CN1099331C - Electronic method and equipment for drawing wire of elastic alloy - Google Patents

Abstract

The invention relates to an electronic wire drawing method and device for an elastic alloy wire. Firstly, two electric contacts are set at both ends of a mold through which the alloy wire passes, and a current and a voltage are applied between the two electric contacts to complete the electronic drawing of the alloy wire. Wire drawing. The device of the present invention includes a mold and two pairs of upper and lower brushes. The metal wire to be processed passes through the first pair of upper and lower brushes, the mold and the second pair of upper and lower brushes in sequence. The invention improves the performance and quality of the elastic alloy wire, reduces or even completely cancels intermediate annealing, strengthens the production process, improves productivity, saves energy consumption, and improves the ecological environment.

Description

Electronic wire drawing method and device for elastic alloy

technical field

The invention relates to an electronic wire drawing method and device for an elastic alloy, belonging to the technical field of metal material processing.

Background technique

Elastic alloys refer to alloys with high or constant elastic properties. They have the following characteristics: high and constant elastic modulus, small elastic limit, stable elastic modulus temperature coefficient and frequency temperature coefficient, high elastic storage energy, small elastic aftereffect and elastic hysteresis, high stress relaxation Resistance, high mechanical quality factor or low internal friction, etc. They are generally stainless alloys, and sometimes require other physical properties (such as good electrical conductivity, low expansion, non-magnetic, etc.). They are mainly used in the manufacture of instruments and meters, automation devices, precision machinery, and various components in precision measurement, communication, and computing technologies, such as hairsprings, tension wires, spring tubes, coil springs, reeds, diaphragm boxes, bellows, Tuning forks, mechanical filters, delay lines, delay reservoirs, etc. are a class of important precision functional alloys with high requirements.

The performance and quality of this type of alloy are not only affected by the composition of the alloy, but also the production process has a decisive impact on its performance and quality. Taking the most important constant elastic alloy Ni42CrTiAl (my country's brand is 3J53) as an example, its production process is: vacuum melting → forging → hot rolling → annealing + pickling or alkali cleaning → cold drawing (wire) or cold rolling (strip) → Finished heat treatment and inspection. Among them, the intermediate deformation of cold working is about 70%. The reduction of the finished cold-rolled strip is about 50-60%, and the deformation of the finished cold-drawn wire is generally 55-70%, and a certain plastic reserve is reserved. The intermediate annealing is 950～1050℃, 10～30min water cooling. The heat treatment of the finished product is 950-1000°C, 20-30min solid solution, and then 550-650°C, 2-3h aging treatment.

The production shows that the disadvantages of the above-mentioned alloys are: ①The performance is too sensitive to the change of composition and heat treatment process parameters, so it is unstable; ②Due to the high strength, the γ solid solution matrix is easy to precipitate intermetallic during deformation due to the high degree of alloying compound, the plasticity is not very good, especially the cold forming process performance is not good when the deformation is large, so the wire drawing must be frequently annealed in the middle, and the production efficiency is very low; The inhomogeneity of the diameter and the like causes the directionality, inconsistency and nonlinearity of the material elasticity; ④ The inhomogeneity of the structure and the like also increases the internal friction of the alloy and reduces the mechanical quality factor of the elastic alloy; ⑤ The surface condition of the repeatedly drawn wire product is not good , is not smooth, has scratches and microcracks, greatly reducing the performance and service life of precision components, which has become a major problem in actual production and sales.

Contents of the invention

The purpose of the present invention is to propose an electronic wire drawing method and device for elastic alloys, replace the traditional cold drawing process with advanced electronic wire drawing process, fundamentally innovate the cold drawing processing technology, improve the performance and quality of elastic alloy wire, reduce or even Completely cancel intermediate annealing, strengthen the production process, increase productivity, save energy consumption, and improve the ecological environment.

The electronic wire drawing method of the elastic alloy wire proposed by the present invention comprises the following steps:

(1) Two electric contacts are set at the two ends of the mold through which the alloy wire passes, and the ratio of the distance between the two electric contacts and the two ends of the die is M: N=6:4;

(2) Apply current and voltage between two electrical contacts, where the critical current density of the pulse peak is j=10 ³ A/mm ² , J=I _max /F, where I _max is the peak current and F is the alloy wire cross-sectional area. The working voltage is V=200~700V, the current pulse width is tp=10 ^-5 ~10 ^-4 s, and the circuit pulse frequency is f=50~2000Hz. The above-mentioned alloy wire is completely electronically drawn.

