Liquid die forging and rolling compound formation method for 7050 aluminum alloy irregular-section large ring piece

Abstract

The invention relates to a liquid die forging and rolling compound formation method for a 7050 aluminum alloy irregular-section large ring piece. The method comprises the following steps of: 1) smelting; 2) performing liquid die forging, namely fixing a liquid die forging mold on an indirect extrusion casting machine, pouring an alloy solution into the die forging mold at the pouring temperature of between 700 and 730 DEG C, pressurizing at the speed of 35 to 40 mm / s, filling for 1 to 6 seconds at the specific pressure of 160 to 200 MPa, keeping the pressure for 35 to 45 seconds, and thus obtaining a similarly final section ring blank; 3) homogenizing, namely cooling the similarly final section ring blank to the temperature of 430 DEG C, keeping the temperature for 18 hours, heating to the temperature of 467 DEG C, and keeping the temperature for 12 hours; 4) performing afterheat isothermal rolling, namely cooling the homogenized similarly final section ring blank to the temperature of between 430 and 440 DEG C, and performing afterheat isothermal rolling on a radial shaft compound ring rolling machine; 5) performing thermal treatment, namely performing keeping the ring blank obtained through afterheat isothermal rolling at the temperature of 470 DEG C for 40 min, then heating to the temperature of 485 DEG C and keeping the temperature for 40 min, quenching in cold water and keeping the temperature of 135 DEG C for 12 hours, heating to the temperature of 170 DEG C and keeping the temperature for 2 hours, and cooling to the temperature of 135 DEG C and keeping the temperature for 12 hours; and 6) finishing.

Description

technical field [0001] The invention relates to a short-process processing and forming method for large-diameter metal rings with complex cross-sections, in particular to a liquid die forging and rolling composite forming method for large-scale rings with different cross-sections of 7050 aluminum alloy. Background technique [0002] With the rapid development of my country's aerospace industry, high-thrust launch vehicles are in urgent need of large-scale complex-section aluminum alloy rings with a diameter of more than 5 meters. The so-called complex cross-section ring refers to a metal ring with a large difference in the cross-sectional area of ​​the ring in the axial direction, a large change in the shape and size of the cross-section of the ring, and a relatively complex shape of the inner surface and the outer surface. An important part of the success of a rocket project is the key connector of the launch vehicle. The special use environment puts forward almost strict ...

AI Technical Summary

Problems solved by technology

[0004]1) The process is lengthy, with many procedures and low production efficiency;

[0005]2) The rolled and expanded ring blank needs to be prepared by punching, and the final cross-sectional shape needs to be guaranteed by cutting excess dressing, so the material utilization rate is low;

[0006]3) The machining process cuts off the metal flow line, resulting in a decrease in the comprehensive mechanical properties of the ring;

[0007]4) The preparation process requires repeated heating, resulting in coarse grains, severe surface oxidation, and large energy consumption

[0008]The Chinese patent with the publication number CN 101817134A discloses a method for short-flow casting-rolling composite forming of metal rings. Although the method satisfies the beneficial effect of short production process and saving energy, materials and manpower to a certain extent, the method adopts centrifugal casting ring billet, which cannot meet the processing requirements of complex cross-section rings, and the comprehensive mechanical properties of the metal rings obtained are The performance is still not up to the use requirements of launch vehicles