Magnetism in the weld process and its effects.
Magnetism in the weld process and its effects.
(OP)
We have a special automated welding process for welding up and making long tubes. We are trying to get a full penetration weld, and are currently at approximately 60 to 70%. These auto welders are custom made machines that compress the tube together and weld at the same time. We are experencing a tremendous amount of magnetism at the machine and repair of the tube after auto welding is excessive. Repair welders are trying to weld and magnetism is causing through back. If we eliminate the magnetism at the autowelders can we obtain 100% penetration.





RE: Magnetism in the weld process and its effects.
2.Do you have any coils of lead in the near location?
3.Could you use AC?
4.Can you wrap your electrode lead around your product?
5.You may be able to place magnets in areas that will help.
6.Can you relocate your process in regards to earth poles?
Do a web search for "arc blow". You will find other tips.
RE: Magnetism in the weld process and its effects.
Could you please describe your process in greater detail? This might help to pinpoint solution(s), as mentioned by deanc.
Is this automated process for making seam welded tubing?
What is the welding process, is filler metal used?
What is the tube material?
RE: Magnetism in the weld process and its effects.
RE: Magnetism in the weld process and its effects.
http://www.ap-automation.com/downloads/ma_brochure.pdf
http://www.millerwelds.com/education/tech_articles/articles33.php
RE: Magnetism in the weld process and its effects.
I have heard that using an AC setting for SAW will reduce magnetic arc blow affects. To answer your question - eliminating magnetism should enable you to achieve full penetration weld joints.
RE: Magnetism in the weld process and its effects.
RE: Magnetism in the weld process and its effects.
RE: Magnetism in the weld process and its effects.
Steel mesh shielding(4x8 ft sheets) to contain magnetic field.
Consider how at what part of the welding frequency cycle the arc quits. The work is magnetized twice(+ and -)for each sinewave? frequency cycle. What the last current>magnetic field is - produces the permanent magnet in the steel. If the welder stops the current when the current is not zero(ie. crossover point in the frequency cycle a permanent magnet (steel) can result.
Answer? 1. Adjust welder to shut off at crossover point in cycle.
Answer? 2. Pull arc away as weld ends
Investigate how demagnetizers work - usually AC magnetic saturation followed by decreased current until no magnetic field is left.
RE: Magnetism in the weld process and its effects.
Thanks and regards
Sayee Prasad R
Ph: 0097143968906
Mob: 00971507682668
email: sayee_prasad@yahoo.com
If it moves, train it...if it doesn't move, calibrate it...if it isn't written down, it never happened!