METHOD OF WELDED JOINT OF ANNULAR SINGLE-THICKNESS BUTT JOINTS OF BIMETALLIC PIPES AND/OR CONNECTING PARTS OF PIPELINES Russian patent published in 2024 - IPC B23K33/00 B23K9/14 F16L13/02 B21C37/08 

FIELD: various technological processes.

SUBSTANCE: present invention relates to methods of electric arc welding of bimetallic butt joints of parts of pipelines with internal corrosion-resistant cladding layer, which are used for movement of aggressive media. After processing of connected ends of bimetallic pipes they are fixed coaxially and welding is performed by successive passes with formation of multilayer connection. Parameters of layers of the obtained weld in multipass welding are regulated. Welding of root layer of seam, filling layers and facing layer of seam is performed by coated electrodes with chemical composition of rod, wt.%: Ni not less than 60.0, Cr from 13.0 to 17.0, Fe to 10.0, Mn from 5.0 to 10.5, Nb from 1.0 to 3.5, Si up to 1.0, Ti up to 1.0, Cu up to 0.5, C up to 0.1.

EFFECT: production of welded joint of annular single-thickness butt joints of bimetallic pipes and/or connecting parts of pipelines in field conditions with preservation of quality of such joint and increase of corrosion resistance and mechanical strength.

18 cl, 21 dwg, 5 tbl