Rolled or extruded aluminium Al-Mn alloy products with improved corrosion resistance

摘要

The invention concerns a rolled or extructed product, in particular a tube, made of an alloy composition (expressed in wt. %) comprising: Si0.30; Fe 0.20-0.05; Cu0.05; Mn 0.5-1.2; Mg0.05; Zn0.50; Cr 0.10-0.30; Ti0.05; Zr0.05; the balance consisting of aluminium and unavoidable impurities. The invention also concerns a method for making extruded tubes of said composition comprising casting a billet, optionally homogenizing it, extruding a tube, drawing said tube in one or several passes and continuous annealing at a temperature ranging between 350 and 500° C. with a temperature increase of less than 10 seconds. The inventive products are designed for pipes and heat exchangers for motor vehicles, and exhibit good corrosion resistance.