, which solves the complex process of producing tapered tubes in conventional methods , many processes, large material loss and other shortcomings. The invention has the following advantages: using equal-diameter welded pipe billet or seamless pipe billet as raw material, the tapered pipe is formed by direct dieless drawing through heating and cooling, the process flow is short, and the production cost is low; the processing process does not produce waste, and the material utilization rate is high High; large degree of freedom in product shape and specification, high product size accuracy, large single-pass section reduction rate, and high production efficiency.

Description

A Dieless Drawing Forming Process for Conical Metal Tubes

技术领域technical field

本发明属于金属热加工领域，涉及一种变截面金属管件的成形方法，特别提供了一种金属锥形管无模拉拔成形工艺，可用于不锈钢、碳钢、合金钢、铝合金、铜合金、钛合金等锥形管的成形。The invention belongs to the field of metal thermal processing, relates to a forming method of metal pipe fittings with variable cross-sections, and in particular provides a dieless drawing forming process for metal tapered pipes, which can be used for stainless steel, carbon steel, alloy steel, aluminum alloy, copper alloy , Titanium alloy and other conical tube forming.

背景技术Background technique

随着经济和社会的发展，机械制造、石油、化工、能源、海洋、城市建设等领域对金属锥形管的需求量越来越大，采用锥形管可以实现结构优化设计，达到节省材料和减轻构件重量等目的。With the development of economy and society, the demand for metal tapered pipes in the fields of machinery manufacturing, petroleum, chemical industry, energy, ocean, and urban construction is increasing. The use of tapered pipes can achieve structural optimization design, saving materials and To reduce the weight of components, etc.

目前金属锥形管的加工方法主要有焊接、变截面有模拉拔、变截面挤压、推拔法等。焊接法是根据成品锥形管的强度和尺寸要求，选择不同厚度的板材，并将板材加工成梯形，然后卷曲，焊接成形。该工艺成形的锥形管存在焊缝，整体美观性较差，具有工艺复杂、材料浪费大、设备投资大、成本高等缺点；此外，由于焊接区域需要有一定的厚度，且板材卷曲时半径不能太小，因而难以生产壁薄或直径小的锥形管。变截面有模拉拔、变截面挤压、推拔法都是采用模具成形的方法[王素芬.推拔式无缝锥形管[P].中国实用新型专利，授权号ZL200620168317.7，授权日：2008-02-06]，对大直径薄壁管材的加工很困难，并且使用模具，生产成本较高；另外，受模具的限制，在生产细长件时也有局限性。At present, the processing methods of metal tapered pipe mainly include welding, variable cross-section die drawing, variable cross-section extrusion, push-pull method, etc. The welding method is to select plates of different thicknesses according to the strength and size requirements of the finished tapered pipe, and process the plates into trapezoidal shapes, then crimp them, and weld them into shape. The tapered pipe formed by this process has weld seams, poor overall aesthetics, complex process, large material waste, large equipment investment, and high cost; in addition, because the welding area needs to have a certain thickness, and the radius of the plate cannot Too small, making it difficult to produce tapered tubes with thin walls or small diameters. Die-drawing with variable cross-section, extrusion with variable cross-section, and push-pull method are all methods of mold forming [Wang Sufen. Push-pull seamless tapered pipe [P]. Chinese utility model patent, authorization number ZL200620168317.7, date of authorization : 2008-02-06], it is very difficult to process large-diameter thin-walled pipes, and molds are used, and the production cost is relatively high; in addition, limited by molds, there are also limitations in the production of slender parts.

无模拉拔是一种不采用模具而进行金属成形的柔性近终成形技术，克服了其他加工方法流程长、成本高、单道次变形量小等缺点，具有设备规模小、生产灵活性高，易于实现自动控制等优点[黄贞益，王萍，孔维斌，等.无模拉伸工艺及发展[J].华东冶金学院学报，2000，17(2)：118～120]。Dieless drawing is a flexible near-net forming technology for metal forming without using a mold. It overcomes the shortcomings of other processing methods such as long process, high cost, and small deformation in a single pass. It has small equipment scale and production flexibility. High, easy to achieve automatic control and other advantages [Huang Zhenyi, Wang Ping, Kong Weibin, etc. No die drawing process and development [J]. Journal of East China Institute of Metallurgy, 2000, 17 (2): 118 ~ 120].

