Corrosion behaviour of AZ31 magnesium during the initial six exposure periods in a tropical marine atmosphere is investigated. The results reveal that corrosion process of magnesium is dominated by pitting corrosion which consists of initiation of new pits, propagation of small scale pits and coalescence of neighbouring pits. There exists a critical depth above which the pits cease to grow down, resulting in the fluctuation of the mean pit depth. Different exposure conditions are found to be crucial for the different pit characters. Pits on the skyward surface are in deep-hole shape, while the groundward surface is covered with shallow dish pits.
MordikeBL and EbertT: ‘Magnesium: properties—applications—potential’Mater. Sci. Eng. A2001A30237–45.
2.
FriedrichH and SchumannS: ‘Research for a ‘new age of magnesium’ in the automotive industry’, J. Mater. Process. Technol.2001117276–281.
3.
ZhouWQShanDYHanEH and KeW: ‘Influence of NaCl deposition on atmospheric corrosion behavior of AZ91 magnesium alloy’Trans. Nonferrous Met. Soc. China201020s670–s673.
4.
ZhouWQShanDYHanEH and KeW: ‘Initial corrosion behavior of AZ91 magnesium alloy in simulating acid rain under wet-dry cyclic condition’Trans. Nonferrous Met. Soc. China200818s334–s338.
5.
ZhangTChenCMShaoYWMengGZWangF.HLiXG and DongCF: ‘Corrosion of pure magnesium under thin electrolyte layers’Electrochim. Acta2008537921–7931.
6.
MeiraGRAndradeCAlonsoCPadaratzIJ and BorbaJC: ‘Modelling sea-salt transport and deposition in marine atmosphere zone–A tool for corrosion studies’Corros. Sci.2008502724–2731.
7.
JönssonMPerssonD and LeygrafC: ‘Atmospheric corrosion of field-exposed magnesium alloy AZ91D’Corros. Sci.2008501406–1413.
8.
YangLJLiYFWeiYHHouLFLiYG and TianY: ‘Atmospheric corrosion of field-exposed AZ91D Mg alloys in a polluted environment’Corros. Sci.2010522188–2196.
9.
FeliuSPardoAMerinoMCCoyAEViejoF and ArrabalR: ‘Correlation between the surface chemistry and the atmospheric corrosion of AZ31, AZ80 and AZ91D magnesium alloys’Appl. Surf. Sci.20092554102–4108.
10.
FuenteDHuertaE and MorcilloM: ‘Studies of long-term weathering of aluminium in the atmosphere’Corros. Sci.2007493134–3138.
11.
AsamiK and HashimotoK: ‘Importance of initial surface film in the degradation of stainless steels by atmospheric exposure’Corros. Sci.2003452263–2283.
12.
JönssonMPerssonD and ThierryD: ‘Corrosion product formation during NaCl induced atmospheric corrosion of magnesium alloy AZ91D’Corros. Sci.2007491540–1558.
13.
LiYGWeiYHHouLF and HanPJ: ‘Atmospheric corrosion of AM60 Mg alloys in an industrial city environment’Corros. Sci.20126967–76.
14.
LiQXWangZYHanW and HanEH: ‘Characterization of the rust formed on weathering steel exposed to Qinghai salt lake atmosphere’Corros. Sci.200850365–371.
15.
FuenteDAzDISimancasJChicoB and MorcilloM: ‘Long-term atmospheric corrosion of mild steel’Corros. Sci.201153604–617.
16.
SunSZhengQLiD and WenJ: ‘Long-term atmospheric corrosion behaviour of aluminium alloys 2024 and 7075 in urban, coastal and industrial environments’Corros. Sci.200951719–727.
17.
CuiZYLiXGXiaoK and DongCF: ‘Atmospheric corrosion of field-exposed AZ31 magnesium in tropical marine environment’Corros. Sci.201376243–256.
18.
‘Corrosion of metals and alloys—classification of corrosivity of atmospheres’ISO 9223, ISOGevena, Switzerland1992.
19.
‘Standard guide for examination and evaluation of pitting corrosion’G46, ASTMPhiladelphia, PA, USA1994.
20.
ErnstP and NewmanRC: ‘Pit growth studies in stainless steel foils. I. Introduction and pit growth kinetics’Corros. Sci.200244927–941.
21.
YangYGZhangTShaoYWMengGZ and WangFH: ‘New understanding of the effect of hydrostatic pressure on the corrosion of Ni-Cr-Mo-V high strength steel’Corros. Sci.201373250–261.
22.
JönssonM and PerssonD: ‘The influence of the microstructure on the atmospheric corrosion behaviour of magnesium alloys AZ91D and AM50’Corros. Sci.2010521077–1085.
23.
SongGL and AtrensA: ‘Understanding magnesium corrosion—a framework for improved alloy performance’Adv. Eng. Mater.20035837–858.
24.
LanTTNThoaNTPNishimuraRTsujinoYYokoiM and MaedaY: ‘Atmospheric corrosion of carbon steel under field exposure in the southern part of Vietnam’Corros. Sci.200648179–192.
25.
MartinHJHorstemeyerMF and WangPT: ‘Comparison of corrosion pitting under immersion and salt-spray environments on an as-cast AE44 magnesium alloy’Corros. Sci.2010523624–3638.
26.
WaltonCAMartinHJHorstemeyerMF and WangPT: ‘Quantification of corrosion mechanisms under immersion and salt-spray environments on an extruded AZ31 magnesium alloy’Corros. Sci.201256194–208.
27.
MartinHJHorstemeyerMF and WangPT: ‘Structure–property quantification of corrosion pitting under immersion and salt-spray environments on an extruded AZ61 magnesium alloy’Corros. Sci.2011531348–1361.
