Welding Process of Mild Steel Tube

Overview of mild steel tube

Mild steel is widely used in various precision equipment and engineering structures due to its good weldability. During the welding process, appropriate welding process and precautions can effectively ensure the quality of the weld.

Welding process

1. Gas welding

Gas welding is a traditional welding method suitable for low carbon steel repair and welding of some positions. Gas welding requires heating with an oxyacetylene flame and then welding with a welding pipe. The advantages of gas welding are low cost and simple equipment, but the welding speed is slow and the welding quality is poor.

2. Arc welding

Arc welding is a common welding method, usually carried out by tungsten arc welding, hand-cranked arc welding, submerged arc welding and other methods. During the arc welding process, the electrode discharges and heats the workpiece, and at the same time, it is joined by welding wire. The advantages of arc welding are low cost, fast welding speed, high welding quality, and it is widely used in factory production.

3. Submerged arc welding

Submerged arc welding is a semi-automatic welding method. The welding wire needs to be placed before welding, and then the electrode is used to heat and melt the welding wire for connection. The advantages of submerged arc welding are fast welding speed, uniform welding, good quality, and can be applied to high-pressure pipelines and other fields.

4. Argon arc welding

Argon arc welding is a commonly used TIG welding method, which is suitable for welding mild steel thin plates and pipelines. Argon arc welding requires the use of argon gas for protection, and the welding wire is melted by tungsten arc heating for joining. The advantages of argon arc welding are high welding quality, smooth welds, and small welding heat-affected zone, but it requires high technical requirements and is relatively expensive.

Welding precautions

1. Preheating and post-weld heat treatment

Mild steel tubes are prone to cold cracking and hot cracking. Preheating and heat treatment are required before and after welding to make the steel uniform in structure and temperature distribution, reducing the possibility of cracks.

2. Welding joint preparation

Before welding, the joint needs to be cleaned and grooved, and impurities in the welding area need to be cleaned to keep the weld in the best condition.

3. Choose suitable welding materials

Commonly used welding materials for low-carbon steel pipes include welding pipes, welding wires, etc., and suitable welding materials need to be selected according to the specific welding process to ensure welding quality.

4. Pay attention to welding speed and temperature

Welding speed that is too fast or too slow will affect the quality of the weld. It is necessary to select the appropriate welding speed and temperature according to the specific material and process.

Solutions

1. Welding void problem

If voids occur, you can choose to increase the electrode current or improve the surface quality of the steel.

2. Welding crack problem

You can increase the preheating temperature and welding speed, change the welding sequence and other methods to avoid welding cracks.

Conclusion

The welding process of mild steel tube needs to select appropriate processes and methods according to specific materials and requirements. During the welding process, it is necessary to pay attention to factors such as welding preparation, welding speed and temperature, and solve problems that may occur during the welding process. Through appropriate welding methods and precautions, the high quality and stability of the weld of the welded pipe can be guaranteed.