Detailed explanation of multi-layer and multi pass welding process parameters

1、 Overview of multi-layer and multi pass welding process

Multi layer and multi pass welding technology is an efficient and high-quality welding method suitable for large structures. It is mainly used for welding large structures such as ships, bridges, and high-rise buildings, which can greatly improve welding efficiency and on-site safety. In multi-layer and multi pass welding processes, the thickness of the weld seam is generally required to be at least 8mm, and the number of weld beads is generally at least 5. Therefore, the multi-layer and multi pass welding process requires high precision in the welding process.

2、 Parameter settings for multi-layer and multi pass welding

1. Welding current

Welding current is the main parameter that affects welding strength and welding speed. Its setting needs to be determined based on the thickness of the welding material and the position of the weld seam. When the thickness of the material being welded is large, it is necessary to increase the welding current to ensure the penetration depth of the weld. When the thickness of the material being welded is relatively thin, it is necessary to reduce the welding current to avoid excessive melting of the weld seam.

2. Welding voltage

Welding voltage is also an important parameter that affects welding quality. Generally speaking, excessive welding voltage can cause excessive melting of the weld seam, resulting in too many protrusions and indentations between the welds; If the welding voltage is too low, it will lead to insufficient penetration depth of the weld seam. Therefore, when setting the welding voltage, factors such as the type of welding material, welding thickness, and welding speed need to be considered.

3. Welding speed

Welding speed is also an important parameter that affects welding quality and efficiency. Excessive welding speed can lead to incomplete melting of the weld seam, insufficient welding strength, as well as defects such as welding burrs and pores; If the welding speed is too slow, it will increase the welding time and cost, and also make the welding process affected by the external environment, thereby affecting the welding quality.

4. Welding electrodes

Suitable welding electrodes are one of the key factors in achieving multi-layer and multi pass welding processes. When selecting welding electrodes, it is necessary to determine based on factors such as the type, thickness, and stress state of the material being welded. Generally speaking, the diameter of the welding electrode should be smaller than the diameter of the welding rod in order to better control the welding process and welding quality.

3、 Summary

In multi-layer and multi pass welding processes, setting welding parameters is one of the key factors to ensure welding quality and efficiency. In practical applications, it is necessary to flexibly set parameters based on specific situations to achieve optimal welding quality and cost-effectiveness. At the same time, regular welding quality inspections and timely adjustment of welding parameters can effectively improve welding quality and reduce welding costs.