Effect of mechanical treatment on intergranular corrosion of 6064 alloy bars

4th International Conference Recent Trends in Structural Materials

Sláma, P.^1 ; Nacházel, J.^1

COMTES FHT A.s, Prmyslová 995, Dobany, Czech Republic^1

关键词: Artificial ageing;    Artificial aging;    Corrosion tests;    Corrosion types;    Mechanical processing;    Mechanical treatments;    Mechanical working;    Transgranular;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/179/1/012064/pdf
DOI  :  10.1088/1757-899X/179/1/012064

来源: IOP

【 摘 要 】

Aluminium Al-Mg-Si-type alloys (6xxx-series) exhibit good mechanical properties, formability, weldability and good corrosion resistance in various environments. They often find use in automotive industry and other applications. Some alloys, however, particularly those with higher copper levels, show increased susceptibility to intergranular corrosion. Intergranular corrosion (IGC) is typically related to the formation of microgalvanic cells between cathodic, more noble phases and depleted (precipitate-free) zones along grain boundaries. It is encountered mainly in AlMgSi alloys containing Cu, where it is thought to be related to the formation Q-phase precipitates (Al4Mg8Si7Cu2) along grain boundaries. The present paper describes the effects of mechanical working (extrusion, drawing and straightening) and artificial aging on intergranular corrosion in rods of the 6064 alloy. The resistance to intergranular corrosion was mapped using corrosion tests according to EN ISO 11846, method B. Corrosion tests showed dependence of corrosion type on mechanical processing of the material. Intergranular, pitting and transgranular corrosion was observed. Artificial ageing influenced mainly the depth of the corrosion.