Corrossion Data for Stellite #6

[mahadhatu]

I am looking for corrosion data for Stellite #6 against Nitric Acid. I am interested in knowing the corrosion rates at various concentrations and if possible temperatures. Is this data available freely? if not, where can i buy it from?

Thank you,
Mahadhatu

 

[metengr]

Stellite 6 exhibits excellent corrosion resistance because it is a Cobalt-base alloy containing about 28% Cr with tungsten. I would expect no significant corrosion problems with this hardfacing material in an oxidizing acid solution, like nitric acid.

Your first option is to visit the web site below, and see if you can obtain corrosion data for Stellite 6;

http://stellite.com/

Considering the scarcity in corrosion data for this hardfacing material, and if the stellite.com source does not provide information, you might want to visit the Haynes International web site below. Haynes has a technical brochure H-2082C, which is the Ultimet hardfacing alloy brochure. Ultimet alloy has a Co-Cr base chemical composition that would be similar in range to the family of Stellite 6 and Stellite 6113 alloys (per the chemical compositions listed by stellite.com) . This brochure lists valuable information regarding mechanical property data and corrosion information.

http://www.haynesintl.com/guestbooknew.asp#Corrosion-Resistant Alloy

If you have no other source of corrosion information specific to Stellite 6, you might want to consider the information for Ultimet, as a guide. For boiling, 65% nitric acid solution (worst case), the corrosion rate is 8 mils per year for a cast product.

 

[unclesyd]

It was our experience that Stellite #6 was totally unsatisfactory for use in 55%-65% bleached and unbleached high purity HNO3 at any temperature. It was also unsatisfactory in 20% HNO3 at 100?C.

Once you added organics, especially the acids, the dissolution is straight forward in a hurry.

 

[mahadhatu]

Thank you Metengr and Unclesyd....
I also found this little pdf on the haynes website

http://www.haynesintl.com/pdf/h2087.pdf

According to this piece of information, the corrosion rate for investment cast Stellite 6 is 2890 mils/yr as compared to 8 mils/yr for the Ultimet Alloy in 65% boiling HNO3.

Thanks for your input.

 

[EdStainless]

Ultimet isn't a hardfacing, but it is very wear resistant. The Stelite type alloys use high carbon and the resulting chrome carbides to provide wear resistance. Ultimet relies on the work hardening of the cobalt based alloy and its excellent corrosion resistance. I have used Ultimet in 'Green Death' test loops with no measurable corrosion or erosion.

= = = = = = = = = = = = = = = = = = = =
Corrosion never sleeps, but it can be managed.

http://www.trenttube.com/Trent/tech_form.htm