With the rapid development of modern manufacturing industry, sheet metal parts have been widely used in various fields. As one of the sheet metal parts, round arc sheet metal parts have a complex shape and high requirements for strength, which bring certain challenges to welding. This article aims to explore the welding methods for round arc sheet metal parts, providing reference for technicians in related fields.
I. Characteristics of Round Arc Sheet Metal Parts
Round arc sheet metal parts have the following characteristics:
1. Complex shape: Round arc sheet metal parts have a complex shape with a large curvature, making it difficult to position the weld seam. To solve this problem, auxiliary tools such as templates and fixtures can be used for positioning.
2. High precision requirement for size: Round arc sheet metal parts are often required to cooperate with other parts in practical applications, so they have high requirements for size accuracy.
3. High strength requirement: Due to the large load that round arc sheet metal parts need to bear during use, they have high strength requirements.
II. Difficulties and Solutions in Welding Round Arc Sheet Metal Parts
There are several difficulties in welding round arc sheet metal parts:
1. Difficulty in positioning the weld seam: Due to the complex shape of round arc sheet metal parts, positioning the weld seam is difficult. To solve this problem, auxiliary tools such as templates and fixtures can be used for positioning.
2. Large welding deformation: Round arc sheet metal parts are prone to large deformation during welding, affecting their size accuracy and appearance quality. To reduce welding deformation, segmented welding can be used, where the round arc sheet metal part is divided into several segments and welded together, and then the segments are welded together. In addition, preheating and post-heat treatment can also be used to reduce welding stress and deformation.
3. Difficulty in ensuring weld quality: Due to the large curvature of round arc sheet metal parts, it is difficult to ensure the quality of the weld seam. To improve the weld quality, high-quality welding methods such as gas shielded welding and submerged arc welding can be used. At the same time, strict control of welding process parameters such as current, voltage, and welding speed is necessary.
4. Low welding efficiency: Due to the difficulty of welding round arc sheet metal parts, the welding efficiency is low. To improve the welding efficiency, automated and intelligent welding equipment such as robotic welding and laser welding can be used. These welding methods have high welding speed and accuracy, which can effectively improve the welding efficiency.
III. Welding Methods for Round Arc Sheet Metal Parts
To address the difficulties in welding round arc sheet metal parts, the following welding methods can be used:
1. Segmented welding method: The round arc sheet metal part is divided into several segments for welding, and then the segments are welded together. This method can effectively reduce welding deformation and improve weld quality. When segmented welding, attention should be paid to the connection mode between each segment, such as butt joint and corner joint.
2. Preheating and post-heat treatment method: Preheating the round arc sheet metal part before welding can reduce welding stress and deformation. Post-heat treatment after welding can further eliminate residual stress and improve weld quality. The temperature and time of preheating and post-heat treatment need to be adjusted according to specific materials and process requirements.
3. Gas shielded welding and submerged arc welding method: These two methods have high quality of the weld seam and are suitable for the welding of round arc sheet metal parts. When using gas shielded welding, attention should be paid to the selection and flow control of protective gas; when using submerged arc welding, attention should be paid to the selection of wire feed and control of welding parameters such as power and speed.
4. Robotic welding and laser welding method: These two methods have high welding efficiency and accuracy, suitable for large-scale round arc sheet metal parts. When using robotic welding, programming control of robot movement trajectory and welding parameters is necessary; when using laser welding, control of laser beam power, speed, etc. is necessary.
IV. Inspection and Evaluation of Weld Quality for Round Arc Sheet Metal Parts
To ensure the quality of welding for round arc sheet metal parts, strict inspection and evaluation are necessary. The inspection methods mainly include visual inspection and non-destructive testing (NDT). Visual inspection mainly observes surface defects such as shape, color, and porosity of the weld seam; NDT mainly uses ultrasonic or radiographic methods to detect internal defects of the weld seam. The evaluation methods mainly include strength evaluation of the weld seam and size evaluation of the weld seam. Weakness evaluation of the weld seam mainly tests its mechanical properties such as tensile strength and yield strength through tension, bending, etc.; size evaluation of the weld seam mainly measures its width, depth, etc. to evaluate its size accuracy.
