2.0MM-5.0MM Submerged ARC Welding Wire Pretreatment of welding method
Welding before cleaning: 2.0MM-5.0MM Submerged ARC Welding Wire welding, welding should be strictly removed before the workpiece weld and wire surface oxide film and oil;
1) chemical cleaning chemical cleaning efficiency, quality and stability, suitable for cleaning wire and small size, mass production of the workpiece. Available in both immersion and scrubbing methods. Can be acetone, gasoline, kerosene and other organic solvent surface to the oil, with 40 ℃ ~ 70 ℃ 5% to 10% NaOH solution alkaline wash 3min ~ 7min (pure aluminum time longer but not more than 20min), rinse with flowing water, 30% HNO3 solution at room temperature to 60 ℃ pickling 1min ~ 3min, flowing water rinse, dry or low temperature drying.
2) mechanical cleaning: large size in the workpiece, the production cycle is longer, multi-layer welding or chemical cleaning and then stained, often using mechanical cleaning. First with acetone, gasoline and other organic solvents to wipe the surface to degrease, followed by a direct diameter of 0.15mm ~ 0.2mm copper brush or stainless steel wire brush brush, brush to expose the metal luster so far. Generally should not use grinding wheel or ordinary sandpaper grinding, so as not to stay in the metal surface sand, welding into the molten pool to produce slag and other defects. In addition can also use scraper, rasp and other cleaning to be welding surface.
2.0MM-5.0MM Submerged ARC Welding Wire should be re-processed if it is stored for too long (if more than 24 hours).
2, the pad: 2.0MM-5.0MM Submerged ARC Welding Wire strength at high temperatures is very low, liquid aluminum flow performance is good, in the welding of weld metal prone to collapse phenomenon. In order to ensure that the penetration and not collapse, welding often use pad to hold the pool and the nearby metal. Plate can be used graphite plate, stainless steel plate, carbon steel plate, copper or copper rods and so on. The plate surface opens a circular groove to ensure that the weld is formed on the back side. But also can not be coated on the single-sided welding double-sided molding, but requires the welding operation skilled or take the arc welding energy strict automatic feedback control and other advanced technology measures.
3, preheating before welding: thin, small pieces of aluminum generally do not have to warm, the thickness of 10mm ~ 15mm can be preheated before welding, according to different types of 2.0MM-5.0MM Submerged ARC Welding Wire preheating temperature can be 100 ℃ ~ 200 ℃, can be oxygen-acetylene flame, electric furnace or torch, etc. heating. Preheating can reduce the deformation of the weldment, reducing the pores and other defects.
Some 2.0MM-5.0MM Submerged ARC Welding Wire contains low boiling point alloy elements that are susceptible to evaporation at high temperatures, altering the chemical composition of the weld metal and reducing the performance of the welded joint. In order to compensate for these burns, in the adjustment process at the same time, often contain the use of these elements with higher boiling point than the parent metal wire or other welding materials.
Heat treatment enhanced 2.0MM-5.0MM Submerged ARC Welding Wire (such as hard aluminum) connector corrosion reduction is obvious, the more uneven the joint organization, corrosion resistance easier to reduce. The purity or compactness of the weld metal also affects the corrosion resistance of the joint. The corrosion resistance will be significantly decreased, not only the local surface corrosion and often intergranular corrosion, in addition to 2.0MM-5.0MM Submerged ARC Welding Wire, the existence of welding stress is also An important factor affecting corrosion resistance.
2.0MM-5.0MM Submerged ARC Welding Wire When welding from solid to liquid, there is no obvious color change, so the welding process to the operator to bring a lot of difficulties. Therefore, the welders need to master the welding temperature of the heating, as far as possible the use of flat welding, in the lead (extinguished) arc board on the lead (extinguished) arc and so on.