无模拉拔分为非连续式和连续式两种(见图1～3)。非连续式无模拉拔的特点是：坯料一端固定，另一端以一定的速度拉拔，同时冷热源从坯料的一端移动到另一端，通过控制拉拔速度(v_t)和冷热源移动速度(v_i)实现成形，适合于成形大断面、长度较短的产品；连续式无模拉拔的特点是：坯料从一端连续送进，另一端以一定的速度拉拔，在拉拔速度(v_t)大于进料速度(v_i)的条件下实现连续成形，适合于生产长尺寸产品。Dieless drawing is divided into two types: discontinuous and continuous (see Figures 1-3). The characteristics of discontinuous dieless drawing are: one end of the billet is fixed, the other end is drawn at a certain speed, and the cold and heat source moves from one end of the billet to the other end at the same time, by controlling the drawing speed (v _t ) and the cold and heat source The moving speed (v _i ) realizes forming, which is suitable for forming products with large cross-section and short length; the characteristics of continuous dieless drawing are: the blank is continuously fed from one end, and the other end is drawn at a certain speed. Continuous forming is realized under the condition that the speed (v _t ) is greater than the feed speed (v _i ), which is suitable for the production of long-sized products.

发明内容Contents of the invention

本发明的目的在于提供一种金属锥形管无模拉拔成形工艺。通过控制坯料拉拔速度、进料速度(或冷热源移动速度)以及感应加热温度、冷热源距离等工艺参数来实现金属锥形管的成形，解决了常规方法生产锥形管存在工艺复杂、工序多、材料损耗大等缺点。The object of the present invention is to provide a metal tapered tube dieless drawing forming process. The forming of metal tapered tubes is realized by controlling the blank drawing speed, feeding speed (or moving speed of cold and heat sources), induction heating temperature, distance between cold and heat sources and other process parameters, which solves the complex process of producing tapered tubes in conventional methods , many processes, large material loss and other shortcomings.

一种基于连续无模拉拔的金属锥形管成形工艺，其特征在于：A metal tapered tube forming process based on continuous dieless drawing, characterized in that:

(1)原材料选择：直径D₀＝(1～1.1)D₁、壁厚t₀＝(1～1.1)t₁的无缝或有缝不锈钢、碳钢、合金钢、铝合金、铜合金、钛合金等金属的等径管坯，D₁、t₁分别为产品大端直径和壁厚。(1) Selection _of _raw materials: seamless or seamed stainless steel, carbon steel, alloy steel, _aluminum _alloy , copper alloy, Isometric tube blanks of titanium alloy and other metals, D ₁ and t ₁ are the diameter and wall thickness of the large end of the product respectively.

(2)等径管坯在感应线圈加热和冷却装置冷却的共同作用下形成一段软化区，感应加热温度为T＝(0.5～0.95)T_m，T_m为材料的熔点(单位：K)；冷却水流量为10～200L/h；感应线圈和冷却水装置之间的距离为0＜S₀≤5D₀。(2) The equal-diameter tube blank forms a section of softening zone under the joint action of induction coil heating and cooling device cooling, the induction heating temperature is T=(0.5～0.95)T _m , and T _m is the melting point of the material (unit: K); The cooling water flow rate is 10-200L/h; the distance between the induction coil and the cooling water device is 0<S ₀ ≤5D ₀ .

(3)管坯一端送进，一端拉拔，进料速度v_i等于初始拉拔速度v₀，拉拔速度v_t按拉拔速度模型呈非线性逐渐增大；随着拉拔速度的增大，管材直径连续减小，形成外锥度α的金属锥形管(见图4)，0＜α≤1°。(3) One end of the tube blank is fed and the other end is drawn, the feeding speed v _i is equal to the initial drawing speed v ₀ , and the drawing speed v _t increases nonlinearly according to the drawing speed model; with the increase of the drawing speed Large, the diameter of the pipe decreases continuously, forming a metal tapered pipe with an outer taper α (see Figure 4), 0<α≤1°.

