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Long-Term Atmospheric Corrosion of Hot-Dip Galvanized Steel and Zn-Al Coated Steel

Thursday, 4 October 2018: 14:00
Universal 1 (Expo Center)
D. Thierry (French Corrosion Institute) and D. Persson (Swerea Kimab)
Hot dip galvanized steel and zinc alloyed coated steel such as ZnAl are widely used in the building industry. However, despite large efforts made to study the corrosion products formed on zinc under atmospheric weathering conditions (see for instance reference 1 and 2), very few data exist on HDG and zinc alloyed coated steel [5].

This work is a part of a larger research program were steel with different zinc coatings are exposed on a worldwide basis on well characterized exposure sites in Europe, Asia and North America, see Table 1.

Corrosion rates of hot dip galvanized steel and zinc aluminum coated steel (e.g. Zn5%Al and Zn 55% Al) were determined after 1, 2, 4 and 6 years of exposure under different climatic conditions.

The formation and development of corrosion products was followed by detailed analysis of samples exposed 0.5, 1, 2, 4 and 6 years using XRD, FTIR-spectroscopy and SEM-EDS. The data are discussed in view of current knowledge in the atmospheric corrosion of zinc, HDG and Zn-Al coated steel materials [1-6]

Table 1. Test sites in the exposure program

Code

Name

Country

Distance to Sea(m)

A

Brest

France

<5

B

Bohus-Malmön (I)

Sweden

<5

C

Bohus-Malmön (II)

Sweden

300

D

Ijmuiden

Netherlands

2600

E

Cadiz

Spain

750

F

Jiangjin

China

̴900 km

G

Ostrawa

Czech Republic

̴500 km

H

Dubai

UAE

2000

I

Daytona Beach

USA

100

J

Quindao

China

10

K

Wanning

China

100

L

Bangkok

Thailand

35 km

M

Sattahip

Thailand

10

N

Singapore

SIngapore

10

References

1-I. Odnevall, C. Leygraf, Corros. Sci. 34 (1993) 1213–1229.

2- I. Odnevall, C. Leygraf, Corros. Sci. 36 (1994) 1551–1567.

3- N. Le Bozec, D. Thierry, M. Rohwerder, Dan Persson, G. Luckeneder and L. Luxem, Effect of CO2 on the atmospheric corrosion of ZnMgAl coated steel, Corrosion Science, 74, pp 379-386, 2013

4- E. Diller, B. Lescop, S. Rioual, G Nguyen, D. Thierry and B. Rouvello, Initial formation of corrosion products on pure zinc and MgZn2 examined by XPS: Corrosion Science 79, pp 83-88, 2014.

5- D. Persson, N. Le Bozec, T. Prosek, D. Thierry, G. Luckenader , Corrosion Science Vol 90, pp 276-283, 2015.

6- D. Persson, D. Thierry, N. Le Bozec: Corrosion products formation on Zn55Al upon exposure in marine atmosphere, Corrosion Science, 720, 2011.