Factors of weld defects

(1) Material factors:

The so-called material factor refers welding base metals and welding materials used, such as wires, rods, flux, and the shielding gas and the like. All of these materials are directly involved in the welding puddle or physico-chemical reaction of the fusion zone, where the base material of the good performance of the material itself, dual-zone heat shadow attack decisive impact. On the composition and properties of the weld metal is also a key factor in the welding material is clearly used. Good fruit and base metal welding materials mismatch, not only can cause a variety of defects in the weld zone to the lines, pores, etc., and may also be available from embrittlement, corrosion-resistant properties to soften or change. Therefore, in order to ensure good weld joints must be full attention to material factors.

(2) Technological factors:

A lot of practice has proved that the same kind of base metal in different welding methods and process measures conditions, the welding quality will show a big difference. Affect the quality of the welding method of welding main possible in two aspects: First, the characteristics of the welding heat source, which is the power density, the maximum heating temperature, power level, etc., they can change the parameters of the welding thermal cycle directly, such as the line of energy, high-temperature residence time, the phase transition temperature range of the cooling rate. These of course will affect the microstructure and properties of joints; secondly to the pool and the nearby area of ​​protection, such as slag protection, gas, gas – slag joint protection or welding in a vacuum, which will affect the process of welding metallurgy. Obviously, the process of welding thermal and metallurgical processes for quality and performance will inevitably joints decisive impact.