METHOD FOR CONTACT BUTT WELDING OF RAILS Russian patent published in 2021 - IPC B23K11/04 B23K101/26 E01B29/42 

FIELD: railway transport.

SUBSTANCE: invention can be used in the manufacture of resistance butt welding of long rails and continuous welded strings for the tracks of railway, urban and industrial transport. After preliminary machining of the welded ends of the rails and their heating, upsetting is carried out for 160–260 s, holding, followed by passing an alternating electric current through the welded joint with 4–6 pulses of 2–6 s duration at intervals of 10–30 s at a current density of 2– 40 A/mm². During periods of heating of the ends being welded and upsetting, argon is supplied to the welding zone with a pressure of 1.05–1.5 MPa, a flow rate of 0.06–0.20 m³/s and an outflow rate of up to 30 m/s.

EFFECT: invention provides the required physical and mechanical properties of the welded joint by reducing the level of oxide non-metallic inclusions and eliminating microcracks in the weld.

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