(4)拉拔过程中断面缩减率逐渐增大，单道次断面缩减率最大可达65％。(4) The reduction rate of the cross section increases gradually during the drawing process, and the maximum reduction rate of the cross section in a single pass can reach 65%.

(5)无模拉拔成形金属锥形管的壁厚逐渐减薄，其内锥度β为 $\tan β = k (1 - 2 \frac{t_{0}}{D_{0}}) \tan α,$ 其中k＝1.0～1.2。(5) The wall thickness of the metal conical tube formed by dieless drawing is gradually reduced, and its inner taper β is $the tan β = k (1 - 2 \frac{t_{0}}{{D.}_{0}}) the tan α,$ Wherein k=1.0～1.2.

(6)所述无模拉拔速度v_t的模型为(6) The model of the dieless drawing speed v _t is

${v v}_{t t} = = ((\frac{{A A}_{11}}{{A A}_{22}} - - 11)) {v v}_{i i}$

式中，v_i-进料速度；In the formula, v _i - feed rate;

${A A}_{11} = = 22 {S S}_{00} + + 22 \frac{{D D.}_{00}^{22} - - {(({D D.}_{00} - - 22 {t t}_{00}))}^{22}}{[[{D D.}_{00} - - (({D D.}_{00} - - 22 {t t}_{00})) / / k k]] tan the tan α α};;$

${A A}_{22} = = \frac{{S S}_{00}}{22} + + \frac{{D D.}_{00}^{22} - - {(({D D.}_{00} - - 22 {t t}_{00}))}^{22}}{22 [[{D D.}_{00} - - (({D D.}_{00} - - 22 {t t}_{00})) / / k k]] tan the tan α α} + + \sqrt{{{\frac{{S S}_{00}}{22} + + \frac{{D D.}_{00}^{22} - - {(({D D.}_{00} - - 22 {t t}_{00}))}^{22}}{22 [[{D D.}_{00} - - (({D D.}_{00} - - 22 {t t}_{00})) / / k k]] tan the tan α α}}}^{22} - - 22 \frac{{D D.}_{00}^{22} - - {(({D D.}_{00} - - 22 {t t}_{00}))}^{22}}{[[{D D.}_{00} - - (({D D.}_{00} - - 22 {t t}_{00})) / / k k]] tan the tan α α} {v v}_{i i} t t};;$

t-时间。t - time.

本发明提供的金属锥形管成形工艺具有以下优点：采用等径焊管坯或无缝管坯为原料，通过加热和冷却直接无模拉拔成形锥形管，工艺流程短，生产成本低；加工过程不产生废料，材料利用率高；产品形状规格自由度大、产品尺寸精度高，单道次断面缩减率大，生产效率高。适于各种金属锥形管的加工，如不锈钢、碳钢、合金钢、钛合金、铝合金、铜合金等。The metal tapered pipe forming process provided by the invention has the following advantages: using equal-diameter welded pipe blanks or seamless pipe blanks as raw materials, directly drawing and forming tapered pipes without dies through heating and cooling, the process flow is short, and the production cost is low; processing The process does not generate waste, and the material utilization rate is high; the product shape and specification have a large degree of freedom, the product size accuracy is high, the single-pass section reduction rate is large, and the production efficiency is high. Suitable for processing various metal conical tubes, such as stainless steel, carbon steel, alloy steel, titanium alloy, aluminum alloy, copper alloy, etc.

附图说明Description of drawings

图1为连续式无模拉拔原理示意图。其中1加热装置、2冷却装置。Figure 1 is a schematic diagram of the principle of continuous dieless drawing. Among them, 1 heating device and 2 cooling devices.

