METHOD OF FLASH BUTT WELDING OF METAL PIPES Russian patent published in 2025 - IPC B23K11/04 B23K101/06 

FIELD: performing operations.

SUBSTANCE: invention relates to contact flash butt welding of metal pipes. Change in physical state is monitored during melting of metal pipes during welding. Required amount of heat required to achieve the specified thermal state of the welded ends of the pipes is preliminary calculated, for which the required values of temperature of the ends of the welded pipes, the gradient of the temperature field before forcing and the value of upsetting for obtaining the welded joint are determined. During welding, constant specific instantaneous power released in spark gap between pipes is maintained by changing rate of fusion. During the reflow process, the current temperature, the current coefficient of the temperature field gradient and the amount of heat received by the ends are measured to determine the current amount of heat energy released in the spark gap. If, as a result of comparing current values of parameters, the amount of heat accumulated by the ends and the gradient coefficient is less than the required value, then the rate of melting is increased and the process of melting is continued until the current temperature and amount of thermal energy match with their required values, after that, forcing mode and subsequent upsetting is implemented taking into account actually obtained coefficient of temperature field gradient.

EFFECT: control of the thermal state of the welded pipe ends, carried out during the welding process, ensures the production of a high-quality weld.

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