According to the method of the present invention, an electronic wire drawing device for elastic alloy wire is specially designed, and the device includes a mold and two pairs of upper and lower brushes. Two pairs of upper and lower brushes are respectively placed on the two sides of the mould, and the metal wire to be processed passes through the first pair of upper and lower brushes, the mold and the second pair of upper and lower brushes in sequence. The ratio of the distance M of the mold to the distance N of the second pair of brushes from the mold is: M:N=6:4; the upper brush in each pair of brushes is close to the mold, the lower brush is outside the upper brush, and Interpenetrate each other. The lower electric brush is placed in the sleeve of the support, and the lower end of the sleeve has a sleeve cap, and a spring is built in the sleeve cap, and the spring is connected with the lower electric brush.

Compared with the traditional wire drawing technology, the method and device of the present invention have the following advantages or characteristics:

1. Significantly reduce the wire drawing force and significantly improve the plastic deformation ability of the alloy, thus greatly improving the wire drawing process performance of the material and saving energy consumption.

2. Reduce or even completely cancel the intermediate annealing of wire drawing, which greatly simplifies and strengthens the production process, improves production efficiency and increases economic benefits.

3. Improve the comprehensive mechanical properties of the wire, improve the uniformity and stability of the surface quality and performance, which is very beneficial to precision alloys, especially alloys that require stable performance such as constant elasticity.

4. Due to the reduction or cancellation of annealing and related cleaning and cleaning procedures, the production ecological environment is fundamentally improved.

5. It makes it possible to draw and form hard-to-deform and low-plastic materials (such as high-strength, high-elasticity alloys, high-melting point metals, intermetallic compounds, powder metallurgy materials, conductive ceramics, etc.).

Description of drawings:

Fig. 1 is a schematic structural view of an electronic wire drawing device designed in the present invention.

In Figure 1, 1 is a sleeve, 2 is a bracket, 3 is a lower brush, 4 is a sleeve, 5 is a drawn wire, 6 is a support, 7 is a sleeve cap, 8 is a spring, and 9 is a wire. The 10th is a mold support, the 11th is a mould, and the 12th is an upper electric brush.

Detailed ways

As shown in Figure 1, the electronic wire-drawing device designed by the present invention includes a mold 11 and two pairs of upper and lower brushes 3,12. Two pairs of upper and lower brushes are respectively placed on the two sides of the mold 11, and the metal wire 5 to be processed passes through the first pair of upper and lower brushes, the mold and the second pair of upper and lower brushes successively. The ratio of the distance M between the brush and the mold and the distance N between the second pair of brushes and the mold is: M:N=6:4; the upper brush 12 in each pair of brushes is close to the mold, and the lower brush 3 is in the position of the upper brush 12, and overlap each other. The lower brush is placed in the sleeve 4 of the support 6, the lower end of the sleeve has a sleeve cap 7, and a spring 8 is built in the sleeve cap, and the spring is connected with the lower brush 3.

It can be seen from the figure that according to the method, a pulse current with high density and short pulse width is introduced into the deformation zone of the alloy wire from both ends of the wire drawing die, so that the wire drawing process is carried out under the action of electrons. The key lead joint adopts the brush contact structure, relying on the springs in the upper and lower sleeves to keep the alloys in the flat grooves on the top of the two pairs of upper and lower brushes in stable and good electrical contact. in:

(1) The distance between the joint and the wire drawing die should be as close as possible under the conditions of the operating space.

(2) The distance between the front and rear joints and the wire drawing die should maintain a ratio of 6:4.

(3) The groove surface of the two upper brushes and the hole surface of the wire drawing die should be on the same level.

The principle of the present invention is: according to the metal physics point of view, the stress deformation of metal (for example, wire drawing) is a process in which stress drives dislocation movement. In the process of dislocation movement, if a high-density current is applied, a high-concentration electron wind will be generated in the metal, and the wind pressure formed by the electron wind will help to push the moving dislocation in the direction of deformation and overcome Obstacles, reducing the proliferation of dislocations, reducing the deformation resistance of metals, slowing down and reducing work hardening, so the plasticity of metals is greatly improved. This is the electronic plastic effect in metals, which is the theoretical basis of the present invention. Although the electroplastic effect has been discovered for more than 30 years, there is no public report on its application in the wire drawing process, especially in elastic alloys.

The DC pulse power supply device is designed and manufactured by using the principle of solid capacitor charge and discharge. ①The amplitude current provided can ensure the critical current density (about 10 ⁵ A/cm ² ) required for the electronic plastic effect during wire drawing processing; ②It can adapt to the wire drawing speed (0.1～10m/s), the frequency of the current pulse can be as high as 10 ⁴ Hz; ③To prevent fusing or heating of the wire, the pulse width should not exceed 10 ² μs; ④To ensure the output of high current density, the voltage should be above 500V and adjustable. This is a new type of power supply that is different from conventional ones. It is characterized by high current and frequency at the same time (this is also the difficulty of manufacturing); in order to ensure the absolute safety of operators, the design should adopt artificial floating ground.

