Refrigerator refrigerant leakage reveals the aluminum row welding

[China Aluminum Network] The leakage of refrigerant in cold storage is a headache for many refrigeration engineering companies, distributors, and customers. The leakage of refrigerant and the aluminum row are inextricably linked. Many details of the aluminum row will directly affect whether the refrigerant will cause leakage problems. The specific details include: welding process, surface treatment process, tube wall Thickness, material selection, etc. Today, the Refrigeration Express reporter will share with you the effect of the aluminum row welding process on refrigerant leakage problems.

There are many kinds of welding metal processes on the market, such as: welding, resistance welding, gas welding, brazing, plasma arc welding, electron beam welding, vacuum diffusion welding, tungsten arc welding, etc. Suitable welding processes for aluminum (aluminum) welding processes include gas welding and tungsten arc welding. What are the differences between these two welding processes?

Gas welding refers to a welding method in which a flame generated by the combustible combustion of a combustible gas and a combustion-supporting gas is used as a heat source to melt the weldment and the welding material so as to achieve the combination of atoms. It is mainly used for the welding of materials such as thin steel plates and low melting point materials (non-ferrous metals and their alloys), including aluminum row products. The advantages of gas welding are: simple equipment, flexible operation, good adaptability to welding of cast iron and certain non-ferrous metals, and gas welding can play a greater role in places where power supply is insufficient. The disadvantages of gas welding are: low production efficiency; the deformation and heat affected zone of the workpiece after welding are large, resulting in welding welding slag piles and messy surfaces; it is difficult to achieve automation.

Then, what impact does the gas welding have on the application of aluminum row welding? The Refrigeration Express reporter specifically consulted with senior aluminum emission expert Mr. Liu Zhenyuan. He explained to the reporter that when using the gas welding process to weld the aluminum row, the combustion gas is mainly oxygen, combustible gas. Mainly uses acetylene, liquefied petroleum gas, etc., so its flame's thermal power is low, the heated area is large, the heat is relatively dispersed, the weldment is easily deformed, the temperature is high during the welding process, and the weld metal after welding not only disperses crystals, but also has loose structure. It will also allow the aluminum at the weld joint to chemically react to change the molecules and produce inclusions of alumina. This will cause defects such as blowholes and cracks, which will cause aluminum traps to have a hidden problem of airtightness. Jiahui directly causes the leakage of refrigerant in the cold storage. The leakage of refrigerant can lead to the collapse of the entire refrigeration system. If the relevant goods are stored in the cold storage, the associated loss is inestimable. At the same time, there is a risk that the solder remains in the aluminum tube during the welding process, which may lead to blockage of the tube and result in failure of the refrigeration system to function normally.

Tungsten pulse argon arc welding refers to the use of continuous, uninterrupted base current (also known as the arc current) to maintain the main arc ionization channel, and periodically apply a pulse of the same polarity and high peak pulse current, with To melt the metal, control the transition of the droplet to achieve the purpose of welding. Tungsten Pulse Argon Arc Welding Features: It can accurately control the heat input to the workpiece and the size of the weld pool, improve the ability of the welding seam to resist burn-through and weld pool, easy to obtain a uniform penetration depth, especially for thin plates (thin to 0.1mm ) All-position welding and single-sided welding double-sided molding; each welding point heating and cooling quickly, so suitable for welding workpieces with large thermal conductivity and thickness difference; pulsed arc can use a lower heat input to obtain greater penetration Therefore, under the same conditions, the welding heat affected zone and welding deformation can be reduced; during the welding process, the molten metal in the bath pool condenses quickly and the high-temperature residence time is short, which can reduce the tendency of the heat-sensitive material to crack when welded.

Mr. Liu Zhenyuan, a researcher of Tungsten Pulse Argon Arc Welding, conducted a detailed analysis of the advantages of the process when welding aluminum strips: As argon has excellent protection, it can effectively isolate the surrounding air, argon itself. It neither chemically reacts with metal nor dissolves in metal, making it possible to obtain higher quality welds when welding aluminum rows, and without any chemical changes at the welds, resulting in good gas tightness; tungsten arc very stable Even in the case of very low current (<10A), it can be stably burned, especially for thin aluminum welding. Since the heat source and filler wire can be separately controlled, the heat input is easy to adjust, so this welding method can be used for all-round welding. It is a high-quality process for double-sided forming of single-side aluminum welding. Because the filler wire does not pass current, it does not produce spatter. The welded out aluminum welding seam is beautiful in shape; AC argon arc welding can automatically remove the surface of the weldment during welding. The oxide film function, therefore, can successfully weld non-ferrous metals with strong chemical reactivity such as aluminum; the use of argon is more expensive, the deposition rate is low, and the argon arc welding machine has more complicated phases. In gas welding, the high cost of production.

Mr. Liu Zhenyuan went on to analyze that, in the operation of technicians, gas welding is easier to use than TIG welding. The gas welding process requires only one day of training to go on duty. Tungsten pulse argon arc welding requires at least three trainings. Only by months can start, it takes three years to fully master the process, which is also an important reason for the aluminum row manufacturers to choose the welding process. Basically, gas welding can not be automated now, and tungsten pulsed argon arc welding may be automated. For example, the frost source aluminum row produced by Xingtai City Frost Source Refrigeration Equipment Co., Ltd. is now used. Pulse argon arc welding process, the company is currently working with a professional organization in Tianjin, to do tungsten electrode pulse argon arc welding automated process research, is expected to be automated by the end of this year, will completely solve the welding process production efficiency problems.

The aluminum row welding process is very important to ensure that the refrigerant in the refrigeration system does not leak, and the aluminum row surface treatment process is also closely related to the problem of refrigerant leakage. The high-quality surface treatment process can not only prevent the refrigerant from leaking but also extend the life of the aluminum row by more than three years. This intangible brings great joy to the stable operation and post-maintenance of the cold storage system. What are the differences in the specific surface treatment process of aluminum row? Welcome everyone to continue to pay attention to the topic of aluminum fog - aluminum surface treatment mist.