图2为v_i与v_t反向的非连续式无模拉拔原理示意图。Fig. 2 is a schematic diagram of the discontinuous modeless drawing principle in which v _i and v _t are reversed.

图3为v_i与v_t同向的非连续式无模拉拔原理示意图。Fig. 3 is a schematic diagram of the discontinuous dieless drawing principle in which v _i and v _t are in the same direction.

图4为无模拉拔产品形状示意图。Figure 4 is a schematic diagram of the shape of a moldless drawn product.

具体实施方式Detailed ways

实施例1：大端尺寸为φ6×1mm、锥度0.4°的304不锈钢锥形管的成形。Example 1: Forming of a 304 stainless steel conical tube with a large end size of φ6×1 mm and a taper of 0.4°.

(1)坯料为D₀＝6mm、t₀＝1mm的304不锈钢管坯；(1) The blank is a 304 stainless steel tube blank with D ₀ =6mm and t ₀ =1mm;

(2)冷却和加热工艺参数：感应加热温度为T＝0.95T_m，感应线圈和冷却水装置之间的距离为S₀＝5D₀，冷却水流量为50L/h；(2) Cooling and heating process parameters: the induction heating temperature is T=0.95T _m , the distance between the induction coil and the cooling water device is S ₀ =5D ₀ , and the cooling water flow rate is 50L/h;

(3)管坯进料速度为35mm/min；拉拔速度控制模型为 $v_{t} = (\frac{24.0}{6.0 + \sqrt{36.0 - 0.1 t}} - 1) \times 35,$ 其中初始拉拔速度为35mm/min；(3) The feeding speed of the tube billet is 35mm/min; the drawing speed control model is $v_{t} = (\frac{24.0}{6.0 + \sqrt{36.0 - 0.1 t}} - 1) \times 35,$ Wherein the initial drawing speed is 35mm/min;

(4)在上述条件下进行无模拉拔，管坯直径连续减小，形成外锥度α＝0.38°锥形管；(4) Under the above conditions, dieless drawing is carried out, and the diameter of the tube blank is continuously reduced to form a tapered tube with an external taper α=0.38°;

(5)拉拔后产品壁厚由1mm逐渐减薄，最薄0.7mm， $\tan β = 1.12 (1 - 2 \frac{t_{0}}{D_{0}}) \tan α,$ 最大断面缩减率60％。(5) After drawing, the wall thickness of the product is gradually reduced from 1mm to the thinnest 0.7mm. $the tan β = 1.12 (1 - 2 \frac{t_{0}}{{D.}_{0}}) the tan α,$ The maximum section reduction rate is 60%.

实施例2：大端尺寸为φ6×1.5mm、锥度0.5°的Ti-50.5mol％Ni合金锥形管的成形。Example 2: Forming of a Ti-50.5mol% Ni alloy conical tube with a large end size of φ6×1.5mm and a taper of 0.5°.

(1)坯料为D₀＝6mm、t₀＝1.5mm的Ti-50.5mol％Ni合金管坯；(1) The blank is a Ti-50.5mol% Ni alloy tube blank with D ₀ =6mm and t ₀ =1.5mm;

(2)冷却和加热工艺参数：感应加热温度为T＝0.5T_m，感应线圈和冷却水装置之间的距离为S₀＝0.8D₀，冷却水流量为10L/h；(2) Cooling and heating process parameters: the induction heating temperature is T=0.5T _m , the distance between the induction coil and the cooling water device is S ₀ =0.8D ₀ , and the cooling water flow rate is 10L/h;

(3)管坯进料速度45mm/min；拉拔速度控制模型为 $v_{t} = (\frac{17.7}{4.4 + \sqrt{19.7 - 0.1 t}} - 1) \times 45,$ 其中初始拉拔速度为45mm/min；(3) The feeding speed of the tube billet is 45mm/min; the drawing speed control model is $v_{t} = (\frac{17.7}{4.4 + \sqrt{19.7 - 0.1 t}} - 1) \times 45,$ Wherein the initial drawing speed is 45mm/min;

