Magnetic arc blow

One of our Singapore clients gave us feedback about the welding problems when they used the Nelweld 6000 to weld our shear studs. “Your studs are OK, the ceramic ferrules are also OK, and we weld as per Nelweld’s settings, why does this happen?” 

This is called the magnetic arc blow in the welding field. This post will share some ideas for this item.

Ps: Maybe some guys are also interested in the Nelweld 6000’s settings.

Nelweld 6000 Settings

What is the magnetic arc blow?

According to the Wikipedia, magnetic arc blow or “arc wander” is the deflection of welding filler material within an electric arc deposit by a buildup of magnetic force surrounding the weld pool.  Arc blow is the, usually unwanted, deflection of the arc during arc welding. There are two types of arc blow commonly known in the electric welding industry: magnetic and thermal.

In the arc stud welding field, the axis of the arc column deviates from the axis of the stud, this phenomenon is called arc blow.

Why the magnetic arc blow occur?

Magnetic arc blow can occur because 1)Workpiece connection, 2) Joint design, 3) Poor fit-up, 4) Improper settings, 5) Atmospheric conditions. Normally there are some magnetic in the surroundings, such as the electromagnetic field of the metal sheet; the amount of ferromagnetic material distribution and welding clamp cable magnetic field.

Magnetic arc blow cause 1
Magnetic arc blow cause 2
Magnetic arc blow cause 3

How to prevent the magnetic arc blow?

Arc blow is proportional to current intensity and can be influenced by symmetrically attaching mass clamps and compensating masses, or (in the case of hand guns with an external welding cable) by turning the gun around the vertical axis. Arc blow generates one-sided melting and can increase the number of pores in the welded materials, but it can be reduced by suitable application of different remedies.

Magnetic arc blow remedy 1
Magnetic arc blow remedy 2

After our suggestion, the Singapore client solves the magnetic arc blow problems.

Sino Stone has a powerful technical engineer team who can slove almost all drawn arc stud welding problems, if you encounter some problems about shear stud welding, please feel free to contact us: [email protected]