UCSB Science Line
Sponge Spicules Nerve Cells Galaxy Abalone Shell Nickel Succinate X-ray Lens Lupine
UCSB Science Line
Home
How it Works
Ask a Question
Search Topics
Webcasts
Our Scientists
Science Links
Contact Information
Does saltwater affect the production of rust?
Answer 1:

Yes, very much. People who live near the ocean know this.
The reason is that the process of rusting involves electrons moving around, and electrons move more easily in salt-water than they do in clean water.A simple test of this is to see how easily current flows in clean water it does not), and then add salt to the water (when current does flow easily).

Answer 2:

Water is the enabler of fast oxidation of iron so freshwater will also cause rust. However, salt water is a very good conductor (lots of dissociated ions) and so there are a number of electrolysis reactions that tremendously accelerate corrosion in salt water.
For example if you have iron in contact with salt water and also in contact with another metal such as aluminum (also in contact with the water) you effectively get a battery which drives very fast corrosion processes.
This effect can be reversed by using a metal (like zinc) which causes the current to be reversed and in effect the zinc corrodes rapidly, protecting the iron. This is the principle of a 'Cal-rod' which is used to slow the rusting of hot water tanks (almost all of which are cast iron).
There is a lot of information on corrosion on the web...


Click Here to return to the search form.

University of California, Santa Barbara Materials Research Laboratory National Science Foundation
This program is co-sponsored by the National Science Foundation and UCSB School-University Partnerships
Copyright © 2015 The Regents of the University of California,
All Rights Reserved.
UCSB Terms of Use