KR0182224B1 - Cu-zr-mischmetal alloy and the heat treatment thereof - Google Patents

Abstract

The present invention relates to the production of a copper (Cu) -zirconium (Zr) -mischmetal alloy, which is an electrode material for resistance welding and spot (spot) welding of an electrical contact member or a steel sheet, and a processing heat treatment capable of exhibiting the characteristics thereof. Copper (Cu) is the main component, and zirconium (Zr) is contained in the range of 0.25 to 3.00% (weight percentage), and here it is cerium copper Cu _X Ce, lanthanum copper Cu _X La, ni It is characterized in that it is added in the range of 0.02 to 0.50% (weight percentage) of the compound of the compound capable of producing precipitates, such as copper copper Cu _X Nd, and copper sintered copper Cu _X Pr As an alloying material, it relates to a processing heat treatment which can maintain hardness and electrical conductivity in the range of HRB 60 to 90 and IACS 70 to 95%, respectively.

The material thus produced has excellent hardness and conductivity at high temperatures, and exhibits excellent performance when used as an electrode for resistance welding or spot welding of electrical contacts or steel sheets, and the production method is as follows.

That is, ingot is prepared after melting the copper (Cu) alloy, and the forging, rolling, extrusion, etc. at 800 ~ 950 ℃ at a processing ratio of 7S (about 85%) or more that can remove the cast structure. Is maintained at 800 to 1,050 ° C for at least 30 minutes per inch of thickness, followed by quenching with water-cooling and oil-cooled copper to perform solution treatment, and cold processing such as rolling, forging, drawing, etc. at a processing rate of 70% or more at room temperature. After the above step is maintained at 350 to 550 ° C. for at least 1 hour, the age hardening heat treatment is performed by water cooling, oil cooling, or air cooling. According to the target properties of the material or product, the process order of cold working and age hardening heat treatment may be changed, and in some cases, the cold working process may be omitted.

Description

Copper-zirconium (zr) -mischmetal alloys and their heat treatment methods

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a copper-zirconium (Zr) -mischmetal alloy and a process heat treatment method of the alloy, and in particular, an electrode material for resistance welding and spot (spot) welding of electrical contact materials or steel sheets. Manufacture of Zirconium (Zr) -mischmetal alloys and their properties as an alloy with a conductivity of 75-85% pure copper and a hardness of 75-85 HRB, a Brinnel B-stain. It relates to a heat treatment method.

Copper (Cu) -chromium (Cr) binary alloy containing about 1% (by weight percent) of conventional chromium (Cr) is maintained at about 80% of pure copper by proper processing and heat treatment. It is possible to improve it by about 3 times, and industrially, it is used as resistance welding and spot welding electrode material of a contact material or a steel plate in the field of electrical and electronics.

According to the state diagram of the copper (Cu) -chromium (Cr) binary alloy, about 0.45 weight percent of copper (Cr) is dissolved in copper (Cr) when heated to about 1,000 ° C, which is the temperature near the solution treatment. In the aging treatment, fine chromium (Cr) particles are precipitated to strengthen the matrix, but when the aging temperature is higher than 450 ° C., the hardness decreases rapidly.

This phenomenon means that the material deteriorates rapidly when the material is subjected to thermal effects of 450 ° C. or higher during use.

In view of this, conventional copper (Cu) -chromium (Cr) binary alloys, when used as electrodes for resistance welding and spot (spot) welding of electrical contacts or steel sheets, have high current through high current under instantaneous high pressing force. Since the heat of resistance is generated, the consumption of the contact part is large, and there is a problem in that sticking phenomenon that often sticks to the contact object occurs.

These problems impair the life of the electrode and have the disadvantage of making the weld unclean.

On the other hand, in order to improve the characteristics of the copper (Cu) -chromium (Cr) binary alloy, when elements such as Al, Si, Be, Co, etc., which have high age hardenability, are added, the kind and amount of the elements The hardness can be improved to some extent with the increase of, but the conductivity is largely impaired.