(4)在上述条件下进行无模拉拔，管坯直径连续减小，形成外锥度α＝0.47°锥形管；(4) Under the above conditions, dieless drawing is carried out, and the diameter of the tube blank is continuously reduced to form a tapered tube with an outer taper α=0.47°;

(5)拉拔后产品壁厚由1.5mm逐渐减薄，最薄1.0mm， $\tan β = 1.2 (1 - 2 \frac{t_{0}}{D_{0}}) \tan α,$ 最大断面缩减率55％。(5) After drawing, the wall thickness of the product is gradually reduced from 1.5mm, and the thinnest is 1.0mm. $the tan β = 1.2 (1 - 2 \frac{t_{0}}{{D.}_{0}}) the tan α,$ The maximum section reduction rate is 55%.

实施例3：大端尺寸为φ10×2mm、锥度0.6°的Cu-12wt％Al合金锥形管的成形。Example 3: Forming of a Cu-12wt% Al alloy conical tube with a large end size of φ10×2 mm and a taper of 0.6°.

(1)坯料为D₀＝10mm、t₀＝2mm的Cu-12wt％Al合金管坯；(1) The blank is a Cu-12wt%Al alloy tube blank with D ₀ =10mm and t ₀ =2mm;

(2)冷却和加热工艺参数：感应加热温度为T＝0.95T_m，感应线圈和冷却水装置之间的距离为S₀＝0.5D₀，冷却水流量为100L/h；(2) Cooling and heating process parameters: the induction heating temperature is T=0.95T _m , the distance between the induction coil and the cooling water device is S ₀ =0.5D ₀ , and the cooling water flow rate is 100L/h;

(3)管坯进料速度60mm/min；拉拔速度控制模型为 $v_{t} = (\frac{28.3}{7.0 + \sqrt{49.9 - 0.2 t}} - 1) \times 60,$ 其中初始拉拔速度为60mm/min；(3) The feeding speed of the tube billet is 60mm/min; the drawing speed control model is $v_{t} = (\frac{28.3}{7.0 + \sqrt{49.9 - 0.2 t}} - 1) \times 60,$ Wherein the initial drawing speed is 60mm/min;

(4)在上述条件下进行无模拉拔，管坯直径连续减小，形成外锥度α＝0.58°锥形管；(4) Under the above conditions, dieless drawing is carried out, and the diameter of the tube blank is continuously reduced to form a tapered tube with an external taper α=0.58°;

(5)拉拔后产品壁厚由2mm逐渐减薄，最薄1.18mm， $\tan β = 1.1 (1 - 2 \frac{t_{0}}{D_{0}}) \tan α,$ 最大断面缩减率61％。(5) After drawing, the wall thickness of the product is gradually reduced from 2mm to the thinnest 1.18mm. $the tan β = 1.1 (1 - 2 \frac{t_{0}}{{D.}_{0}}) the tan α,$ The maximum section reduction rate is 61%.

实施例4：大端尺寸为φ50×5mm、锥度0.5°的304不锈钢锥形管的成形。Embodiment 4: Forming of a 304 stainless steel conical tube with a large end size of φ50×5 mm and a taper of 0.5°.

(1)坯料为D₀＝50mm、t₀＝5mm的304不锈钢管坯；(1) The blank is a 304 stainless steel tube blank with D ₀ =50mm and t ₀ =5mm;

(2)冷却和加热工艺参数：感应加热温度为T＝0.7T_m，感应线圈和冷却水装置之间的距离为S₀＝5D₀，冷却水流量为200L/h；(2) Cooling and heating process parameters: the induction heating temperature is T=0.7T _m , the distance between the induction coil and the cooling water device is S ₀ =5D ₀ , and the cooling water flow rate is 200L/h;

(3)管坯进料速度30mm/min；拉拔速度控制模型为 $v_{t} = (\frac{16.4}{4.1 + \sqrt{16.8 - 0.008 t}} - 1) \times 30,$ 其中初始拉拔速度为30mm/min；(3) The feeding speed of the tube billet is 30mm/min; the drawing speed control model is $v_{t} = (\frac{16.4}{4.1 + \sqrt{16.8 - 0.008 t}} - 1) \times 30,$ Wherein the initial drawing speed is 30mm/min;

