Home /
T.O.C.
FAQs
 
Good
Books
Ref.
Libr.
Advertise
Here
Help
Wanted
Current
Q&A's
Search 🔍
the Site

World's #1 finishing resource since 1989
No login needed: Chime right in

topic 1388

FLASH RUST ON ONE SIDED ZINC COATED STRIP



1998

We are producing electroplated zinc steel sheet in a continuous electroplating line from a sulphate bath (pH 1.5). Single and double sided zinc coated sheet is manufactured. An acid rinse(1.5 pH length of rinse section-approx 50 meter) is applied after coating in order to remove losely adherent particles and to prevent the formation of flash rust on the non-coated side(steel side) of single sided material. A water rinse (pH 6-7) is finally performed before the strip is dried and oiled with a rust preventive oil.

We would like to change to a total water rinse system. What is the best way to prevent the formation of flash rust on the steel side in a total water rinse system(safe pH range, addition of an inhibitor,etc.)?

Your help is deeply appreciated.

Koos Greyling

Koos Greyling
Scientist: Process and surface Science - Iscor


1997

Addition of inhibitors to rinse water is the best way (cheap, convenient, efficient, no by-effect to the subsequent treatments, etc.) to prevent flash rust on steels. There are numerous commercial inhibitors available for your needs. You may try to add 1-5% sodium benzoate or sodium dichromate to the rinse water. Do a few experiments in your lab first to determine the optimum concentration. I believe both are able to provide prevention of steels from flash rust. However, sodium benzoate application is limited in the chloride-containing water, while sodium chromate is restricted for environmental protection.

Ling Hao
- Grand Rapids, Michigan

none
finishing.com is made possible by ...
this text gets replaced with bannerText
spacer gets replaced with bannerImages

Q, A, or Comment on THIS thread SEARCH for Threads about ... My Topic Not Found: Start NEW Thread

Disclaimer: It's not possible to fully diagnose a finishing problem or the hazards of an operation via these pages. All information presented is for general reference and does not represent a professional opinion nor the policy of an author's employer. The internet is largely anonymous & unvetted; some names may be fictitious and some recommendations might be harmful.

If you are seeking a product or service related to metal finishing, please check these Directories:

 
Jobshops
Capital
Equipment
Chemicals &
Consumables
Consult'g, Train'g
& Software


About/Contact    -    Privacy Policy    -    ©1995-2021 finishing.com, Pine Beach, New Jersey, USA