Comparison of single-sided and double-sided welding of SSAW steel pipe

The production process of SSAW (Spiral Submerged Arc Welding) steel pipes influences the quality of welds in single-side and double-side welding through various factors, including welding current, welding speed, number of welding layers, electrode type, and electrode diameter. Here’s a detailed look at these factors.

1. Welding Current

The choice of welding current is crucial for achieving high-quality welds:

Excessive Welding Current: While it increases productivity and penetration depth, it can cause defects such as undercutting, excessive spatter, and porosity. This is particularly problematic in vertical welding where controlling the molten pool is more difficult.

Insufficient Welding Current: Leads to shallow penetration, resulting in defects like incomplete penetration, poor fusion, slag inclusion, and cracking. Beginners often struggle with finding the right balance, which is essential to avoid these issues.

2. Welding Speed

Welding speed is a key parameter for welding efficiency and quality:

High Welding Speed: Can result in insufficient heat in the weld pool, causing defects such as incomplete penetration, non-fusion, and poor weld formation.

Low Welding Speed: Causes prolonged exposure to high temperatures, leading to a wider heat-affected zone, coarser grain structure, reduced mechanical properties, increased deformation, and slag inclusions due to backflow.

3. Number of Welding Layers

The number of welding layers affects the structural integrity of the weld:

Too Few Layers: Thick layers can lead to poor plasticity and increased risk of slag backflow, resulting in slag inclusions and poor fusion.

Too Many Layers: Thin layers might not provide sufficient fusion on both sides of the weld, leading to weak welds.

4. Electrode Type and Diameter

The electrode’s properties significantly impact weld quality:

Electrode Type: The choice of electrode should match the base metal's properties to ensure compatibility and strength.

Electrode Diameter: A large diameter can make it difficult to control the weld pool, especially in the base layer, increasing the likelihood of defects such as incomplete penetration and poor weld formation.