Change search
ReferencesLink to record
Permanent link

Direct link
Atmospheric corrosion effects of HNO3—Influence of concentration and air velocity on laboratory-exposed copper
Corrosion and Metals Research Institute (KIMAB).
KTH, School of Chemical Science and Engineering (CHE), Chemistry, Corrosion Science.ORCID iD: 0000-0002-9453-1333
2006 (English)In: Atmospheric Environment, ISSN 1352-2310, Vol. 40, no 20, 3631-3639 p.Article in journal (Refereed) Published
Abstract [en]

 `A recently developed experimental set-up has been used to explore the atmospheric corrosion effects of nitric acid (HNO3) on copper, in particular the influence of concentration and air velocity. Characterization and quantification of the corrosion products on exposed samples were performed with Fourier transform infrared (FT-IR) microspectrocscopy, ion chromatography, X-ray diffraction (XRD), micro-balance and microscopy. At low air velocity (0.03 cm s(-1)) HNO3 deposition and weight gain of copper increased linearly with concentration Lip to 400 mu g m(-3) or 156 ppb. The influence of air velocity on corrosion of copper was tested within the range of 0.03-35.4 cm s(-1). Although the air velocity in this study was significantly lower than typical outdoor wind values, a high HNO3 concentration of the air velocity of 35.4 cm s(-1) resulted in a relatively high deposition velocity (V-d) of 0.9 cm s(-1) on the metal surface and 1.2 cm s(-1) on an ideal absorbent, which would imply a limiting deposition velocity on the copper surface (V-d,V-surf) of 3.6 cm s(-1). Results obtained in this study emphasize the importance for future research on the corrosion effects of HNO3 on materials as very little has so far been done in this field.

Place, publisher, year, edition, pages
2006. Vol. 40, no 20, 3631-3639 p.
Keyword [en]
nitric acid, deposition rate, mass transport, materials degradation, gerhardtite
National Category
Engineering and Technology
URN: urn:nbn:se:kth:diva-6442DOI: 10.1016/j.atmosenv.2006.03.026ISI: 000238588600001ScopusID: 2-s2.0-33646826683OAI: diva2:11157
QC 20100831Available from: 2006-11-29 Created: 2006-11-29 Last updated: 2010-08-31Bibliographically approved
In thesis
1. HNO3-Induced Atmospheric Corrosion of Copper, Zinc and Carbon Steel
Open this publication in new window or tab >>HNO3-Induced Atmospheric Corrosion of Copper, Zinc and Carbon Steel
2006 (English)Doctoral thesis, comprehensive summary (Other scientific)
Abstract [en]

The role of nitric acid (HNO3) on the atmospheric corrosion of metals has so far received little or no attention. However, the last decades of decreasing sulphur dioxide (SO2) levels and unchanged HNO3 levels in many industrialized countries have resulted in an increased interest in possible HNO3-induced atmospheric corrosion effects. In this study a new method was developed for studying the corrosion effects of HNO3 on metals at well-defined laboratory exposure conditions. The method has enabled studies to be performed on the influence of individual exposure parameters, namely HNO3-concentration, air velocity, temperature and relative humidity, as well as comparisons with newly generated field exposure data.

The corrosion rate and deposition rate of HNO3 on copper was shown to follow a linear increase with HNO3 concentration. The deposition velocity (Vd) of HNO3 increased up to an air velocity of 11.8 cm s-1. Only at a higher air velocity (35.4 cm s-1) the Vd on copper was lower than the Vd on an ideal absorbent, implying the Vd of HNO3 at lower air velocities to be mass-transport limited.

Within the investigated temperature range of 15 to 35 ºC only a minor decrease in the HNO3-induced copper corrosion rate could be observed. The effect of relative humidity (RH) was more evident. Already at 20 % RH a significant corrosion rate could be measured and at 65 % RH the Vd of HNO3 on copper, zinc and carbon steel reached maximum and nearly ideal absorption conditions.

During identical exposure conditions in HNO3-containing atmosphere, the corrosion rate of carbon steel was nearly three times higher than that of copper and zinc. The HNO3-induced corrosion effect of copper, zinc and steel turned out to be significantly higher than that induced by SO2 alone or in combination with either NO2 or O3. This is mainly attributed to the much higher water solubility and reactivity of HNO3 compared to SO2, NO2 and O3. Relative to SO2, zinc exhibits the highest sensitivity to HNO3, followed by copper, and carbon steel with the lowest sensitivity.

Extrapolation of laboratory data to an assumed average outdoor wind velocity of 3.6 m s-1 enabled a good comparison with field data. Despite the fact that ambient SO2 levels are still much higher than HNO3 levels, the results show that HNO3 plays a significant role for the atmospheric corrosion of copper and zinc, but not for carbon steel. The results generated within this doctoral study emphasize the importance of further research on the influence of HNO3 on degradation of other materials, e.g. stone and glass, as well as of other metals.

Place, publisher, year, edition, pages
Stockholm: Kemi, 2006
Nitric acid, deposition velocity, mass transport, air velocity, relative humidity
National Category
Chemical Sciences
urn:nbn:se:kth:diva-4194 (URN)91-7178-483-7 (ISBN)
Public defence
2006-12-08, Sal F3, KTH, Lindstedtsvägen 26, Stockholm, 10:00
Available from: 2006-11-29 Created: 2006-11-29

Open Access in DiVA

No full text

Other links

Publisher's full textScopus

Search in DiVA

By author/editor
Samie, FaridTidblad, JohanLeygraf, Christofer
By organisation
Corrosion Science
In the same journal
Atmospheric Environment
Engineering and Technology

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 69 hits
ReferencesLink to record
Permanent link

Direct link