阅读说明：本技术 一种利用冷压焊接连接超窄铝带的方法 (method for connecting ultra-narrow aluminum strips by cold-pressing welding ) 是由 薛卫龙 陈刚 董福伟 于 2018-06-01 设计创作，主要内容包括：本发明公开了一种利用冷压焊接连接超窄铝带的方法,包括如下步骤：(1)对待焊铝带进行表面清洁,去除表面附着的污物、水汽,根据铝带宽度设计带矩形截面钳口的模具；(2)将铝带插入冷压焊机的模具钳口,预压紧后实现冷压焊机顶锻3～5次,压力200～300MPa,压缩量8～12 mm；(3)待完成焊接后,开模取出焊接好的铝带,去掉焊接飞边和毛刺。本发明实现了矩形截面铝带的冷压焊接,工艺简便,容易实现在线操作,而且在操作过程中,不需要额外的焊接材料和能量,不会对铝带本身的性能产生不利影响。(The invention discloses a method for connecting ultra-narrow aluminum strips by cold-pressing welding, which comprises the following steps: (1) cleaning the surface of an aluminum strip to be welded, removing dirt and water vapor attached to the surface, and designing a die with a rectangular-section jaw according to the width of the aluminum strip; (2) inserting the aluminum strip into a die jaw of a cold welding machine, and after pre-pressing, upsetting the aluminum strip for 3-5 times by the cold welding machine, wherein the pressure is 200-300 MPa, and the compression amount is 8-12 mm; (3) and after the welding is finished, opening the die and taking out the welded aluminum strip, and removing welding flash and burrs. The invention realizes the cold-pressing welding of the aluminum strip with the rectangular section, has simple and convenient process, is easy to realize online operation, does not need additional welding materials and energy in the operation process, and does not generate adverse effect on the performance of the aluminum strip.)

1. A method for connecting ultra-narrow aluminum strips by cold pressure welding is characterized by comprising the following steps:

(1) Cleaning the surface of an aluminum strip to be welded, removing dirt and water vapor attached to the surface, and designing a die with a rectangular-section jaw according to the width of the aluminum strip;

(2) Inserting the aluminum strip into a die jaw of a cold welding machine, and after pre-pressing, upsetting the aluminum strip for 3-5 times by the cold welding machine, wherein the pressure is 200-300 MPa, and the compression amount is 8-12 mm;

(3) And after the welding is finished, opening the die and taking out the welded aluminum strip, and removing welding flash and burrs.

2. the method for connecting the ultra-narrow aluminum strips by cold-press welding according to claim 1, wherein the die in the step (1) comprises a jaw and an overflow groove, the jaw is used for clamping the aluminum strips, the aluminum strips are sent to a contact surface to realize upsetting, and the overflow groove is arranged on two sides of the width direction of the flat wire of the die.

3. a method of joining ultra narrow aluminum strips by cold pressure welding as claimed in claim 2 wherein the inner surfaces of said jaws are roughened to prevent slippage of the aluminum strip within the mold.

Technical Field

The invention relates to a method for connecting ultra-narrow aluminum strips by cold-pressing welding.

Background

the helical ribbon is steam generator's key heat transfer component, and in order to guarantee the unanimity of heat exchange tube heat conduction characteristic and the thermal current at different positions even, the automated processing of the helical ribbon of being convenient for simultaneously requires that the metal strip size precision, the performance that are used for the preparation of same steam generator helical ribbon are unanimous. By combining the factors of heat conduction property, cost, processing and the like, an ultra-long (more than 20000 m) and ultra-narrow (15-20 mm) pure aluminum strip is generally adopted at present.

Internationally, the production technology of the ultra-long and ultra-narrow aluminum strip is mainly controlled in Germany and American companies, the continuous rolling technology is generally adopted for automatic production, the equipment investment is large, and related technologies and equipment are blocked in China. Therefore, no manufacturers for producing the ultra-long and ultra-narrow aluminum strip for nuclear power cooling by adopting similar technologies or introducing equipment are available at home so far. In China, manufacturers try to produce ultra-long and ultra-narrow aluminum strips by adopting an aluminum rod extrusion (Conform) technology, but the yield is low, and the strip breakage is easy to occur. Therefore, a core technical breakthrough is urgently needed to be searched, the continuity of the aluminum strip product is ensured, and a high-stability aluminum strip manufacturing technology is developed. Another idea for obtaining an ultra-long aluminum strip is to connect the aluminum strips. At present, a plurality of aluminum strip connecting technologies are suitable for connecting wide aluminum strips, mainly including resistance welding and friction stir welding, but because the two technologies have heat affected zones, the joint strength is difficult to reach the base material strength, but the technologies are difficult to apply when the requirement on the joint performance is high.