An object of the present invention for solving the above problems is in addition to alloying zirconium (Zr), which is an element that can be dissolved and precipitated in copper (Cu) as the main component, instead of chromium (Cr), and the main component copper (Cu) and Ingot is added after dissolution by adding a compound such as cerium (Ce), lanthanum (La), nidium (Nd), praseodymium (Pr), and the like. In addition, it precipitates fine zirconium (Zr) particles during processing heat treatment, and precipitates fine and stable cerium copper, lanthanum copper, niobium copper, and praseodymium copper precipitates even at high temperatures. It is to provide an alloy and a heat treatment method of the alloy to improve the properties of the alloy.

The object of the present invention as described above is 0.25 to 3.00% (weight percent) zirconium (Zr) and 0.02% to 0.50% (weight percent) in the electrode material for resistance welding and spot (spot) welding of the electrical contact member or steel sheet Rate) Mischmetal and the remainder are made of copper (Cu), but the 0.02% to 0.50 (weight percentage) of the mischmetal is 50% (weight percentage) cerium (Ce), 25 (% By weight) lanthanum (La), 15% (weight percentage) Nidium (Nd), 5% (weight percentage) Praseodymium (Pr) It is achieved by providing a (Cu) -zirconium (Zr) -mischmetal alloy.

The object of the present invention as described above is 0.25 to 3.00% (weight percentage) zirconium (Zr) and 0.02% to 0.50% (in the heat treatment method for the resistance welding and spot (spot) welding electrode material of the electrical contact member or steel sheet) Weight percent) 7S (about 85%) or more capable of producing ingot after dissolving the mischmetal and the remainder of the copper (Cu) alloy made of copper (Cu), and removing the cast structure of the ingot Forging, rolling, extrusion, etc. are carried out at 800 to 950 ° C as a processing cost, and the solution is held at 800 to 1,050 ° C for 30 minutes or more, and then quenched by water cooling, oil cooling, etc. to perform solution treatment. In order to provide a large number of crossovers or densities of dislocations, which are nucleation sites of precipitates, in order to uniformly deposit a large amount of fine precipitates, cold processing such as rolling, forging, drawing, etc. is first performed at room temperature with a processing ratio of 70% or more. 1 hour at 350-550 ℃ Is achieved by providing a metal miswi (mischmetal) machining heat-treating process of the alloys of zirconium (Zr) - held after the water cooling, yunaeng, copper (Cu), characterized in that for performing the age hardening heat treatment by air cooling or the like.

When explaining the configuration and the operation of the embodiment of the present invention to achieve the object as described above and to perform the problem for removing the conventional defects in detail.

In the present invention, in addition to alloying zirconium (Zr), which is an element that can be dissolved and precipitated in copper (Cu) as a main component, instead of chromium (Cr), three elements, which are compounds that can form a compound with copper (Cu) as a main component Ingots were prepared after dissolution by adding a compound such as lithium (Ce), lanthanum (La), nidium (Nd), and praseodymium (Pr).

This results in the precipitation of fine zirconium (Zr) particles during processing heat treatment, and the formation of fine and stable cerium copper, lanthanum copper, niobium copper and praseodymium copper precipitates at high temperatures throughout the matrix to improve the properties of the material. It could be improved.

Mischmetal is composed of 50% by weight (ce) and 25% by weight of lanthanum (La), and 15% by weight of nidium (Nd). ) And a compound containing about 5% (percent by weight) of praseodymium (Pr).

In other words, the present invention is a method that can improve the properties of the material even at high temperatures, and the results of the examples show that the known hardness and conductivity are in the range of HRB 60-95 and IACS 70-90%, respectively, even at aging of 525 ° C or higher. As a way to maintain, this is described as follows.

