METHOD TO PRODUCE AXISYMMETRIC FORGINGS OF COVER TYPE WITH DIAMETER UP TO 200 MM FROM HIGH-STRENGTH ALUMINIUM ALLOYS AL - ZN - MG - CU, ALLOYED BY SCANDIUM AND ZIRCONIUM Russian patent published in 2014 - IPC C22F1/53 B21D22/00 C22C21/10 

FIELD: metallurgy.

SUBSTANCE: method to produce axisymmetric forgings of a cover type with a diameter of up to 200 mm from high-strength aluminium alloys Al-Zn-Mg-Cu, alloyed with scandium and zirconium, includes preparation of aluminium melt, containing scandium and zirconium, its reheating to 765-780°C, casting of round bars of small diameter at 710-740°C, their homogenisation at 400-440°C for 4-10 hours, stamping at 380-440°C, tempering from temperature 465-480°C with even cooling of the entire surface of forgings with speed providing for preservation of fully non-crystallised structure of the forging after tempering, and artificial ageing.

EFFECT: forgings have lower level of residual tempering stresses, which provides for stability of geometric parameters of parts due to elimination of ovalisation when turning forgings into thin-walled parts.

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