Cold pressure welding is a method of achieving solid state welding by applying pressure to cause strong plastic deformation of the metal at room temperature. The cold-press welding can quickly and simply obtain a high-quality welding structure, heating is not needed in the welding process, and the welding joint flash is small and easy to remove. The cold pressure welding technology is generally applied to the connection of wires with circular sections, only the size factor needs to be considered in the welding process, and the connection is easy to realize. The aluminum strip related to the project is of a rectangular cross section, the size and the direction of the aluminum strip need to be strictly controlled, the difficulty is obviously increased, and no report of aluminum strip connection by using the technology exists at present.

Disclosure of Invention

The invention aims to: to solve one of the above problems, a method of joining ultra narrow aluminum strips by cold pressure welding is provided.

The invention is realized by the following technical scheme:

A method for connecting ultra-narrow aluminum strips by cold pressure welding comprises the following steps:

(1) Cleaning the surface of an aluminum strip to be welded, removing dirt and water vapor attached to the surface, and designing a die with a rectangular-section jaw according to the width of the aluminum strip;

(2) Inserting the aluminum strip into a die jaw of a cold welding machine, and after pre-pressing, upsetting the aluminum strip for 3-5 times by the cold welding machine, wherein the pressure is 200-300 MPa, and the compression amount is 8-12 mm;

(3) and after the welding is finished, opening the die and taking out the welded aluminum strip, and removing welding flash and burrs.

Further, the die in the step (1) comprises a jaw and overflow grooves, wherein the jaw is used for clamping an aluminum strip, the aluminum strip is conveyed to a contact surface to realize upsetting, and the overflow grooves are arranged on two sides of the die in the width direction of the flat wire.

further, the inner surface of the jaw is rough so as to prevent the aluminum strip from slipping in the die.

In summary, due to the adoption of the technical scheme, the invention has the beneficial effects that:

the invention realizes the cold-pressing welding of the aluminum strip with the rectangular section, has simple and convenient process, is easy to realize online operation, does not need additional welding materials and energy in the operation process, and does not generate adverse effect on the performance of the aluminum strip.

Detailed Description

All of the features disclosed in this specification, or all of the steps in any method or process so disclosed, may be combined in any combination, except combinations of features and/or steps that are mutually exclusive.

Any feature disclosed in this specification (including any accompanying claims, abstract) may be replaced by alternative features serving equivalent or similar purposes, unless expressly stated otherwise. That is, unless expressly stated otherwise, each feature is only an example of a generic series of equivalent or similar features.

A method for welding and connecting ultra-narrow aluminum strips by cold pressing comprises the steps of cleaning the surfaces of aluminum strips to be welded, removing dirt, water vapor and the like attached to the surfaces, and designing a die with a rectangular-section jaw according to the width of the aluminum strips; then inserting the aluminum strip into a jaw of a die of a cold welding machine, and after pre-pressing, upsetting for 3-5 times by the cold welding machine, wherein the pressure is 200-300 MPa, and the compression amount is 8-12 mm; and opening the die after the welding is finished, taking out the welded aluminum strip, and removing welding flash and burrs.

The die selected in the cold-press welding process consists of four modules made of hot-work die steel, and is used for clamping an aluminum strip firstly and then conveying the aluminum strip onto a contact surface to realize upsetting; overflow grooves are arranged on two sides of the die in the width direction of the flat wire, so that impurities on a welding surface are easily extruded out, and flash is easily removed by dividing into two parts; in order to prevent the aluminum strip from slipping in the die during the upsetting process, the inner surface of the jaw is ensured to be rough.

the principle of the invention is as follows: under the action of external force exceeding the yield strength of the aluminum strip, the aluminum strip in the welding area is subjected to plastic deformation through a proper mould, aluminum atoms are caused to generate relative displacement, and the aluminum strip connection is realized through the direct combination of the aluminum atoms on the welding surface.

The above-mentioned embodiments are provided to further explain the objects, technical solutions and advantages of the present invention in detail, and it should be understood that the above-mentioned embodiments are only examples of the present invention and are not intended to limit the present invention. The invention extends to any novel feature or any novel combination of features disclosed in this specification and any novel method or process steps or any novel combination of features disclosed.