tailieunhanh - Submerged Arc Welding Episode 2

Tham khảo tài liệu 'submerged arc welding episode 2', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Bonded Fluxes Bonded fluxes are made from raw materials that are powdered dry mixed and bonded together with either a potassium silicate or sodium silicate binder or a combination of both. The wet bonded mix is pelletized and baked at low temperature. When drying is complete the pellets are broken up screened for particle sizing and packaged for shipment. Bonded fluxes offer these advantages 1 Easy addition of deoxidizers and alloying elements fused fluxes achieve this with great difficulty because of separation or loss 2 Allows a thicker flux layer when welding and 3 Can be identified by color. The disadvantages of bonded fluxes are that they absorb moisture like Shielded Metal Arc electrode coatings and they can change in flux composition from segregation or loss of fine particle size. Agglomerated Fluxes Agglomerated fluxes are produced similar to bonded fluxes with these exceptions A ceramic binder is used. A higher drying temperature is also used which limits the use of deoxidizers and alloy elements similar to the fused fluxes. Advantages and disadvantages are similar to those of bonded fluxes. Mechanically Mixed Fluxes A mechanically mixed flux is achieved by mixing two or more fluxes bonded or agglomerated fluxes to get the desired properties. These mixed fluxes have the advantage of using readily available commercial fluxes for mixture in higher critical weld situations. Disadvantages of mixed fluxes are Segregation during shipping storage and handling segregation in flux feeding and recovery systems and inconsistent mixtures from one mix to the next. Particle Size Flux particle sizes are important because they influence flux feeding recovery weld bead shape appearance and weld current levels. As amperage is increased the average flux particle size should decrease. Some flux manufacturers provide literature giving the mesh sizing along with the amperage suitable for that mesh sizing. Too high a current for a particle flux size will cause an unstable arc .