As a soldering material, the self shielded flux cored wire is not protected by an applied gas during the welding operation. The gas generating agent is located inside the welding wire, which can make the internal gas pressure in the welding process too large, push the metal droplets to the outside, generate a large splash, and the generated gas will not effectively surround the metal droplets, so that the oxygen and nitrogen are very Easy to invade the weld zone.
In view of this protective property of the self shielded flux cored wire, too much gas-generating agent should not be added to the core, but is usually protected by means of a slagging agent, a deoxidizer and a nitride forming element. Generally, there are three types of pores generated in the weld, the first one being co2 and co. Since a large amount of deoxidizer is added to the self-shielded flux-cored wire, the deoxidizer has a strong affinity with oxygen and can be preferentially oxidized, which can effectively remove such pores in the weld.
The second type is a nitrogen gas well, but this is generally negligible in self shielded flux cored wire containing more strong deoxidizing nitrogen. The third type is a hydrogen hole. Due to the large amount of fluoride added to the core, hydrogen pores are rare in the weld.
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