Properties of Semi-Finished Products and Welded Joints of An Aluminum Alloy V92Zr After Prolonged Low-Temperature Heating

The high-strength aluminum alloy V92Zr system Al-Zn-Mg is self-quenched alloy. The major alloying elements are 4.2 wt % Mg, 3.2 wt % Zn, 0.6 wt % Mn, and 0.15 wt % Zr. The most acceptable filler wires to weld this alloy are V92W, alloys AMg6, AMg4Zr and No.11 (Al-Zn-Mg). This alloy can be used in the aircraft production.

Prolonged heating at 50-70°C can lead to substantial structural changes in precipitation hardening of aluminum alloys due to the transition from zone to phase aging. Zone aging of Al-Zn-Mg alloys, particularly the weld seams, with repeated heating at 50-70°C substantially increases the strength and lowers the elongation, reduction in cross-sectional area, toughness, resistance to stress corrosion, and increases susceptibility to cracking. Heating at temperatures even below the phase aging temperature changes the properties considerably.

This article deals with the effect of prolonged low-temperature heating on the mechanical properties, sensitivity to cracks in impact bending, and corrosion resistance of semi-finished products and weldments of aluminum alloys V92Zr after solution treatment and aging at the room and elevated temperatures.