Pitting and stress corrosion cracking resistance of friction stir welded AA5083

摘要

The corrosion behaviour of friction stir welded (FSW) joints of AA 5083 has been compared to that of MIG welded joints. Pitting and stress corrosion cracking (SCC) resistance in 3.5% NaCl + 0.3 g/l H{sub}2O{sub}2 and in EXCO (4 M KCl + 0.5 M KNO{sub}3 + 0.1 M HNO{sub}3) solutions has been determined at 25℃. SCC susceptibility was evaluated by slow strain rate tests (SSRT), at a strain rate of 1×10{sup}(-6) s{sup}(-1). Welds obtained by FSW technique showed a higher corrosion resistance in EXCO solution and a lower pitting tendency than the base alloy. Electrochemical measurements (corrosion potential measurements, polarization curves recording) evidenced that FSW weld was cathodic to base alloy. FSW joints were not susceptible to SCC in both test solutions, whereas MIG joints cracked in both solutions.