finishing.com -- The Home Page of the Finishing Industry
A website for Serious Education, promoting Aloha,
& the most FUN smiley you can have in metal finishing

HomeFAQsBooksHelpWantedAdvertiseForum
(current
topics)
topic 6746

Discoloration on Nickel Parts after washing


(2000)

We are a large-volume manufacturer of terminals with nickel-plated parts.

A client is having trouble with discoloration of parts during washing. Their washing cycle involves an acid washing step with a solution containing phosphoric acid, an alkali washing step, and a step with a rust inhibitor. Each step has a rinse after it, and it is all concluded with a hot air drying process carried out at 185 degrees F.

An EDX of the discolored parts shows the presence of phosphorus in addition to nickel. The discoloration is usually a black or a dark tan/sepia color. The shape of the discolored spots suggests that they form while the droplets of solution are drying.

Is there anything that the client can do to alleviate this situation?

Mark Matsuno
- Cincinnati, Ohio


(2000)

Much better rinsing is required. This could be more rinse tanks, better water, more water or longer duration in the rinse cycle. Warmer rinse water will even help. James Watts
- Navarre, Florida



This public forum has 60,000 threads. If you have a question in mind which seems off topic to this thread, you might prefer to Search the Site

ADD a Q or A to THIS thread START a NEW THREADView CURRENT TOPICS

Disclaimer: It's not possible to 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 may be deliberately harmful.

  If you need a product/service, please check these Directories:

JobshopsCapital Equip. & Install'nChemicals & Consumables Consult'g, Train'g, SoftwareEnvironmental ComplianceTesting Svcs. & Devices


©1995-2017 finishing.com     -    Privacy Policy
How Google uses data when you visit this site.