Submerged arc welding defects, seeking help.
Thread Content
In the submerged arc welding of the boiler drum in a boiler factory, the entire weld seam, including its center, is at a relatively high level. What’s the reason for this? Additionally, there are relatively large pores on the surface of the weld seam; what causes these and how can they be prevented? There are also fairly large deep defects inside the weld seam – how do these arise? Sometimes there are also inclusion defects within the weld; no bevel is used for 12mm thickness, and welding is done layer by layer. What could be the reason? Thank you
Is there any issue with the manufacturing process? Or maybe there is no welding process involved； Do welders have the certification for welding pressure vessels? ； Environmental temperature, humidity, whether there is wind indoors or outdoors, and the properties of the welding wire and flux, etc ； Generally, a groove is made, the surface is cleaned and the root area is cleaned after welding; the current and voltage are adjusted properly, and welding is carried out at a constant speed with preheating... Any failure to follow these steps properly will affect the quality of the weld.
The welding current is high and the voltage is too low. The flux is damp, the welding wire is not clean, and the interior has not been properly cleaned
The welding process is fine; it’s just 20-mm-thick steel plates, the welders all have the necessary certifications, and the ambient temperature is above 5°C.
The cracks are all at a depth of about 1 mm on the surface.
Are there any pictures of cracks in the equipment? Including them in the topic edit will make them more noticeable and facilitate analysis.