Measuring Corrosion

P

phatch

Joined
Oct 3, 1998
Messages
2,835
Found this in the local paper about some research of metals corrosion, particularly steel, stainless steel and aluminum.
http://deseretnews.com/dn/view/0,1249,230011618,00.html?

The summary is they use wheels of the materials with various protective coatings and measure the rate of electron flow out of the metal that occurs as the metal corrodes.

Something similar to corn oil is getting high marks.

Phil
 
This paper deals with surfactants. These are agents which lower surface tension; in general, they are molecules which are attracted to lipids (oils) at one end, and attracted to water at the other end. More precisely, lipophilic at one end, hydrophilic at the other. If this sounds unfamiliar, it is just the terminology. Things like soaps and detergents are surfactants.

The problem with putting oil on a metal to prevent corrosion is that the oil will tend to cover up any water present on the metal. Things such as surfactants are added to oil so that the oil will displace the water, and thus protect the surface of the metal. It should come as no surprise that WD-40 is mineral oil and a surfactant, or that WD stands for Water Displacing.

There is a lot more to corrosion than what happens to rotating discs. Galvanic current, crevices which lower oxygen levels, the concentration of halogen ions, especially Cl-, bacterial growth, CO2 partial pressure, temperature and humidity are just a few.

For a good post which has some info about sea water corrosion and the materials resistant to it, (some of which are used in the knife industry)see: http://www.corrosionsource.com/discuss2/ubb/Forum4/HTML/000140.html

This is from a corrosion discussion group which has posts from around the world. Well worth perusing.

Hope this helps, Walt

[This message has been edited by Walt Welch (edited 11-27-2000).]
 
You must log in or register to reply here.
Back
Top