The welding process and chemical metallurgical properties of sintered flux for roller repair are one of the main factors that determine the chemical composition and properties of weld metal. Using the same welding wire and welding process parameters, using different flux, the performance of welding metal will be very different. In low carbon steel and low alloy steel, the welding wire can be reasonably combined with a variety of fluxes.
1. The sintered flux should have good metallurgical properties. With proper welding wire and reasonable welding process, the welding metal should be able to obtain proper chemical composition and good mechanical properties (strength and high plasticity and toughness, compatible with base metal), and have strong cold crack and hot crack resistance.
2. The flux should have good working performance, stable arc combustion, suitable melting point, viscosity and surface tension. Weld bead and weld bead, weld bead and base metal complete fusion, smooth transition, no obvious undercut, easy slag removal, good weld surface forming, less harmful gas produced in the welding process.
3. The flux also has a certain particle size and a certain particle strength, so that it can be recycled for many times. Its particle size can be divided into two types: the particle size of ordinary flux is 2.5-0.45mm (8-40 mesh), which is used for ordinary submerged arc welding and electroslag welding; the particle size of fine flux is 1.25-0.28mm (14-60 mesh), which is suitable for semi-automatic or fine wire submerged arc welding. The fine particles below 60 mesh are less than 5%, and the coarse particles above 14 mesh are less than 2%.