METHOD OF MAKING TUBES FROM Al-Zn-Mg-Cu-SYSTEM-BASED SUPERHARD ALUMINIUM ALLOYS Russian patent published in 2013 - IPC B21B23/00 

FIELD: process engineering.

SUBSTANCE: invention relates to metallurgy, particularly, to production of 90-150 mm-dia tubes from superhard Al-Zn-Mg-Cu-system-based aluminium alloys to be used in aerospace engineering, oil-and-gas industry, and nuclear engineering. Method of production of 90-150 mm-dia tubes from superhard Al-Zn-Mg-Cu-system-based aluminium alloys comprises semicontinuous casting with modification of structure to grain size equal to dendritic parameter and stepwise casting blending. Note here that second stage temperature is cooled to that of production of 90-150 mm-dia tubes from superhard Al-Zn-Mg-Cu-system-based aluminium alloys to room temperature. Then machining for forming is performed followed by tube forming. Tubes are annealed at temperature of minimum stability of solid solution and held for 1-2 hours and cooled to 150°C. Note tubes are subjected to cold rolling, tempering, straightened and artificial ageing.

EFFECT: better mechanical properties, longer life.

6 tbl, 1 ex