Copper (Cu) as the main component, zirconium (Zr) is contained in the range of 0.25 to 3.00% (weight percentage), and zirconium (Zr) is zirconium (Zr) when containing solid solution strengthening, precipitation strengthening and supersaturation In order to exhibit the dispersion strengthening effect by the particles, the solid solution limit for the known copper (Cu) is 0.15% or more and the supersaturation range of 0.25 to 3.00% (weight percentage) is included. It produces fine precipitates such as Cu _X Ce, lanthanum copper Cu _X La, niobium copper Cu _X Nd, and prasadedium copper Cu _X Pr, maximizing precipitation strengthening effects and inhibiting grain growth during solution treatment. Mischmetal, a compound of elements, is added in a range of 0.02% to 0.50% (weight percent) to dissolve the alloy to prepare an ingot.

Ingots made of these components are made of materials and electrodes through the following three processing heat treatment steps, so that the fine and stable precipitates Cu _X Ce, Cu _X La, Cu _X Nd, Cu _X Pr, etc. are uniform in the matrix. It was distributed in large amounts to improve the durability of the electrode for resistance welding and spot welding of the electrical contact material or steel sheet.

end. First process plan

Zirconium (Zr) is contained 0.25 to 3.00% (weight percentage), and to the above, 0.02% to 0.50% (weight percentage) of mischmetal is added, and copper (Cu) remaining as copper (Cu) After melting the alloy, the ingot is manufactured, and the forging, rolling, extrusion, etc. are carried out at 800 to 950 ° C. with a processing ratio of 7 S (about 85%) or more to remove the cast structure of the ingot, and the thickness is 1 at 800 to 1,050 ° C. After holding for more than 30 minutes per inch, the solution is quenched by water cooling, oil cooling, etc., and the crossover and dense portions of dislocations, which are nucleation sites of precipitates, are deposited to uniformly deposit a large amount of fine precipitates during aging treatment. In order to prepare, first, cold processing such as rolling, forging, drawing, etc. is carried out at a processing temperature of 70% or more at room temperature, and after cold working, it is maintained at 350 to 550 ° C. for at least 1 hour and then subjected to age hardening heat treatment such as water cooling, oil cooling, or air cooling. The material that finished the process Use as is or to manufacture parts such as electrodes.

I. Second Process Plan

Zirconium (Zr) is contained 0.25 to 3.00% (weight percentage), and to the above, 0.02% to 0.50% (weight percentage) of mischmetal is added, and copper (Cu) remaining as copper (Cu) After melting the alloy, the ingot is manufactured, and the forging, rolling, extrusion, etc. are carried out at 800 to 950 ° C. with a processing ratio of 7 S (about 85%) or more to remove the cast structure of the ingot, and the thickness is 1 at 800 to 1,050 ° C. After holding at least 30 minutes per inch, the solution is quenched with water cooling, oil cooling, or the like, and solution solution treatment is performed. After the solution treatment, the solution is maintained at 350 to 550 ° C. for at least 1 hour, followed by age hardening heat treatment with water cooling, oil cooling, or air cooling. In order to uniformly disperse relatively coarse or partially developed precipitates and to obtain a work hardening effect, cold processing such as rolling, forging and drawing is performed at a processing cost of less than 70% at room temperature. Use it as it is Method for producing a component of an electrode or the like.

All. Third process plan

Zirconium (Zr) is contained 0.25 to 3.00% (weight percentage), and to the above, 0.02% to 0.50% (weight percentage) of mischmetal is added, and copper (Cu) remaining as copper (Cu) After melting the alloy, the ingot is manufactured, and the forging, rolling, extrusion, etc. are carried out at 800 to 950 ° C. with a processing ratio of 7 S (about 85%) or more to remove the cast structure of the ingot, and the thickness is 1 at 800 to 1,050 ° C. After holding at least 30 minutes per inch, the solution is quenched by quenching with water or oil, etc., and then solution-treated to maintain precipitation at 350 to 550 ° C. for at least 1 hour in order to strengthen precipitation after solution treatment. A method of producing a component such as an electrode by using the same material as it is, and completing the above process.

Hereinafter is an embodiment of the present invention.

EXAMPLE

Referring to the results of the example performed according to the first step above are as follows.

In Example, the type of alloy and each component are as shown in Table 1 below, and were cast by ingot with a thickness of 70mm.

