What electrode is used to weld stainless steel? How to weld stainless steel?

Welding is a process in which the material of the workpiece to be welded (same or dissimilar) is combined with atoms to form a permanent connection through heating or pressure or both, and with or without filling materials. So what are the points of stainless steel welding and notes? What electrode is used to weld stainless steel Stainless steel electrode can be divided into chromium stainless steel electrode and chromium nickel stainless steel electrode, these two types of electrode in accordance with the national standard, according to the national standard GB/T983-2012 provisions of the assessment. Chromium stainless steel has a certain corrosion resistance (oxidizing acid, organic acid, cavitation) heat resistance and corrosion resistance. It is usually selected for power station, chemical industry, petroleum and other equipment materials. However, under general circumstances, the weldability of chromium stainless steel is poor, so attention should be paid to the welding process, heat treatment conditions and the selection of appropriate electrode. Chromium nickel stainless steel electrode has good corrosion resistance and oxidation resistance, widely used in chemical, chemical fertilizer, petroleum, medical machinery manufacturing. In order to prevent the intergranular corrosion caused by heating, the welding current should not be too large, about 20% less than the carbon steel electrode, the arc should not be too long, the quick cooling between layers, and the narrow weld bead is appropriate. Stainless steel welding points and matters needing attention A, the use of vertical external characteristics of the power supply, DC when the use of positive polarity (welding wire is connected to the negative electrode) 1. It is generally suitable for the welding of thin plates under 6mm, with the characteristics of beautiful weld forming and small welding deformation. 2, the protective gas is argon, the purity is 99.99%. When the welding current is 50~150A, the flow rate of argon is 8~10L/min, and when the current is 150~250A, the flow rate of argon is 12~15L/min. 3. The length of the tungsten electrode protruding from the gas nozzle is 4~5mm. It is 2~3mm in the place of poor shielding, such as fillet welding, and 5~6mm in the place of deep grooving. 4. In order to prevent the occurrence of welding pores, welding parts such as rust and oil must be cleaned up. 5, welding arc length, welding ordinary steel, with 2~4mm is the best, and welding stainless steel, with 1~3mm is the best, too long is not good protection effect. 6. When butt backing, in order to prevent the back of the bottom weld pass from being oxidized, the back also needs to be protected by gas. 7. In order to protect the welding pool well with argon gas and facilitate the welding operation, the Angle between the center line of tungsten electrode and the workpiece at the welding place should generally be maintained at 80~85°, and the Angle between the filler wire and the workpiece surface should be as small as possible, generally about 10°. 8. Windproof and ventilation. In windy areas, always take measures to stop the net, and take appropriate ventilation measures indoors. Two, stainless steel MIG welding points and matters needing attention 1, the use of flat characteristics of the welding power supply, DC using the opposite polarity (welding wire is connected to the positive electrode) 2. Pure argon (purity 99.99%) or Ar+2%O2 is generally adopted, and the flow rate is 20~25L/min. 3, arc length, stainless steel MIG welding, generally under the conditions of jet transition welding, voltage to adjust to the arc length in 4~6mm. 4. Windproof. MIG welding is susceptible to the influence of wind, and sometimes the breeze produces pores, so the wind speed in the 0.5m/ SEC above the place, should take windproof measures. Three, stainless steel flux-cored wire welding points and matters needing attention 1. The flat characteristic welding power supply is adopted, and the reverse polarity is used in DC welding. Welding can be done with general CO2 welder, but the pressure of wire feeder should be slightly loosened. 2. The protective gas is generally carbon dioxide gas, and the gas flow rate is 20~25L/min. 3. The distance between the welding nozzle and the workpiece should be 15~25mm. 4. Dry extension length, the general welding current is about 15mm below 250A, and about 20~25mm above 250A is more appropriate.铜焊丝,Copper Welding Rods,铝焊丝,aluminium welding wire,镍焊条,Nickel electrode,药皮焊条,Flux Coated Brazing Welding Rods