Welding stainless steel with welding consumables:
Stainless steel welding electrodes can be divided into chromium stainless steel welding electrodes and chromium-nickel stainless steel welding electrodes, these two types of welding electrodes where in line with the national standard, are in accordance with the provisions of the national standard GB/T 983-2012 assessment. Chromium stainless steel has a certain corrosion resistance (oxidizing acid, organic acid, cavitation) heat and corrosion resistance. Usually selected as power station, chemical, petroleum and other equipment materials.
Chromium-nickel stainless steel electrode has good corrosion resistance and oxidation resistance, widely used in chemical industry, fertilizer, petroleum, medical machinery manufacturing. In order to prevent corrosion, the welding current should not be too large, fast cooling between layers, to narrow the welding channel is appropriate.
Stainless steel welding technology is mainly used in the metal base material, commonly used arc welding, argon arc welding, CO2 shielded welding, oxygen - acetylene welding, laser welding, electroslag pressure and so on a variety of non-metallic materials such as plastics can also be welded.
Metal welding method has more than 40 kinds, mainly divided into fusion welding, pressure welding and brazing three categories:
1, fusion welding is in the welding process will be the interface of the workpiece will be heated to a molten state, do not add pressure to complete the welding method.
2, pressure welding is under pressure, so that the two workpieces in the solid state to achieve inter-atomic bonding, also known as solid-state welding.
3, brazing is the use of metal materials than the melting point of the workpiece as a brazing material, the workpiece and brazing material heated to higher than the melting point of the brazing material, lower than the melting point of the workpiece temperature, so as to realize the welding method.
Stainless steel welding points, precautions
One, the use of vertical external characteristics of the power supply, DC with positive polarity (wire connected to the negative pole)
1, generally suitable for the welding of 6mm or less thin plate, with a weld molding beautiful, welding deformation of a small amount of characteristics.
2, protective gas for argon, purity of 99.99%.
3, tungsten electrode from the gas nozzle protrudes from the length of 4 ~ 5mm is preferred, in the corner welding and other poorly shaded places is 2 ~ 3mm, in the grooving of deep places is 5 ~ 6mm, the nozzle to the work of the distance is generally not more than 15mm.
4, in order to prevent the emergence of welded gas holes, the welded parts of the rust, oil, etc., such as clean up.
5, welding arc length, welding stainless steel, to 1 ~ 3mm is good.
6, docking bottoming, the back also need to implement gas protection.
7, in order to make argon well protected welding pool, tungsten pole centerline and welding workpiece should generally maintain 80 ~ 85 ° angle, filler wire and workpiece surface angle is generally about 10 °.
8, wind and air exchange.
Two, stainless steel flux-cored wire welding points and considerations
1, the use of flat characteristics of the welding power supply, DC welding with reverse polarity. The use of general CO2 welding machine can be welded, but the pressure of the wire feed wheel, please slightly loose.
2, the shielding gas is generally carbon dioxide gas, gas flow rate of 20~25L/min is more appropriate.
3, the distance between the welding nozzle and the workpiece is 15~25mm.
4, dry extension length, the general welding current of 250A below about 15mm, 250A above about 20~25mm is more appropriate.