METHOD FOR CONTROLLING PROCESS OF HIGH-FREQUENCY WELDING OF PIPE BILLET Russian patent published in 2021 - IPC B23K13/02 B23K101/06 B21C37/08 

FIELD: electric-welded steel pipes production.

SUBSTANCE: invention can be used in the production of electric-welded steel pipes by high-frequency welding. The moments of occurrence of welding bridges are determined by isolating a differentiated signal of changing the voltage frequency of the welding generator. After determining the number of welding bridges formed during the formation of a section of a welded joint of a given length, the obtained value is compared with the specified minimum and maximum permissible values. According to the comparison results, the heating of the edges of the welded pipe billet is reduced or increased. The number and length of successively formed sections of the welded joint, the boundaries of which correspond to the moments of occurrence of adjacent welding bridges, are determined. The proportion of the mentioned segments, the length of which is greater or less than the maximum specified value, of the total number of segments, sequentially formed during the formation of the section of the welded joint, is determined. The obtained values of the indicators are compared with the specified maximum permissible values, and according to the results of the comparison, the heating of the edges of the welded pipe billet is reduced or increased.

EFFECT: reduction of the content of non-metallic inclusions in the welded joint.

2 cl