Submerged Arc Welding Machine: Core Technology and Industry Applications of High - Efficiency Automated Welding Equipment

 

As an automated device that achieves welding by burning an electric arc under a flux layer, the submerged arc welding machine is an indispensable high - efficiency welding solution in industrial production. Its core technology, through the dual effects of concentrated release of arc heat energy and flux protection, significantly improves welding efficiency and quality, and is widely used in fields such as shipbuilding, bridge construction, and chemical equipment manufacturing.

 

I. Principle and Workflow of Submerged Arc Welding Technology

The workflow of the submerged arc welding machine can be divided into four stages: arc ignition, wire feeding, deposition, and finishing. During welding, the arc burns stably under the covering of granular flux, and the welding wire is continuously fed into the molten pool. The base metal and the welding wire are fused at high temperatures to form a dense weld. The flux layer not only isolates the air to prevent oxidation and nitridation but also participates in the metallurgical reaction through the molten slag to optimize the weld composition. The core technological advantages are as follows:

1. High thermal efficiency and large penetration: The conductive length of the welding wire is short, and the current density can reach more than 5 times that of traditional manual welding. The penetration of a single - pass weld can reach 20 mm, significantly reducing the need for groove machining.

2. Full - process automated control: Parameters such as wire feeding speed, arc voltage, and welding speed can be precisely adjusted through the mechanical system to ensure process stability.

 

II. Analysis of Core Advantages

1. Breakthrough improvement in production efficiency

The deposition rate of submerged arc welding can reach 8 - 12 kg/h, which is 3 - 5 times that of manual arc welding. Taking the butt welding of 20 - mm - thick steel plates as an example, single - side welding with double - side forming can be achieved without grooving, saving more than 60% of working hours. For continuous welds of large - scale structural parts (such as ship hull assembly), the device can work continuously for more than 8 hours, reducing the frequency of manual intervention.

2. Industry - leading weld quality

The molten slag layer effectively isolates oxygen and nitrogen. The nitrogen content in the weld metal is controlled below 0.002%, and the fluctuation range of mechanical properties is less than 30% of that of traditional welding processes. Industrial test data shows that the tensile strength deviation of submerged arc welding joints does not exceed 5%, significantly better than the industry standard.

3. Significant improvement in the production environment

There is no visible arc radiation during the welding process, and the smoke emission is reduced by 80% compared with CO₂ gas shielded welding. The working environment meets the ISO 15012 - 1 occupational health standard. This characteristic makes it particularly suitable for long - term operations in confined spaces and large workshops.

 

III. Industry Applications and Material Compatibility

Currently, submerged arc welding technology mainly serves four major fields:

- Heavy - industry manufacturing: Welding of ship sections and circumferential seams of nuclear power pressure vessels.

- Energy infrastructure: Spiral welding of oil and gas pipelines and manufacturing of wind turbine towers.

- Special - material processing: Welding of high - strength steel (grades Q690 and above) and surfacing of nickel - based alloys.

- Construction engineering: Automatic welding of H - shaped steel in steel structures of super - high - rise buildings.

 

In terms of material compatibility, the optimization of the combination of welding wire and flux should be focused on:

- Carbon - steel welding: It is recommended to use H08A welding wire with HJ431 high - manganese and high - silicon flux.

- Treatment of low - temperature steel: Use medium - manganese flux with Mn - Mo alloy welding wire.

- Stainless - steel welding: Select alkaline sintered flux and ER308L series welding wire.

 

IV. Key Points of Key Operation Techniques

1. Pre - welding preparation: The edges of the steel plates need to be mechanically processed or precisely gas - cut, and the assembly misalignment must be controlled within 10% of the plate thickness. For workpieces with a thickness of more than 40 mm, it is recommended to pre - heat to 120 - 150 °C to reduce the risk of cold cracking.

2. Matching of process parameters: For every 100 A increase in welding current, the average penetration increases by 1.2 mm. The typical parameter configuration is: when the plate thickness is 12 mm, the current is 680 - 720 A, the voltage is 34 - 36 V, and the welding speed is 25 - 30 cm/min.

3. Flux management: The covering thickness of the flux is recommended to be maintained at 30 - 50 mm. When recycling and reusing, it is necessary to sieve to remove slag particles and ensure that the particle size is in the range of 0.5 - 2 mm.

 

V. Technological Innovation and Development Trends

With the upgrading of the manufacturing industry, submerged arc welding technology is making breakthroughs in three directions:

1. Digital control: Introduce an adaptive parameter adjustment system to monitor the molten pool state in real - time and automatically compensate for process parameter fluctuations.

2. Environmental - friendly flux: Develop fluorine - free and low - hydrogen flux, reducing the content of toxic substances in welding fumes to below 0.1 mg/m³.

3. Multi - process combination: The submerged arc - TIG hybrid welding technology can double the welding speed of aluminum alloys compared with traditional methods.

Currently, the annual consumption of flux in China is about 50,000 tons, and the proportion of non - smelting flux has increased from 20% to 35%, which is expected to exceed 50% in the next five years. In the total amount of steel welding, submerged arc welding still maintains a stable proportion of more than 10% and continues to dominate the field of thick - plate welding.