METHOD FOR ELECTRON-BEAM WELDING OF MONOCRYSTALLYNE PIPES FROM REFRACTORY METALS AND ALLOYS Russian patent published in 1996 - IPC

FIELD: manufacture of welded tubes from single crystals, particular, for units of thermal emission converters. SUBSTANCE: monocrystalline pipes from refractory metal and alloys prior to electron-beam welding are joined to each other with application of axial and radial forces and joint is oriented crystallographically. Passivation is accomplished with balancing of heat removal in zone of crystallization and heating of joint with defocussed beam. Welding is conducted under the conditions of welding bath existence for 0.05-0.2 s. After welding, trueing is effected by increasing radial force and simultaneous rotation of pipes and maintaining the temperature of pipe heating not below the plastic flow of material under the applied radial force. EFFECT: increased yield by joint monocrystallinity up to 97-100%. 1 dwg