Welding is a process in which the material of the workpiece to be welded (the same or different) is heated, pressurized or both, and whether the filler material is used is selected to make the material of the workpiece achieve the combination between atoms and form a long-time connection. So what are the key points and precautions of stainless steel welding?

1、焊不銹鋼用什么焊條或焊絲？

1. What kind of welding rod or wire is used to weld stainless steel?

不銹鋼焊條可分為鉻不銹鋼焊條和鉻鎳不銹鋼焊條，這兩類焊條中凡符合國標的，均按國標GB/T983-2012規定考核。

Stainless steel electrodes can be divided into chromium stainless steel electrodes and chromium nickel stainless steel electrodes. In these two types of electrodes, those that meet the national standard shall be assessed according to the provisions of the national standard GB / t983-2012.

鉻不銹鋼具有一定的耐蝕（氧化性酸、氣蝕）和耐熱性能，通常被選作電站、化工、石油等設備材料。但鉻不銹鋼一般情況下可焊性較差，應注意焊接工藝、熱處理條件及選用合適的電焊條。鉻鎳不銹鋼焊條具有良好耐腐蝕性，廣泛應用于化工、化肥、石油領域。為防止由于加熱而產生晶間腐蝕，焊接電流不宜太大，比碳鋼焊條小20%左右，電弧不宜過長，層間快冷，以窄焊道為宜。

Chromium stainless steel has certain corrosion resistance (oxidizing acid, cavitation) and heat resistance. It is usually selected as equipment materials for power station, chemical industry, petroleum and so on. However, the weldability of chromium stainless steel is generally poor. Attention should be paid to the welding process, heat treatment conditions and the selection of appropriate electrodes. Chromium nickel stainless steel electrode has good corrosion resistance and is widely used in the fields of chemical industry, chemical fertilizer and petroleum. In order to prevent intergranular corrosion due to heating, the welding current should not be too large, which is about 20% smaller than that of carbon steel electrode. The arc should not be too long and the interlayer should be cooled quickly. Narrow weld bead is appropriate.

2、不銹鋼焊接要點與注意事項

2. Key points and precautions for stainless steel welding

一、采用垂直外特性的電源，直流時采用正極性（焊絲接負極）

1、 The power supply with vertical external characteristics is adopted, and the positive polarity is adopted in DC (the welding wire is connected to the negative pole)

1、一般適合于6mm以下薄板的焊接，具有焊縫成形美觀，焊接變形量小的特點。

1. It is generally suitable for the welding of thin plates below 6mm, with the characteristics of beautiful weld formation and small welding deformation.

2、保護氣體為氬氣，純度為99.99%。當焊接電流為50~150A時，氬氣流量為8~10L/min，當電流為150~250A時，氬氣流量為12~15L/min。

2. The shielding gas is argon with a purity of 99.99%. When the argon flow is 150 ~ 15L / min, the argon flow is 150A ~ 15L / min.

3、鎢極從氣體噴嘴突出的長度，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，噴嘴工作的距離一般不超過15mm。

3. The length of tungsten electrode protruding from the gas nozzle is preferably 4 ~ 5mm. It is 2 ~ 3mm in the place with poor shielding performance such as fillet welding, 5 ~ 6mm in the place with deep groove, and the distance from the nozzle to the working is generally no more than 15mm.

4、為防止焊接氣孔出現，焊接部位如有鐵銹、油污等務必清理干凈。

4. In order to prevent the occurrence of welding pores, the welding parts must be cleaned if there is rust, oil stain, etc.

5、焊接普通鋼時，焊接電弧長度以2~4mm為佳；而焊接不銹鋼時，以1~3mm為佳，過長則保護效果不好。

5. When welding ordinary steel, the length of welding arc is 2 ~ 4mm; When welding stainless steel, it is better to use 1 ~ 3mm. If it is too long, the protection effect is not good.

6、對接打底時，為防止底層焊道的背面被氧化，背面也需要實施氣體保護。

6. During butt backing, in order to prevent the back of the underlying weld bead from being oxidized, the back also needs to be protected by gas.

7、為使氬氣很好地保護焊接熔池，和便于施焊操作，鎢極線與焊接處工件一般應保持80°~85°角，填充焊絲與工件表面夾角應盡可能小，一般為10°左右。

7. In order to protect the welding pool well with argon and facilitate the welding operation, the tungsten electrode line and the workpiece at the welding position shall generally maintain an angle of 80 ° ~ 85 °, and the included angle between the filler wire and the workpiece surface shall be as small as possible, generally about 10 °.

8、防風與換氣。有風的地方，務請采取擋網的措施，而在室內則應采取適當的換氣措施。

8. Windproof and ventilation. Where there is wind, please take measures to block the net, and take appropriate ventilation measures indoors.