Operating the generator with 18 % Mn 5 % Cr Retaining Ring 1

[powering2002]

Dear all,
Our Power Plant (Combined Cycle Power Plant) was built in 1990's. The material composition of the generator retaining ring is 18 % Mn 5 % Cr. We also have been informed, that several 18 % Mn 5 % Cr Retaining ring failure were cauded by stress corossion cracking. My question is, is it safe for us to operate these generators?

 

[MikeHalloran]

You can't eliminate the stress.

Can you protect the part from corrosion?

What corrosive substances were present at the reported failures?
Are they present at your location?



Mike Halloran
Pembroke Pines, FL, USA

 

[powering2002]

Dear Mike, there is no corrosion in our retaining ring in our power plant....Thanks...

 

[hooverdale]

Is this a GE generator? See this link.

http://site.ge-energy.com/prod_serv/products/tech_docs/en/downloads/ger3930.pdf

 

[rmw]

Several questions:

Is this an air cooled generator, or hydrogen cooled (or otherwise)?

Are you located in a marine environment or an evironment where chlorides may be present in the air?

Does the plant operate continuously or is it off line for any amount of appreciable time?

The answers to the above questions will determine any "tips" I might have to offer.

rmw

 

[powering2002]

Dear hooverdale, we don't use GE Generator. We use Toshiba Generator
Dear rmw, Our Toshiba Generators are:
1. They are hydrogen cooled generator
2. Our Power Plant is located near the sea. But, we haven't check the chloride content of the ambient air.
3. Our Steam plant operate continuously. Used as base load.
4. It consists of 4 Generators. 2 x 100 MW and 2 x 200 MW.
Thanks a lot