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    Arc Blow

    Uploaded by

    Amrut Kajve
    Arc Blow in welding is one of the major problem. this presentation includes mechanism of arc blow, causes and remedies related to arc blow.

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    © All Rights Reserved
    Download as PDF, TXT or read online from Scribd

    Arc Blow

    Uploaded by

    Amrut Kajve
    305 views9 pages
    Arc Blow in welding is one of the major problem. this presentation includes mechanism of arc blow, causes and remedies related to arc blow.

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    Arc Blow.pptx

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    © © All Rights Reserved

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    Arc Blow in welding is one of the major problem. this presentation includes mechanism of arc blow, causes and remedies related to arc blow.

    Copyright:

    © All Rights Reserved
    Download as PDF, TXT or read online from Scribd
    Download as pdf or txt
    305 views9 pages

    Arc Blow

    Uploaded by

    Amrut Kajve
    Arc Blow in welding is one of the major problem. this presentation includes mechanism of arc blow, causes and remedies related to arc blow.

    Copyright:

    © All Rights Reserved
    Download as PDF, TXT or read online from Scribd
    Download as pdf or txt
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    ARC BLOW

    What is an Arc Blow


    Welding arc deflects away from the point of welding under
    some circumstances. Such arc deflections forward or
    backward is called Arc Blow.

    Causes for Arc Blow

    Unbalanced condition in magnetic Field.


    Residual magnetism in the material (job).

    Circumstances causing Arc Blow


    ARC BLOW Occurs in:
    DC welding.
    Magnetic materials [ due residual magnetism].
    Caused by interaction between directional magnetic field
    of welding arc and directional field of the residual
    magnetism.
    Magnetic field strength is greater than 50 Gauss causes
    arc blow [Thumb Rule].

    Effects of Arc Blow on Welding

    Arc Blow occurs in DC arc welding.


    Causes Arc Deflection.
    Excessive Spattering.
    Lack of fusion.
    Porosity.
    Poor weld quality.

    Arc Blow Mechanism

    Unbalanced condition in the magnetic field.


    The concentric flux fields will remain circular when they can stay in
    one medium large enough to contain them until they diminish to
    essentially nothing.
    if the medium changes, the circular lines of force are distorted and
    tend to concentrate in the steel where they encounter less resistance.
    Causes deformation in the circular lines of flux.
    This squeezing can result in a heavy concentration of flux behind or
    ahead of a welding arc.
    The arc then tends to move in the direction that would relieve the
    squeezing and restore the magnetic field balance.

    Magnetic field around the electrode

    Change in Magnetic Field

    Methods to avoid arc blow


    Use as short an arc length as possible (lower arc voltage) and
    the lowest current that is practical for the affected joint
    (possibly a smaller diameter electrode).
    Weld towards the return or earth connections.
    Use of multiple earth connections may solve the problem
    altogether.

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