Technology

Electrode feeding system in Submerged Arc Welding

For semi-automatic welding, the CV system is used to keep the feed rate constant, and the CC system is used to monitor the arc pressure and adjust the electrode feeding speed to maintain pressure. in the arc is constant A simple electrode feeding system is performed by turning the knob to stabilize the feeding speed. They are used in both CV and CC systems for controlled feeding distances. Microprocessor is used for CV only.

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Weld Head

Welding head assembly for under-fluxed or submerged welding. It consists of a motor driving the feeder and winding of the wire. There are also welding nozzles (Torch) and flux nozzles. The wire feed motor has a gear reducer to adjust the feeding speed to 8 – 235 mm/s. The welding head has a guide tube to support the wire into the welding tip in the area where an arc will occur.

Other accessories such as

  1. Mobility aids The movement speed should not exceed 45 mm/s (in the weld line).
  2. Flux suction unit to use in order to use the flux for maximum benefit. It will perform the following functions:

2.1 Eliminate undissolved flux and slag at the back of the weld.

2.2 Separate dissolved slag and large material.

2.3 Remove magnetic substances.

2.4 Recirculate the usable flux back to the Hopper.

2.5 Heat the flux in the Hopper to reduce humidity.

position control system

due to under-fluxed or submerged welding There will be a limitation, which is to be connected in a horizontal position only. Therefore, it is necessary to use a repositioning device to achieve the desired weld line.

Related materials Commonly used metals for welding are:

    – Carbon Steel with % of C up to 0.29%

    – Low Alloy Steel (Yield Strength up to 690 M/A)

    – Chromium – Molybdenum Steel (0.5 – 9 % of Cr, 0.5 – 1 % Mo)

    – Stainless Steel

    – Nickel alloy

Electrode

The electrode used is a bare wire made of alloy and stored in coils. For steel wire, there is a copper coating. This increases the service life, reduces wear on the electrode guides and increases the conductivity Electrode sizes range from 1.6 – 6.4 mm.

Flux

It is a granule of minerals that contains many ingredients according to the desired properties as follows.

Fused Flux is produced from various raw materials mixed together in an electric furnace. Then it will be prepared to the desired size.

Advantages of Fused Flux

      – High homogeneity

      – not hygroscopic

      – Can be recycled easily due to consistent size

      – Easy removal of irrelevant substances

Disadvantages

      – The addition of anti-oxidation and Ferro alloy during production is difficult. which will cause a lot of loss

      – Use high temperature in production

Bened Flux is produced from a variety of powdered raw materials mixed together using Potassium Silicate and/or Sodium silicate to form a homogeneous bond. It is then mixed and baked at a lower temperature than the Fused Flux and produced to the desired shape.

strength

    – Easy to fill with Anti-Oxidation and Ferro alloy.

    – Use color as a classifier

    – Make the layer of flux thicker while welding

Disadvantages

    – tends to absorb moisture easily

    – Gas may be generated from molten slag.

    – In sorting, the flux may change its properties as smaller ingredients are removed.

Mechanical Mixed Flux uses Fused Flux and Bended Flux mixed in the desired proportion.

strength

– Qualifications required in special welding processes

weakness

    – Separation occurs during transportation, storage and handling.

    – Isolation occurred in the recovery system.

    – Unstable ingredients

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