ThyssenKrupp Tailored Blanks Ltd. Since 1985, production welded blanks, laser welding technology makes the car manufacturing emerged from the vehicle manufacturers to transfer material suppliers. Currently, laser Welding Electrode plate mainly used in automobile manufacturing. In laser welding, the material is docking rather than overlapping, which will bring the following weld characteristics:
(1) reduce the volume of the weld area, for example, welding width of not more than 0.5 ~ 1mm; (2) does not increase the height of the weld; (3) little effect on the performance of metal forming; (4) attached to zinc in the weld, may maintain its cathodic protection; (5) welding process, the heat affected zone is small.
After completion of welding, welding on the static and dynamic strength is a very important indicator, therefore, need to weld area sampling, the destructive tensile strength test (cupping test) to test the weld zone of the stretch forming performance. In general, the tensile strength of the weld strength than the base metal is higher.
Tailored blanks lap spot welding process and the traditional craft has many advantages compared to the product: not only reduces the cost of vehicle manufacturing, logistics costs, vehicle weight, assembly tolerance, rate of fuel consumption and waste, and reduce the external reinforcement the number of steps and simplified assembly process, while the collision the vehicle capacity enhancement, and the corrosion rate of metal forming ability increased. In addition, avoid the use of sealants, but also for environmental benefits.
â‘ Welding Electrode selection of a wide range of basic principles, each electrode has certain characteristics and uses. In order to ensure product quality, increase productivity and reduce production costs, must be the correct selection of electrode. The actual selection electrode, in addition to considering economic, construction conditions, the welding efficiency and working conditions, it should consider the following principles:
a. For the principle of equal strength to withstand static load or load the workpiece or the general structure, usually by weld and base metal electrodes such as strong selection principle, which called for weld and base metal tensile strength equal or similar.
b. Conditions according to the principles of the workpiece or the working conditions of welded structures and characteristics of the selection electrode. If the welding under dynamic load or impact load of the workpiece should be used in high impact toughness of deposited metal alkaline electrode; and in the general structure of welding, the electrode can be used acidic.
c. Equivalence principle in the special working environment welded structure, such as corrosion, high temperature or low temperature, in order to ensure that performance should be based on the deposited metal and base metal properties of the same or similar principles of selection of welding rod.
â‘¡ Carbon Steel Welding Rod selection According to China's steel rod standard, currently the main use of carbon electrode is E43 and E50 series series models. Mild steel welding, generally acidic electrode structure can be used, under dynamic load or complex thick-walled structures and low temperature when used with alkaline electrode, as shown in Table 2-2; carbon steel welding, as compared with carbon high, prone to weld cracking, and thus should be used in alkaline electrode or the weld metal with good ductility and toughness of the electrode, should be warm and gentle cold processing, as shown in Table 2-3; high-carbon steel welding, welding consumables The selection of product design requirements should be considered, depending on when the high strength requirements, available J707 (E7015-G) or J607 (E6015-G) electrode, while the strength is not critical, the choice of J506 (E5016) or J507 (E5015 ) electrode.
â‘¢ low-alloy steel welding electrodes used steel hot rolling and normalizing, based primarily on ensuring the weld metal strength, ductility and toughness and other mechanical properties to match with the base metal and welding a large thickness of the component, in order to prevent the generation of welding cracks , can be "low-intensity matches," the principle that selection of weld metal strength is lower than the base material of the electrode. Welding low-carbon quenched and tempered steel, the hydrogen should be strictly controlled, and therefore generally used in low-or ultra-low hydrogen type hydrogen electrode. Quenched and tempered carbon steel welding, in order to ensure that the weld metal ductility, toughness and strength, improving crack resistance, low-carbon alloy system should be used, to minimize the weld metal sulfur and phosphorus impurities.