Carbide Material Resistant to Steam 2

[Tvolpe]

Hey everyone. Can anyone recommend a grade of carbide that would be resistant to high pressure steam yet have good wear resistence? This would be for a deep welloil drilling application

 

[racookpe1978]

What is the carbide doing, and what is its environment? A coating I'd guess obviously, but for scraping, impact, turning, flow resistance against ????

 

[tomwalz]

If that is all you, have for information about it we would start with our Super C grade. It is a submicron grade with about 10% cobalt binder. It has the toughness of the traditional C2 and the wear properties of the traditional C4.

It depends on how the carbide is wearing. I have a list of 17 things that contribute to carbide wear we specify grades based on this.

See

http://www.carbideprocessors.com/pages/carbide-parts/how-carbide-wears.html

High-pressure steam can be very abrasive particularly if it is carrying particulate matter with it. In that case, we would go to something like a Cermet 2, which is a very high wear material. It is essentially tungsten carbide with a post sintering, boron metalloid processing.

If you needed a tougher grade we would move into something such as the grades we use on stump grinders, sawmills etc. These are usually lumped together under the term nail cutting grades.

If corrosion is an issue, we can move into a grade with something like a nickel or nickel chrome binder for greater corrosion resistance than the traditional straight cobalt binders.

With the amount of money involved in downhole drilling and the economic penalties for failure, I believe I would specify very tight limits things such as grain size, porosity etc. I would also specify a HIPed material.

Note:
If you are going to use carbide as gaskets and braze it in place, the steel pretty well needs to be cut from pipe rather than machined from billet or plate. During the process of brazing, the assembly will probably reach 1500 F depending on a variety of factors. Typically, this is a long, slow vacuum process. During this process, there is a long cool down to provide an opportunity for stress relief arising from the difference in coefficients of expansion between the carbide and the steel. If the steel is still stressed from previous rolling, etc. that stress will also be relieved and the steel will move. Typically, the round hole will become a bit of an oblong by a couple thousandths of an inch.


Thomas J. Walz
Carbide Processors, Inc.

http://www.carbideprocessors.com

Good engineering starts with a Grainger Catalog.

 

[Tvolpe]

Environment is downhole oil drilling using steam to extract oil so you have heat as well as water vapor and a fine silica laden drilling fluid. Plus the usual sour gas. The carbide is acting as a sealing surface in a valve.

 

[tomwalz]

That is usually a spray application. A Google search for 'sour gas' and carbide "turned" up some companies that do this.

It really helps to know what the wear factors are. Carbide will resist wet steam much better than wet steam with relatively hard silica compounds.

H2S is hydrosulfuric acid. Cobalt bonded WC is pretty susceptible to acid attack. Nickel / Chrome might be a better choice if available.

Most vendors and suppliers will be happy to help you and many will probably tell you the truth.

Thomas J. Walz
Carbide Processors, Inc.

http://www.carbideprocessors.com

Good engineering starts with a Grainger Catalog.

 

[EdStainless]

As always your info is great Tom.
I used to build downhole equipment.
And though we weren't handling steam it was a hot abrasive environment.
We found that a coarse grain, Ni-Cr binder material worked best for the combination of corrosion and wear.

= = = = = = = = = = = = = = = = = = = =
Plymouth Tube

 

[tomwalz]

Thank you, EdStainless.

Coming from someone with your depth and breadth of knowledge that is flattering indeed.

Have a good 4th.

tom

Thomas J. Walz
Carbide Processors, Inc.

http://www.carbideprocessors.com

Good engineering starts with a Grainger Catalog.

 

[Tvolpe]

Thanks everyone. Your insight has been most helpful. It gives me a good foundation to start from. Very much appreciated.
Enjoy the holidays!!