Copyright (c) 2001-2002 Guido Walt, guido.walt@wear-management.ch

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\h2
{Applications}

\p
{MIG / MAG Processes can be used for both joining and coating applications, whether for the protective coating
 of new parts or the build-up and repair of parts.}

\h2
{Storage of continuous electrodes}

\p
{In particular, care must be taken in the storing of continuous electrodes to protect them from contamination,
 oxidation, rust, etc., causing feeding difficulties through the lining, and other harmful effects including
 increased electrical resistance at the torch contact tube.\n
 Damage through rough handling and inadequate storage may produce poor electrode feed, current fluctuations,
 control problems, oxide inclusions or porous deposits.}

\h2
{Preparation of base materials}

\item
{For optimum results worn components should be cleaned and properly prepared prior to welding.}
{Components which have been in service may exhibit damaged and / or fatigued areas. Fatigue cracks will more likely
 contain  other contaminants.}
{Damaged areas should be dressed by grinding or gouging.}
{It is important that all contaminants be removed before welding.}
{Sharp edges can be prepared by removing these areas to form a radius (this will
 reduce overheating and uncontrolled dilution).}

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{Shielding gas}

\p
{The choice of shielding gas will affect all the following:}

\item
{Temperature distribution in the arc}
{Arc characteristic and droplet transfer}
{Arc stability}
{Arc shape}
{Depth of penetration}
{Deposit geometry}
{Risk of porosity}
{Mechanical properties}

\img
{img/processes/gasmigmage.png} {}
{Influence of the various constituent gases}


\h2
{Short arc and spray arc: Parameter setting}

\item
{Select the welding voltage on the welding source}
{Regulate the welding current via the wire speed potentiometer adjustable from 0 to 10, 15, 20 or more m/min.\n
 The motor of the MIG / MAG wire-feeder is powered by an adjustable voltage.\n
 The speed is therefore adjustable but constant during welding.\n
 The amperage adjustments necessary for stabilising the arc are made by the power source.}

\h2
{Pulsed arc: Parameter setting}

\item
{Select the parameters for pulsation voltage on the welding source}
{Regulate the welding current via the wire speed potentiometer adjustable from 0 to 10, 15, 20 or more m/min.\n
 The motor of the MIG / MAG wire-feeder is powered by an adjustable voltage.\n
 The speed is therefore adjustable but constant during welding.\n
 The amperage adjustments necessary for stabilising the arc are made by the power source.}

\img
{img/processes/pulsee.png} {}
{Pulsed arc: Parameters for pulsation voltage}

\item
{Base voltage is necessary for maintaining the arc during cold phase. Typical values: min. 10 V ( min 20 A )}
{Pulse voltage controls the current pulsation. Higher pulsating voltage increases the heat input to the weld pool.
 Typical values: max. 40 V ( max. 500 A )}
{Pulse duration: A longer pulse duration increases the heat input, and also influences the diameter of
 the droplets in formation. Typical values: 1 to 15 ms.}
{Frequency: Higher frequency increases the heat input, as well as the number of droplets transferred per unit of time.
 Typical values: 30 to 300 Hz.}
{Wire feed speed: Higher wire feed speed has a particular influence on the deposition speed. Higher feed speed requires
 higher pulse frequency.}

\inc
{contactus}