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、焊不锈钢用什么焊条或焊丝？

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

不锈钢焊条可分为铬不锈钢焊条和铬镍不锈钢焊条，这两类焊条中凡符合国标的，均按国标GB/T983-2012规定考核。

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.

铬不锈钢具有一定的耐蚀（氧化性酸、气蚀）和耐热性能，通常被选作电站、化工、石油等设备材料。但铬不锈钢一般情况下可焊性较差，应注意焊接工艺、热处理条件及选用合适的电焊条。铬镍不锈钢焊条具有良好耐腐蚀性，广泛应用于化工、化肥、石油领域。为防止由于加热而产生晶间腐蚀，焊接电流不宜太大，比碳钢焊条小20%左右，电弧不宜过长，层间快冷，以窄焊道为宜。

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、不锈钢焊接要点与注意事项

2. Key points and precautions for stainless steel welding

一、采用垂直外特性的电源，直流时采用正极性（焊丝接负极）

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、一般适合于6mm以下薄板的焊接，具有焊缝成形美观，焊接变形量小的特点。

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、保护气体为氩气，纯度为99.99%。当焊接电流为50~150A时，氩气流量为8~10L/min，当电流为150~250A时，氩气流量为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、钨极从气体喷嘴突出的长度，以4~5mm为佳。在角焊等遮蔽性差的地方是2~3mm，在开槽深的地方是5~6mm，喷嘴工作的距离一般不超过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、为防止焊接气孔出现，焊接部位如有铁锈、油污等务必清理干净。

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

5、焊接普通钢时，焊接电弧长度以2~4mm为佳；而焊接不锈钢时，以1~3mm为佳，过长则保护效果不好。

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、对接打底时，为防止底层焊道的背面被氧化，背面也需要实施气体保护。

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、为使氩气很好地保护焊接熔池，和便于施焊操作，钨极线与焊接处工件一般应保持80°~85°角，填充焊丝与工件表面夹角应尽可能小，一般为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、防风与换气。有风的地方，务请采取挡网的措施，而在室内则应采取适当的换气措施。

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