| 摘要 |
FIELD: methods for controlling ignition of welding electric arc at manual welding by means of coated electrode after breaking of short circuit between electrode and part. ^ SUBSTANCE: method comprises steps of touching welded part with electrode in place of welded seam beginning; exciting electric arc at time moment of electrode and part disconnection; detecting time moments of electrode and part touching and disconnection respectively by measuring changes of electric current and voltage in between electrodes. Electric arc is excited by three stages. At first in time moment of electrode and part touching short initial mode of hot starting sufficient for heating electrode is realized. After first time period short circuiting limitation mode is created when electric current value is sufficient for sustaining electrode in heated state without increasing contact area and close sticking. It provides controlled electrode sticking. At time moment of electrode tearing off secondary mode of hot starting with increased electric current is realized and electric arc is ignited between electrodes. Short initial hot starting mode is realized at electric current consisting 1.5 - 2 of preset welding current; duration of said initial hot starting mode is in range 0.5 - 1.0 s. Electric current value in short circuiting mode is selected in range 0.1 - 0.3 of preset welding current. ^ EFFECT: enhanced reliability of electric arc ignition process. ^ 6 cl, 3 dwg |
