In recent years, the application of low alloy and high strength materials in special equipment has become more and more common, which is related to the working condition of high temperature and high pressure of boiler and pressure vessel. However, cracks are often found in the welding seam after heat treatment in the manufacturing process…
1) Welding sequence. The principle of spherical tank welding sequence is to reduce the welding residual stress as much as possible. Generally, the equatorial belt is welded first, then the electrode plate is welded. First weld longitudinal seam, then weld ring seam; First, weld one side of the big groove (the outside side), and then…
(1) Arc ignition — arc welding ignition When welding with alkaline electrode, in the process of arc initiation, due to less slag, less protective gas in the arc, so that the pool protection effect is not good, the weld is very easy to appear dense pores, mostly N2 pores. In order to prevent the occurrence…
Welding is a process in which the material of the workpiece to be welded (same or dissimilar) is combined with atoms to form a permanent connection through heating or pressure or both, and with or without filling materials. So what are the points of stainless steel welding and notes? What electrode is used to weld…
Common gas mixtures are as follows: 1. The advantages of Ar+He argon are very stable arc combustion and minimal spatter. The advantages of helium gas are high arc temperature, large heat input of base metal and fast welding speed. Using argon as the matrix and adding a certain amount of helium, the advantages of both…
Why is thorium tungsten, the most widely used electrode, so popular? Thorium tungsten electrode for argon arc welding tungsten needle has excellent comprehensive performance. Can withstand overload current; Long service life, oxidation resistance, not easy to deformation; Easy to start arc, continuous arc in the welding process, arc stability, not scattered arc. But I’m sure…
Selection of welding joint coefficient Φ welded joint coefficient refers to the butt welded joint strength and ratio of material strength, to reflect due to factors such as weld defects and welding residual stress in welding joint strength is weakened, is a comprehensive reflection of welded joint mechanical properties. The weld joint coefficient shall be…
Heat-resistant steel refers to steel that has both thermal stability and thermal strength under high temperature conditions. Thermal stability refers to the ability of steel to maintain chemical stability (corrosion resistance, non-oxidation) under high temperature conditions. Thermal strength means that steel has sufficient strength at high temperatures. The heat resistance is mainly guaranteed by alloy…
Welding characteristics ① Compared with the fixed pipe, it is easy to operate and ensure the weld quality; ② It can be continuously welded with high efficiency; ③ Additional turning device is required; Welding position ① Vertical welding position: it can ensure good root fusion and penetration, and is suitable for the situation with small…
What is the nature of welding? Welding is a method of joining two separated solids by heating or pressurizing, or by heating and pressurizing. The essence of welding is metallurgical combination, that is to say, the two workpieces are combined by the combination force between atoms, and the crystal structure of the connecting part of…
