All you numerical people out there may get a kick out of this article. Not the first time a simplified formula has led to problems.
http://www.wired.com/techbiz/it/magazine/17-03/wp_quant?current
Weldtek...Easy way to tell is to take part and drill hole to center of section. Insert thermocouple into center of section and a thermocouple to outside surface of part. Load the part with equivalent furnace, furnace load, same loading, # parts, # pounds, # trays or fixtures as manufacturer...
Unfortunately this is sometimes what you can expect when going to China to save pennies. Best bet might be just to send them back to your Chinese supplier for refund or replacement or better yet let them restore the surface. Why we as engineers work to aid our low cost structure competition...
SeasonLee,
I do not think the decarbed surface is related to casting. Go to a very reputable heat treater. Explain to them what you have and ask them if they would carbon restore the parts for you. They will most likely want to cut up several parts and measure depth and extent of decarb...
SeasonLee,
Parts were most likely decarbed from your China supplier.
The local heat treater should not be at fault because they are staring out with decarbed product. If you had known it was decarbed before you had sent it to the local heat treater, they could have carbon restored the surface...
Thanks for the feedback everyone. I suspected there could be issues with Carbon reinforced PEEK and steels, as I had seen problem in past when coupled with Aluminum. It is a great material just have to be careful in the application.
Yes, I am agreeing with second post with the exception that even when you sand out visible pits you will not have gotten rid of all the corrosion. You will need to etch the aluminum and invariably many of the pits will open up again.
That is because the corrosion tunnels down into the material...
Aluminum will pit by corrosion near salt water or salt air.
Just that simple. Even when anodized properly, the salt environment will still, after enough time, attack the aluminum. The correct way to determine if this mast is still usable will be very expensive. If pits are not too deep you...
Knowlittle,
You may crack your part upon quenching into water. You have too many sharp corners. A sixteen pound part into a bucket sounds real iffy. Without agitation it will not quench uniformly, soft spots and more chance to crack. Most compelling reason not to try this is it will...
Inco 909 has a very low,(less than half) of conventional superalloys Coefficient of Thermal Expansion (CTE). The material is often used in high temperature jet engine applications. Because it has no Chromium, it has poor general surface oxidation resistance as well as suffers from a condition...
Coatingsguy,
I would think you could create samples of alloy depletion by running them in an oxidizing atmosphere at varying temperatures and times. Your sample is most likely using an etchant to microscopically detect an alloy depletion zone. Even certain vacuum furnace conditions could...
