無(wú)縫異型鋼管采用平特性焊接電源，直流焊接時(shí)采用反極性。使用一般的CO2焊機(jī)就可以施焊，但送絲輪的壓力請(qǐng)稍調(diào)松。為防止無(wú)縫異型鋼管焊接氣孔之出現(xiàn)，焊接部位如有鐵銹、油污等務(wù)必清理干凈。為使氬氣很好地保護(hù)焊接熔池，和便于施焊操作，鎢極中心線與焊接處工件一般應(yīng)保持80-85°角,填充焊絲與無(wú)縫異型鋼管表面夾角應(yīng)盡可能地小，一般為0°左右。

Flat characteristic welding power source is used, and reverse polarity is used in DC welding. The general CO2 welding machine can be used for welding, but the pressure of wire feeding wheel should be adjusted slightly. In order to prevent the occurrence of weld pore in seamless special-shaped steel pipe, it is necessary to clean up the welded parts such as rust and oil stain. In order to protect the weld pool well by argon gas and to facilitate welding operation, the tungsten pole center line and the workpiece at the welding site should generally maintain an angle of 80-85 degrees, and the angle between filler wire and the surface of seamless special-shaped steel pipe should be as small as possible, generally about 0 degrees. 無(wú)縫異型鋼管MIG焊接容易受到風(fēng)的影響，有時(shí)微風(fēng)而產(chǎn)生氣孔，所以風(fēng)速在0.5m/sec以上的地方，都應(yīng)當(dāng)采取防風(fēng)措施。干伸長(zhǎng)度，一般的焊接電流為250A以下時(shí)約5mm，250A以上時(shí)約20-25mm較為合適。電弧長(zhǎng)度，不銹鋼無(wú)縫異型鋼管的MIG焊接，一般都在噴射過渡的條件下來(lái)施焊，電壓要調(diào)整到弧長(zhǎng)在4-6mm的程度。

MIG welding of seamless special-shaped steel pipes is susceptible to the influence of wind. Sometimes breeze produces air holes. Therefore, wind-proof measures should be taken where the wind speed is above 0.5m/sec. Dry elongation is about 5 mm when welding current is below 250A and 20-25 mm when welding current is above 250A. The arc length and the MIG welding of stainless steel seamless special-shaped steel pipe are generally welded under the condition of spray transition. The voltage should be adjusted to the extent of 4-6 mm arc length.

鎢極從氣體噴嘴突出的長(zhǎng)度，以4-5mm為佳，在角焊等遮蔽性差的地方是2-3mm，在開槽深的地方是5-6mm，噴嘴至工作的距離一般不超過5mm。對(duì)接打底時(shí)，為防止底層焊道的背面被氧化，背面也需要實(shí)施氣體保護(hù)。直流時(shí)采用正極性一般適合于6mm以下的無(wú)縫異型鋼管焊接，具有焊縫成型美觀，焊接變形量小的特點(diǎn)保護(hù)氣體為氬氣，純度為99.99%。當(dāng)焊接電流為50-50A時(shí)，氬氣流量為8-0L/min，當(dāng)電流為50-250A時(shí)，氬氣流量為2-5L/min。

The length of tungsten pole protruding from gas nozzle is 4-5mm, 2-3mm in places with poor shielding ability such as fillet welding, 5-6mm in places with deep groove, and the distance from nozzle to work is generally not more than 5mm. In order to prevent the back of the bottom weld from being oxidized, gas protection is also needed on the back of the bottom weld. The positive polarity is generally suitable for the welding of seamless special-shaped steel pipes under 6mm when DC is applied. It has the characteristics of beautiful weld formation and small welding deformation. The protective gas is argon, and the purity is 99.99%. When welding current is 50-50A, the argon flow rate is 8-0L/min, and when welding current is 50-250A, the argon flow rate is 2-5L/min.