MATERIALS AND COATING JOINING METHOD Russian patent published in 2007 - IPC B23K31/02 B23K33/00 B23K101/06 

FIELD: welding processes and equipment, namely methods for protecting inner surface of welded seam of parts having inner multi-layer protection coating with fragile layers against corrosion action of aggressive medium.

SUBSTANCE: method comprises steps of forming beads 3 on portions of surface of parts 1, 2 without coating; assembling parts according to beads and welding with use of single heating source; applying multi-layer coating; before applying coating forming protrusions 4 on shaped beads and forming cavity 7 under them; at assembling providing touching along surfaces 8 of said protrusions for further welding; forming portion of bead surface under protrusions without inner layer of coating; filling part of cavity between protrusions and end of inner layer of coating with material of outer layer or layers 6; providing thickness of protrusion no less than total thickness of inner and outer layers of coating; using as outer layer or layers of coating material thermally softening at high temperatures during welding process.

EFFECT: improved operational reliability, enhanced protection of parts having inner protection coating with fragile layers.

4 dwg