METHOD FOR DESENSITIZATIO TO INTERCRYSTALLINE CORROSION OF 2000 AND 6000 SERIES ALUMINUM ALLOYS AND ALUMINUM ALLOY OBTAINED BY THIS METHOD

摘要

PURPOSE: To improve the resistivity to the intercrystalline corrosion of 2000 and 6000 series Al alloys by executing the heat treatment of these Al alloys at a specific low temp. of a soln. heat treating temp. ;CONSTITUTION: In the case of the 2000 series Al alloys used in the states of T3, T3XX, T4, T8, T8XX among the members consisting of the 2000 series Al alloys contg. Cu or Cu and Mg at a specific ratio and the 6000 series Al alloys contg. a specific ratio of Si and Mg or Si, Mg and Cu, the Al alloys are subjected to a soln. heat treatment at a temp. lower by 10 to 30°C than the ordinary soln. heat treating temp. and the 6000 system Al alloys used in the state of T6, T6XX is subjected to the soln. heat treatment at a temp. lower by 10 to 100°C than the ordinary soln. heat treating temp. The Al alloys which are higher by at least 0.7 MS/m in the surface electrical conductivity of the Al alloys and are higher by at least 3J/g in the energy accompanying the eutectic melting peak determined by a differential enthalpy analysis temp. curve and has the excellent resistivity to the intercrystalline corrosion are obtd.;COPYRIGHT: (C)1995,JPO