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PATON
ProMIG series
DC MMA/TIG/MIG/MAG
results in somewhat worse arc striking. See paragraph 6.1 for sequence of changing
the value of any function in the current welding mode
3.8 PULSED CURRENT WELDING FUNCTION
This function is designed to facilitate control over welding process in spatial
positions other than downhand position, as well as during welding of non-ferrous
metals. This function affects directly weld metal dilution and metal drop transfer
into the weld pool and, consequently, on stability of weld forming and of the welding
process. In other words, this process substitutes movements of welder's hand to
some extent, which is especially important in hard-to-reach places. Correct setting
determines weld shape and quality of weld forming, thus reducing risk of porosity
and grain structure of the weld and consequently increasing weld strength.
In order to implement this functions, three parameters must be set in the
machine: pulsing power [Po.P], pulsing frequency [Fr.P] and mark-to-space ratio (or
duty ratio) [dut]. By default, pulsing power [Po.P], which is the key parameter, is set
to "OFF" position, i.e. disabled, while pulsing frequency [Fr.P] and duty ratio [dut]
are set to most common values of 50 Hz and 50% respectively. In order to enable
this function, it is enough to set pulsing power [Po.P] to a value above zero. This
parameter is set in percent of current set value of base arc welding.
Example: welding with a Ф3 mm electrode, set base value of arc current is 90 A,
and pulsing power [Po.P] = 40%, while pulsing frequency [Fr.P] = 50 Hz and duty
ratio [dut] = 50% by default.
Result: current will pulse in the range from 54 A to 126 A with frequency of 50
Hz, pulses will be of the same shape in terms of both magnitude and time. If duty
ratio parameter [dut] is changed to a value other than 50%, pulses become
asymmetric, but the machine calculates pulsing in such a way that, at constant set
differential of pulses, average level of arc current is maintained at the level of set
base arc current value of 90 A (i.e. equal to the set value), in order to keep the
resulting average heat input into the weld at a constant level. This is necessary in the
situation, when a user has reduced base current and provided maintenance of stable
welding process using pulses
–
thus, decrease of heat input can be also clearly
determined by comparison with initial base current.
These parameters are set differently in different situations in accordance with
welding operator's requirements. See paragraph 6.1 for sequence of changing the
value of any function in the current welding mode
