Sectional form shape
Square
Suitable current/A
200 300
180 270
200 400
300 400
350 450
400 500
450 550
500 600
~
~
~
~
~
~
~
~
Carbon rod standard /mm
3×12×355
4×8×355
4×12×355
5×10×355
5×12×355
5×15×355
5×18×355
5×20×355
Table 14-3-1: Carbon rod standard and suitable current
•
Gouging speed
Gouging speed influences dadoing size, surface quality and stability during gouging. Gouging speed should in accordance
with current and depth of dadoing (or angle between carbon rod and work piece). If gouging speed is too quick, it is easy to
cause short circuit between carbon rod and metal, arc extinguish, carbon inclusion. Usually gouging speed is better around
0.5~1.2m/min.
• Pressure of compressed air
Pressure of compressed air can directly influence gouging speed and dadoing surface quality. If pressure is high, can
improve gouging speed and dadoing surface smooth degree; if pressure is low, easy to cause slag inclusion on dadoing
surface. Usually pressure is 0.4~0.6Mpa. Moisture content and oil content in compressed air can be taken by filter unit
installed in compressed air pipeline.
• Extension length of carbon rod
Extension length is carbon length from tip to end of carbon rod. In manual CAC-A, extension length is long, tip of
compressed air is far from arc, cause lack of wind power, can not blow off slag, and carbon rod is easy to break. Usually
extension length is better 80~100mm, along with carbon rod burn, extension length becomes shorter, when extension length
decreases to 20~30mm, should adjust it back to 80~100mm.
• Angle between carbon rod and work piece
Angle “a” between carbon rod and work piece mainly influences dadoing depth and gouging speed. When angle increases,
then gouging depth increases, gouging speed decreases. Usually in manual CAC-A, angle is better around 450.
ound 450.
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