The electronic wire drawing operation is carried out by directly feeding electricity to the deformation zone (ie, the two ends of the mold). The key in the device is the electrical connector, which must ensure stable and reliable electrical contact during work, and any poor contact will lead to ignition and burning. A sealed elastic contact system proposed in the present invention solves the reliability problem of electric conduction.

The effective implementation of the electronic wire drawing process mainly lies in the optimal combination of electrical parameters (including output voltage, amplitude current, pulse frequency, pulse width, duty cycle, etc.) and deformation parameters (deformation scheme, deformation amount, deformation speed, etc.), and at the same time Consider material properties and lubricant conditions. The implementation steps are generally: ①According to the final size requirements of the alloy wire, formulate the use plan of the draw rate; ②Select the voltage according to the diameter of the wire to determine the current to ensure the basic requirements of the critical current density; ③According to the wire drawing speed and wire diameter Select a reasonable current frequency, and grasp its changing law; ④ adjust the duty cycle and current pulse width, and maintain the stability of the current and wire temperature during operation; ⑤ determine the adjustability of the last pass according to the final performance requirements of the wire Wire drawing system.

Embodiments of the present invention are described below.

Embodiment 1: 3J53 alloy electronic wire drawing The electronic wire drawing process parameters that can be used for drawing 3J53 alloy wire from φ2.3mm to φ0.66mm are:

(1) Current density: j=Imax/F=370～1500A/mm ²

(2) Working voltage: 250V

(3) Current pulse width tp=80～100μs

(4) Current pulse frequency f＝50～500Hz

The lowest drawing speed of the alloy is 0.1m/s. Shrinkage rate (deformation rate) ε=1-(d/d ₀ ) ² =90%. Compared with traditional wire drawing, the deformation of electronic wire drawing increases, and the drawing force decreases by 30-40%. The intermediate annealing is canceled, and the surface quality is significantly improved (no cracks, high finish).

Embodiment 2: 317L steel wire electronic wire drawing

317L steel wire drawn from φ1.60mm to φ0.12 can adopt the electronic wire drawing process parameters as follows:

(1) Current density: j=Imax/F=500～2000A/mm ²

(2) Working voltage: 250V

(3) Current pulse width: tp=80～100μs

(4) Current pulse frequency: f＝50～900Hz

The drawing speed of steel wire is 0.1m/s. Shrinkage rate (deformation degree) ε=1-(d/d ₀ ) ² =99.4%. Compared with traditional wire drawing, the deformation of electronic wire drawing is greatly increased, and the wire drawing force is reduced by 30-40%. The strength of the wire is reduced by 10%, the intermediate annealing (2-3 times) is completely canceled, and the surface quality is greatly improved.

Example 3: Cr17Ni6Mn3 steel wire electronic wire drawing

Cr17Ni6Mn3 steel wire drawn from φ2.00mm to φ0.226 can adopt electronic wire drawing process parameters as follows:

(1) Current density: j=Imax/F=350～1500A/mm ²

(2) Working voltage: 250V

(3) Current pulse width tp=80～100μs

(4) Current pulse frequency f＝50～600Hz

The drawing speed of steel is 0.1-1m/s. Shrinkage rate (degree of deformation) ε=1-(d/d ₀ ) ² =98.2%. Compared with traditional wire drawing, the deformation of electronic wire drawing increases, and the drawing force decreases by 20-40%. The internal stress in the wire is reduced by 5-6%, the strength is reduced by ~10%, and the surface quality is obviously improved.

Claims (2)

1. An electronic wire drawing method for elastic alloy wire, characterized in that the method comprises the following steps: (1) Two electric contacts are set at the two ends of the mold through which the alloy wire passes, and the ratio of the distance between the two electric contacts and the two ends of the die is M: N=6:4; (2) Apply current and voltage between two electrical contacts, wherein the critical current density of the pulse peak is j=500-2000A/mm ² , the operating voltage is V=250V, and the current pulse width is tp=80-100μs, the circuit The pulse frequency is f=50-900Hz, and the alloy wire treated above has completed electronic wire drawing. 2. An electronic wire drawing device for elastic alloy wire, characterized in that the device includes a mold and two pairs of upper and lower brushes, and the two pairs of upper and lower brushes are respectively placed on two sides of the mold, and the metal to be processed The wire passes through the first pair of upper and lower brushes, the mold and the second pair of upper and lower brushes in turn. The ratio of the distance M between the first pair of brushes and the mold and the distance N between the second pair of brushes and the mold is : M: N = 6: 4; the upper brush in each pair of brushes is close to the mould, the lower brush is on the outside of the upper brush, and overlaps each other, and the lower brush is placed in the sleeve of the support , There is a sleeve cap at the lower end of the sleeve, and a spring is built in the sleeve cap, and the spring is connected with the brush.