For T11 composition, the range of current for the
pre arc stage is 280–300 A. The I2 current is in the range 200–220 A
during which the arc is impelled along the peripheral edges of the
tubes while heating up the faying surfaces to the point of solidus
(red hot condition). Finally, the I3 current of about 1100 A during
the upsetting of the two tubes whose faying surfaces are in red hot
condition. A high current in stage III (also referred to as expulsion
current) is expected to play an important role in the cleaning action
by expelling the impurities when forging action is employed. These
specifications of current are applicable only for welding T11 tubes
of 47.6 mm diameter with 6.6 mm thickness.
MIAB welding process is divided into four stages based on the
time as specified by the manufacturer. T1 (0.5–1 s) is the time during
which the tubes, initially with a gap between them are shorted. T2
(4–6 s) is the time period in which the shorted tubes are retracted
followed by the arc striking between the tubes. Further, in this stage
of time, the arc starts to slowly rotate along the peripheral edges of
the tube ends. During this stage of time, I1 current of (280–300 A)
is employed. In stage T3 (20–30 s), arc accelerates and rotates with
a high speed of about 250 m/s (linear) along the peripheral edges
of the tubes while heating up the faying surfaces to the point of
solidus (red hot condition). A current of 200–220 A (I2 current) and
is provided during the T3 stage. Finally, upsetting action takes place
in T4 (0.3 s) by supplying a current of 1100 A (as per I3 stage).
For T11 composition, the range of current for thepre arc stage is 280–300 A. The I2 current is in the range 200–220 Aduring which the arc is impelled along the peripheral edges of thetubes while heating up the faying surfaces to the point of solidus(red hot condition). Finally, the I3 current of about 1100 A duringthe upsetting of the two tubes whose faying surfaces are in red hotcondition. A high current in stage III (also referred to as expulsioncurrent) is expected to play an important role in the cleaning actionby expelling the impurities when forging action is employed. Thesespecifications of current are applicable only for welding T11 tubesof 47.6 mm diameter with 6.6 mm thickness.MIAB welding process is divided into four stages based on thetime as specified by the manufacturer. T1 (0.5–1 s) is the time duringwhich the tubes, initially with a gap between them are shorted. T2(4–6 s) is the time period in which the shorted tubes are retractedfollowed by the arc striking between the tubes. Further, in this stageof time, the arc starts to slowly rotate along the peripheral edges ofthe tube ends. During this stage of time, I1 current of (280–300 A)is employed. In stage T3 (20–30 s), arc accelerates and rotates witha high speed of about 250 m/s (linear) along the peripheral edgesof the tubes while heating up the faying surfaces to the point ofsolidus (red hot condition). A current of 200–220 A (I2 current) andไว้ระหว่างระยะ T3 สุดท้าย upsetting กระทำเกิดขึ้นใน T4 (0.3 s) โดยการขายปัจจุบันของ A (ตามขั้นตอนของ I3)
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