Stainless steel bonded pipe calls for deep penetration, no oxide addition and tiny heat impacted area, the weld joints substantially influences the formability of stainless-steel pipeline. One of the most common welding method for stainless-steel is hand welding (MMA), complied with by metal electrode gas welding (MIG/MAG) and tungsten inert gas welding (TIG).

hand-operated welding( MMA).

Manual welding is a really typical and also easy-operate welding approach, can be utilized to bond almost all materials and also any type of setting also under water. In electrode welding, the length of the arc is readjusted by hand, which is established by the size of the void between the electrode and also the workpiece. In many cases, the welding is carried out by direct existing, and also the electrode is used as both arc carrier as well as weld filler product. The electrode is composed of alloy or non-alloy metal core cord as well as electrode weldermetals cover. This layer of coating to secure the welding joint from air damages, at the same time can support the arc, the electrode can be titanium type electrode, however likewise basic, which depends upon the thickness and also structure of the covering.

MIG/MAG.

This is an automatic gas protected arc welding technique. The arc is heated between the cord of the existing provider as well as the workpiece under the securing gas, as well as the cable fed by the equipment melts under its own arc as the electrode. Due to its adaptability as well as various advantages, MIG/MAG welding is still the most commonly made use of welding approach on the planet, relevant to steel, non-alloy steel, low alloy steel as well as high alloy product. When welding stainless-steel, MAG can meet the demands of sheet steel as thick within 0.6 mm. The safety gases used right here are reactive gases such as carbon dioxide or blended gases.

Tips for stainless-steel MIG welding.

( 1) Flat qualities of the welding power supply, DC using reverse polarity (welding wire linked to the positive electrode).

( 2) Pure argon (purity of 99.99%) or Ar +2% O2, circulation price of 20|25L/min is appropriate.

( 3) Stainless steel MIG welding is normally under the conditions of jet shift welding, voltage to adapt to the arc size in 4|6mm.

( 4) Windproof: MIG welding is vulnerable to the impact of the wind to produce pores, so the wind rate above 0.5 m/s should be taken windproof actions.

( 5) Moisture-proof: exterior welding has to protect the work surface from dampness in order to make best use of the result of safeguarding gas.

TIG welding:.

The arc is produced between refractory tungsten electrode and the workpiece, which is a welding technique making use of argon, helium and also other inert gas as the shielding gas. The welding is steady and also developed well. TIG welding stainless steel with upright exterior qualities of the power supply, making use of favorable polarity when DC (welding cord is linked to the negative electrode) because it has a deep penetration capacity. TIG welding can be utilized to bond slim and medium density stainless-steel sheets, as a root hand down a thicker section.

Tips for stainless steel TIG welding.

( 1) The welding joint is good as well as the welding deformation is tiny, appropriates for the welding of stainless-steel sheet under 6mm.

( 2) Argon is a safety gas with a purity of 99.99%. When the welding current is 50|150A, the circulation rate of argon is 8|10L/min, and also when the existing is 150|250A, the flow price is 12|15L/min.

( 3) The size of the tungsten electrode from the gas nozzle to 4|5mm, in the place of fillet welding is 2|3mm, where with the deepness of the groove is 5|6mm, the range from the nozzle to the work is normally not greater than 15mm.

( 4) The rust and also oil in the welding component must be cleaned up to stop welding pores.

( 5) The arc length of 1|3mm is the most effective, and also the defense effect is bad if it is too long.

( 6) When butt backing, the rear end likewise needs gas defense in order to avoid the back of the bottom bead from oxidation.

( 7) In order to shield the welding pool well with argon and also facilitate the operation, the Angle between the center line of tungsten electrode and the workpiece at the welding website ought to usually be kept at 80|85 °, as well as the Angle between the filler cord and the workpiece surface area need to be as little as feasible, normally regarding 10 °.