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Test method to identify chrome or tungsten carbide on shafts

2006

Hello,

I work in the paper industry and we recondition shafts. The shafts are 4340 steel and are coated with .004" chrome or tungsten carbide. When the shafts come in they are covered with dust, glue and dirt. We would like a cost effective, more scientific method to determine what the coating is? Since the reconditioning process takes two divergent paths depending on what coating is on the shaft. Some of you are thinking why not asked the user (i.e., shaft owner)? Many times they do not know.

Thanks for your time.
Jim Wollenweber

James Wollenweber
Paper Industry - Baltimore, Maryland, USA

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Jim -

I believe that portable XRF would work well for this application, especially if you were to "teach" the instrument what the coatings look like on top of 4340 steel which should be fairly easy to do. The downside is that this technology would cost you approximately $35K to purchase. However, you may find other useful applications for it down the road.

Terry Tomt
- Auburn, Washington
2006

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Just today I saw for the first time a ⇦this on eBay or Amazon [affil links] XRF machine. Probably not "cost effective" if you only do a few of these shafts, but a wonder, and cost effective when checking many parts. It's a hand held XRF "gun", costing $$35 thousand or so, but which will tell you quite exactly what you've got in just a couple of seconds.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2006

yes, both Niton and Oxford make nice versions of these portable XRF's. In fact, you can also sort aluminum alloys even better now because they have either helium purge or vacuum which allows you to analyze the light elements.

Terry Tomt
- Auburn, Washington
2006

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First of three simultaneous responses --

Forget the XRF JAMES show it to an experienced plater he should be in a position to just look at it and tell weather it is chrome or TC.

We do the same

ALL THE BEST,

Vikram Dogra
Irusha India - Chandigarh, India
2006

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Second of three simultaneous responses --

You should be able to differentiate between the two with a "spot test" which you can get from a text or searching this site. You will need to sandpaper crud off and give it a wipe with alcohol. It is not idiot proof, but it can work. Cheap also.

James Watts
- Navarre, Florida
2006

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Third of three simultaneous responses --

If you want to spend lots of dollars its OK but you don't need a highly sophisticated equipment. A simple cleaning of the shaft surface and a drop of hydrochloric acid will tell you. The acid will react in seconds over chrome and not over a WC coating. By the way, what's the difference in your processing of both? What do you do them, do you strip 'em, and if so, how?

Guillermo Marrufo
Monterrey, NL, Mexico
2006