Views: 1 Author: Site Editor Publish Time: 2020-02-29 Origin: Site
Aluminum pipewelding operation can be said to be a link involved in many aluminum pipe users, which directly relates to the quality level of welded aluminum pipe, and then it will inevitably be closely related to the follow-up application of specific equipment. In order to make these aluminum tubes show ideal effect, it is necessary to strengthen the control of welding forming quality.
Here is the content list:
What Are Poor Welded Aluminum Pipe Performances?
How To Prevent Defects Before Welding Aluminum Pipe?
What Should You Do After Welding Aluminum Pipe?
The appearance of welding crack is the most common aspect in the welding process of aluminum tube, and it is also a problem that has great influence on the application of follow-up metal products. This kind of welding crack is mainly manifested in two basic types: hot crack and cold crack.
Hot crack is a kind of intergranular crack that occurs when crystallizing at high temperature, so it is also called crystallization crack. This kind of crack can be observed under a microscope and has the characteristics of intergranular failure. Most of the crack sections of aluminum pipes have oxidation color. Hot cracks occur mainly in welds of aluminum pipes containing more impurities, it has both vertical and horizontal.
Cold crack refers to the welding crack that occurs when the welded joint of aluminum pipe is cooled to a lower temperature. The most common cold crack is delayed crack. The delay time of cold crack varies from several seconds to several years.
For the welding treatment of aluminum pipe, the corresponding poor welding quality is also easy to manifest as the fracture of the weld zone. Because of the poor integrity of the weld area, it is likely to lead to breakage or sudden change , which will ultimately lead to the damage of the application value of aluminum tubes.
The slag remaining in the weld after welding is called slag inclusion. Slag inclusion is a kind of solid inclusion defect. It is the molten slag remaining in the weld. According to its formation, it can be divided into linear, isolated and other forms.
Slag inclusion can reduce the plasticity and toughness of the weld of aluminum pipe, and its sharp angle often causes stress concentration, especially in the weld of aluminum pipe with high air quenching tendency, cracks are often formed at the tip of the sharp angle. Often, under the action of stress, cracks appear at the slag inclusion in the weld of aluminum pipes, which leads to the decrease of strength and the cracking of weld.
The undercut of aluminum pipe will reduce the actual working area of the weld, easily produce stress concentration and reduce the strength of the weld. Welding forming and undercutting defects are caused by improper operation of welders. For example, too high welding voltage and too fast welding speed of aluminum tube will cause the above defects. In view of the defects of welding forming and undercutting, enterprises should improve the welding skills and quality of welders, and strictly control the welding products.
Ensure clean environment
The slag inclusion defect in aluminum pipe welding is mainly due to the cleaning of weld groove or oxide pollutants produced by welding wire. In view of the slag inclusion defect, the welding groove of aluminum pipe should be cleaned up in time, the welding environment should be controlled, and the impurities should be avoided from entering the weld.
When inspecting the undercut of the aluminum tube, the main ruler is used to close to one side of the weld, and then the height ruler is moved to the other side which just touches the weld. The measured height is the biting quantity, which should be controlled according to the standards and actual needs.
If gas welding or flux-coated electrode welding is used, it is necessary to remove the residual flux and slag from the weld seam and both sides of the aluminum pipe in time before the appearance inspection and non-destructive inspection of the weld seam of the aluminum pipe are carried out, so as to prevent the welding slag and residual flux from corroding the weld seam and its surface of the aluminum pipe and avoid adverse consequences.
Through proper welding technology and correct operation technology, the welded surface of aluminum pipe has a uniform and smooth appearance. High quality decorative aluminum tube surface can be obtained by anodizing treatment, especially polishing and dyeing technology.
Postweld heat treatment
The purpose of post-weld heat treatment is to improve the structure and properties of welded aluminum tube joints or to eliminate residual stresses.
Above is the analysis and suggestion on the poor welding quality of aluminum tube. Each welding method has its own application occasion. I hope it will be helpful to you. If you want to buy high quality aluminum tubes, you may as well try our products, which will certainly give you a different feeling.