(4)在上述条件下进行无模拉拔，管坯直径连续减小，形成外锥度α＝0.48°锥形管；(4) Under the above conditions, dieless drawing is carried out, and the diameter of the tube blank is continuously reduced to form a tapered tube with an outer taper α=0.48°;

(5)拉拔后产品壁厚由5mm逐渐减薄，最薄3.0mm， $\tan β = 1.08 (1 - 2 \frac{t_{0}}{D_{0}}) \tan α,$ 最大断面缩减率53％。(5) After drawing, the wall thickness of the product is gradually reduced from 5mm to the thinnest 3.0mm. $the tan β = 1.08 (1 - 2 \frac{t_{0}}{{D.}_{0}}) the tan α,$ The maximum section reduction rate is 53%.

Claims

1. A metal tapered tube forming process based on continuous dieless drawing, characterized in that:

(1) Selection of raw materials: seamless or seamed alloy steel, carbon steel, aluminum alloy, copper alloy or titanium alloy with diameter D ₀ = (1～1.1)D ₁ and wall thickness t ₀ = (1～1.1)t ₁ D ₁ and t ₁ are the diameter and wall thickness of the large end of the product respectively, and the units of D ₀ , t ₀ , D ₁ and t ₁ are mm;

(2) Equal-diameter tube blanks form a section of softening zone under the joint action of induction coil heating and cooling device cooling, the induction heating temperature is T=(0.5～0.95)T _m , T _m is the melting point of the material, unit: K; cooling The water flow rate is 10~200L/h; the distance between the induction coil and the cooling device is 0<S ₀ ≤5D ₀ , S ₀ unit: mm;

(3) One end of the tube blank is fed and the other end is drawn. The feeding speed v _i is equal to the initial drawing speed v ₀ , the unit of v ₀ is mm/min, and the drawing speed v _t increases gradually nonlinearly according to the drawing speed model ;As the drawing speed increases, the diameter of the pipe decreases continuously, forming a metal tapered pipe with an outer taper α, 0<α≤1°;

(4) The section reduction rate in the drawing process gradually increases, and the single-pass section reduction rate reaches a maximum of 65%;

(5) The wall thickness of the metal conical tube formed by dieless drawing is gradually reduced, and its inner taper β is

Wherein k=1.0～1.2;

(6) The model of the drawing speed v _t is

{v v}_{t t} = = ((\frac{{A A}_{11}}{{A A}_{22}} - - 11)) {v v}_{i i}

In the formula, v _i -feed speed, unit: mm/min;

{A A}_{11} = = {22 S S}_{00} + + 22 \frac{{D D.}_{00}^{22} - - {(({D D.}_{00} - - {22 t t}_{00}))}^{22}}{[[{D D.}_{00} - - (({D D.}_{00} - - {22 t t}_{00})) / / k k]] tan the tan α α};;

{A A}_{22} = = \frac{{S S}_{00}}{22} + + \frac{{D D.}_{00}^{22} - - {(({D D.}_{00} - - {22 t t}_{00}))}^{22}}{22 [[{D D.}_{00} - - (({D D.}_{00} - - {22 t t}_{00})) / / k k]] tan the tan α α} + + \sqrt{{{\frac{{S S}_{00}}{22} + + \frac{{D D.}_{00}^{22} - - {(({D D.}_{00} - - {22 t t}_{00}))}^{22}}{22 [[{D D.}_{00} - - (({D D.}_{00} - - {22 t t}_{00})) / / k k]] tan the tan α α}}}^{22} - - 22 \frac{{D D.}_{00}^{22} - - {(({D D.}_{00} - - {22 t t}_{00}))}^{22}}{[[{D D.}_{00} - - (({D D.}_{00} - - {22 t t}_{00})) / / k k]] tan the tan α α} {v v}_{i i} t t};;

t-time, unit: min.