METHOD OF SECURING TUBES IN TUBE GRATE OPENINGS Russian patent published in 1994 - IPC

FIELD: plastic working of metals. SUBSTANCE: method involves bevelling opening of tube grate at side opposite to explosive charge introduction side, with length of explosive charge being in excess of tube grate thickness; bevelling opening 2 with diameter d_o of tube grate 3, with angle L of bevel 5 being equal to 5.5-7 deg, maximum diameter of (1.03-1.10) d_o and face 6 having rounded radius R at least equal to 1/2 h; mounting tube 1 into opening 2; introducing explosive charge 8 into tube 1 at untreated side of it, with explosive charge length being in excess of tube grate thickness for a value calculated in accordance with predetermined dependence exploding detonating cord 9, which initiates explosive charge 8. Tube 1 is expanded in opening 2 as a result of action of pressure developed during explosion. Bevelled portion in opening 2 and portion of explosive charge 8 extending beyond opening end prevent formation of space between tube 1 and opening 2 of tube grate and consequently occurrence of crevice corrosion is eliminated. EFFECT: enhanced reliability of obtained connection and elimination of occurrence of crevice corrosion. 1 dwg