JPS55165292A - Electroslag welding method and same welding equipment and sliding copper backing for same welding - Google Patents

Abstract

PURPOSE:To make the measurement and controlling of the depth of the molten slag bath easy by forming a groove in the sliding copper backing in the electroslag welding equipment, inserting a resistor therein by way of an insulator and connecting the electrode provided therein and copper backing terminal to a control circuit. CONSTITUTION:A groove 4' is provided in the surface of a sliding copper backing 4 toward the groove and a resistor 11 is inserted therein by way of an insulator 10 to bury terminal electrodes 12, 13. These two electrodes and the terminal 3 of the backing 4 are connected to a control circuit 14, and the electric current flowing between the two electrodes 12, 13 from an electric power source 14' is corresponded to the depth of a slag bath 5. Here, the deeper the depth of the slag bath 5 is and the lower the position of the Q point where the molten slag 5 makes direct contact with the resistor 11 is, the shorter the length flowing in the resistor 11 is and the higher the conductivity between the two electrodes 12, 13 is, resulting in increased current quantity. This current is compared with the set value of a reference value generator 17 in a comparator 16, by which a flux feeder 18 is operated, whereby the depth of the slag bath 5 is controlled to a target value. The voltage and current ratio between the electrodes 12, 13 is compared with a standard ratio, whereby the travelling around the torch is controlled.