After hot rolling at 880 ° C. with a workability of 7S (about 85%) to a thickness of 10 mm, and maintaining the solution at 960 ° C. for 1 hour, the solution solution was cold-rolled at room temperature to 1.5 mm in thickness by 85%, and then 400 After aging at 3O < 0 > C, 425 [deg.] C, 450 [deg.] C, 475 [deg.] C, 500 [deg.] C, 525 [deg.] C and 550 [deg.] C, respectively, the solution was cooled by water and subjected to age hardening heat treatment. The results are shown in Table 2 below. Table 2 also shows the case of the conventional copper (Cu) -chromium (Cr) and copper (Cu) -zirconium (Zr) binary alloys.

In Table 2, the copper (Cu) -zirconium (Zr) binary alloy shows a stable state of hardness and conductivity even when the content of zirconium (Zr) is 2.0 wt%.

Therefore, the present invention is stable in hardness and conductivity and maintains a high level as compared with the conventional copper (Cu) -chromium (Cr) binary alloy even after exposure to an aging temperature of 525 ° C or higher, that is, 525 ° C or higher. It was. In the case of spot welding electrode, the sticking effect of sticking with the welded object was remarkably improved during welding operation. This is a fine and stable precipitate, which is uniformly distributed in the base, such as cerium copper Cu _X Ce and lanthanum copper. It is considered that it is attributable to the presence of Cu _X La, niobium copper Cu _X Nd, and prassadiodium copper Cu _X Pr.

The present invention as described above is stable and high in hardness and conductivity, compared to the conventional copper (Cu) -chromium (Cr) binary alloy even after exposure to aging temperature of 525 ℃ or more, that is, 525 ℃ or more. In the case of spot welding electrodes, the sticking effect of sticking with the welded object was remarkably improved in the welding operation, and the cerium copper Cu _X Ce and lanthanum, which are fine and stable precipitates uniformly distributed in the matrix, were maintained. copper Cu _X La, you audio hatred copper such as Cu _X Nd, and plastic new audio hatred copper Cu _X Pr uniformly large amount distribution, such as to improve the resistance welding and that the durability as a contact welding electrodes of the electrical contact material and the steel sheet It works.

Claims (2)

In the electrode material for resistance welding and spot (spot) welding of an electrical contact member or a steel plate, it is 0.25-3.00% (weight percentage) zirconium (Zr), 0.02%-0.50% (weight percentage) mischmetal, And, the remainder is made of copper (Cu), but the 0.02% to 0.50% (weight percentage), the mischmetal is 50% (weight percentage) cerium (Ce) and 25% (weight percentage) lanthanum ( La), 15% (w / w) Nidium (Nd), and 5% (w / w) Prasedium (Pr) mixed composition (Cu) -zirconium (Zr) Mischmetal alloys. In the heat-treatment method of the electrode material for resistance welding and spot (spot) welding of an electrical contact material or a steel plate, it is 0.25-3.00% (weight percentage) zirconium (Zr), and 0.02%-0.50% (weight percentage) micrometals (mischmetal) ) And the remainder are prepared by dissolving a copper (Cu) alloy made of copper (Cu), and forging at 800 ~ 950 ℃ with a processing ratio of 7S (about 85%) or more to remove the cast structure of the ingot. After rolling, extrusion, etc., and maintaining it at 800 to 1,050 ° C for 30 minutes or more, such as 1 inch in thickness, quenching with water cooling, oil cooling, etc., and solution solution, and uniformly depositing a large amount of fine precipitates during aging treatment. In order to provide a large number of dislocation crossings or dense parts, which are nucleation sites for depositing, the first step is cold working such as rolling, forging, drawing, etc. at a processing rate of 70% or more at room temperature, and after cold working for 1 hour at 350-550 ° C. After maintenance, water cooling, oil cooling, air cooling, etc. Zirconium (Zr) - - miswi metal (mischmetal) processing method of the heat-treated alloy with copper (Cu), characterized in that for performing the age hardening heat treatment.