Jagdeep
Galvanic corrosion is the corrosion damage caused when two dissimilar
materials are in contact. It occurs when two (or more) dissimilar metals are
brought into electrical contact under water.
Metals have different electrical properties. Metals that are "more noble"
will corrode quicker than the "less noble" metal. When a galvanic couple
forms, one of the metals in the couple becomes the anode and corrodes faster
than it would all by itself, while the other becomes the cathode and
corrodes slower than it would alone. In your case the noble to less noble
metals are in the ffg order : copper, brass and then SS. You haven't
specified which metal is corroding faster, but according to the EMF table,
the SS would be the main victim of this coupling
Ahmed Vawda
Process Engineer
Al Khaleej Sugar - Dubai
-----Original Message-----
From: punnu_h2003 [mailto:jsingh11@rediffmail.com]
Sent: Monday, June 02, 2003 8:11 AM
To: PipingDesign@yahoogroups.com
Subject: [PipingDesign] Galvanic corrosion
Thanks for some stuff on the subject. But I am specifically looking for the possible reason of corrosion when SS tube and a Copper tube have a Brass coupling to join them. What could have triggered the Galvanic Corrosion.
-----Original question-------
My question relates to the Compatibility of distinct materials when
used in assembly. To be specific, there is a case where a SS tube is
joined to a Copper tube wit a brass coupling. At the joint, corrosion
has set in. Why and what is the cause? What metal properties of these
materials are conflicting causing corrosion.? What is actually a
Galvanic corrosion?Thanks. I hope to get good and informative
response.
Jagdeep
Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ Received on Mon Jun 09 02:24:00 2003
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