METHOD OF RESISTANCE FUSION WELDING OF STEEL RAILS Russian patent published in 2007 - IPC B23K11/04 B23K101/26 

FIELD: mechanical engineering; welding.

SUBSTANCE: method includes flash-off and upsetting for push-up allowance with determination of upsetting force. At upsetting, specific compressive force is calculated as quotient obtained at division of compressive force on area of cross section of rail by which heat input at flash -off is judged. Calculated value of specific compressive force is compared with threshold value of specific compressive force found experimentally. If these calculated and threshold values of specific compressive forces are equal, welding cycle is completed. If calculated value of specific compressive force exceeds threshold value of specific compressive force, difference between these values is found which is used as quantity index of electric energy required for adding to welded joint. Product of said difference by constant C lying within 0.7 and 0.85 kW.h.sq mm/kg, depending on grade of steel in rails, is calculated. Voltage is applied to weld joint and amount of additional energy is checked. When said energy reaches value determined by product of difference of compressive forces by constant C, voltage is switched off, and welding cycle is completed.

EFFECT: improved quality of weld joint owing to stabilization of heating of parts.

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