Automatic welding machine welding process considerations


Welding is a part of the rapid heating and cooling process, the welding machine area due to the constraints around the workpiece body can not be freely expanded and shrunk, after cooling in the weld will have welding stress and deformation. Important products need to eliminate the welding stress after welding, welding distortion correction. Modern welding technology has been able to weld out no defects inside and outside, the mechanical properties equal to or even higher than the welded joints. The mutual position of the body to be welded is called the welded joint. The strength of the joint is affected by the quality of the welded joint, but also with the geometry, size, force situation and working conditions. The basic form of joint docking, lap, T-then (orthogonally connected) and angle and so on. The cross-sectional shape of the butt joint weld depends on the thickness of the welded body before welding and the groove form of the two adjacent edges. Welding thick steel plate, in order to penetrate the edge in the open out of the bevel of various shapes, in order to more easily into the electrode or wire. Groove form of single-sided welding groove and both sides of the welding groove. Select bevel form, in addition to guaranteeing welding should also consider the convenience of welding, filler metal less welding deformation and beveling low cost and other factors. Thickness of the two plates of steel butt, in order to avoid sharp changes in cross-section caused serious stress concentration, often thicker edge of the board gradually thinning, reaching two edge at the same thickness. The butt joint static strength and fatigue strength higher than the other joints. In alternating, impact load or work in low temperature and pressure vessel connection, often preferred to use butt joint welding. Lap lap welding preparation work is simple, easy assembly, welding deformation and residual stress is small, so the site to install joints and not important structure often used. In general, lap joints are not suitable for alternating load, corrosive media, high temperature or low temperature and other conditions. The use of T-joints and corner joints is usually due to structural needs. T-shaped joints on the penetration of fillet weld job characteristics and lap joints fillet welding similar. When the weld is perpendicular to the direction of the external force, it becomes a positive fillet weld. At this time, the weld surface shape will cause different degrees of stress concentration. The fillet welded fillet weld is similar in force to the butt joint. Angle joint bearing capacity is low, generally not alone, only when welding penetration, or both inside and outside have a fillet weld improvement, mostly used in the closed structure of the corner. Welded products are lighter than riveted parts, castings and forgings, reducing weight and saving energy for transportation vehicles. Sealing good welding, suitable for manufacturing all kinds of containers. The development of joint processing technology, welding and forging, casting, can be made of large, cost-effective cast-welded structure and forging welding structure, high economic benefits. The use of welding technology can effectively use materials, welding structure can be used in different parts of different performance materials, give full play to the advantages of various materials, to achieve economic, high quality. Welding has become an indispensable and increasingly important processing method in modern industry. In modern metalworking, welding is more advanced than forging and forging process, but the development speed is very fast. The weight of the welded structure accounts for about 45% of the steel production, and the proportion of the welded structure of the aluminum and aluminum alloy is also continuously increasing. Future welding process, on the one hand to develop new welding methods, welding equipment and welding materials to further improve the welding quality and safety and reliability, such as improving the existing arc, plasma arc, electron beam, laser and other welding energy; the use of electronic technology And control technology to improve the arc of the process performance, development of reliable and lightweight arc tracking method. On the other hand to improve the level of welding mechanization and automation, such as welding machine to achieve program control, digital control; developed from the preparation process, welding quality control to the full automation of the process of welding machine; in automatic welding machine, to promote and expand CNC welding robot And welding robots, can improve the level of welding production, improve the welding hygiene and safety conditions