When manufacturing large industrial fan structural components using welding processes, deformation is a common problem. In actual production, many factors can cause welding deformation, such as environmental conditions, construction materials, and various human factors. If the welding structure experiences deformation, it will seriously affect the quality of the entire industrial fan and even cause serious safety problems. This article will briefly analyze the main causes of welding deformation in fans and propose corresponding prevention and solution methods.
Common forms of welding deformation in large industrial fans include shrinkage, spiral, misalignment, and wave-like deformations, all of which are caused by the following reasons:
Firstly, improper temperature control during the welding process. From practice, the temperature is an important factor in steel structure welding deformation. As the temperature rises, different types of metal materials expand to different degrees when reaching the melting point. As the temperature decreases, metal contraction occurs, causing longitudinal deformation from the weld.
Secondly, improper welding sequence and construction methods during the welding process. Different positions and sequences of welding operations may lead to welding deformation. In practice, if the welding of relatively weaker load-bearing structures is carried out first, heavy loads will distort the structure, leading to welding deformation.
Thirdly, welding materials used during the welding process cause welding deformation. Different construction materials have different melting points. For example, under similar temperature conditions, different structural materials may expand to different degrees. Excessive or insufficient expansion can cause welding deformation, severely affecting the quality of welding construction.
Based on the above analysis of the causes of welding deformation, we need to take different methods to prevent and solve it. Firstly, avoid environmental factors from affecting the welding construction. The proper temperature should be maintained at the welding site. Under low-temperature conditions, preheating treatment should be applied during the steel structure welding process. The temperature instrument should be strictly monitored to ensure that the welding receives uniform heat. Control the welding process strictly.
Secondly, the welding sequence should be scientific and reasonable. The welding sequence starts from the inside and progresses outwards, from top to bottom. Adopt individual body welding first and then overall welding. The welding sequence must be strictly followed and not changed casually. During the welding process, attention should be paid to the effective welding of each node, and the quality of the weld should be strictly controlled. In case of deformation, appropriate treatment should be carried out. During the process of handling welding defects, strict inspections should be conducted. Preheating and heat preservation should be carried out equally for welding defects like welding porosity.
Thirdly, effective measures should be taken to reduce stress concentration during the welding process. To effectively pull out the arc line at the welding seam, the welder should extend the time before welding the seam so that it can be precisely cut off after the welding operation is completed. This can effectively prevent joint crack disease. During the welding process, weld the position with a relatively larger shrinkage first.
After the completion of industrial fan welding operations, different inspection tools should be used for strict inspection, such as magnifying glasses, to check for slag inclusions, blowholes, and other defects on the welding surface to avoid cracks.
Large industrial fan structures are relatively complex, and many structural components are involved in the welding process. This increases the difficulty of deformation control in welding. However, only by strictly following the production process and carrying out preventive and corrective welding deformation during the pre, ongoing, and post-stages of the welding process can we ensure the qualification of product quality.