In the fabrication of pipeline and pressure vessel , medium-thickness carbon steel and stainless steel are widely welded. According to actual fabrication conditions, submerged arc welding(SAW), argon arc welding (TIG) and plasma welding (PAW)process are the three most commonly used.
However, these three conventional processes have great limitations.
Submerged arc welding: It is impossible to realize double-sided forming on one side welding. the back of weld need clean root and reweld with a lot of noise and slag , reduce the production efficiency.
Argon arc welding: shallow depth of penetration, low deposition rate, need groove and must be multi welding, low production efficiency.
Plasma: high requirements for processing equipment, high requirements for workpiece pairs,
High requirements for operator, narrow surface weld beads, and low system cost performance.
|1||Single-side welding double-sides forming||No||Yes||Yes||Yes||Do not need root clean|
|2||Maximum penetration||8mm||3mm||10mm||16mm||High penetration|
|3||Medium plate beveling||No||Yes||No||No||Do not need filler material|
|4||Forming plate once||No||No||Yes||Yes||Faster than PAW|
|5||Beautiful surface||Yes||Yes||No||Yes||Double-side forming well|
|6||Joint gap||≤2mm||≤2mm||≤0.5mm||≤2mm||Strong error-tolerance|
|7||Consumable||Wire and flux||High wire consumption||Plasma gas||Argon||Consumables Low cost|
|8||Max welding speed||400mm/min||200mm/min||500mm/min||900mm/min||The fastest|
|9||Striking /End Defect||Yes||No||Yes||No|
|10||Rated duty cycle||60%||60%||60%||100%|
Since the limitations of the traditional process, combined with the advantages of plasma and argon arc welding, we research and develop Keyhole TIG high-efficient deep-melt argon arc welding process .
The Benefits of Keyhole TIG :
- 5-10 times faster than TIG/GTAW.
- Up to 16mm thick material in single pass, full penetration .
- Eliminates the need for joint bevelling (only square edges are needed).
- Strong error-tolerance, the gap and unfitness can reach to 2 mm.
- Without the need for filler materials.
- Eliminates the need for back gouging & cleaning.
- One surface welding two surfaces forming, can achieve convex weld without adding material, and cover both side.
- Automatic welding process and easy operation, worker can independent operate after 2 days training.
- Reduces welding labour costs.
- Low maintenance costs.
- Be capable of high weld speeds & quality with exotic materials including. stainless steel, titanium, nickel alloys, cobalt alloys and zirconium.