Bath Temperature in austenitizing furnace is 1600 F, Tempering furnace is between 800 and 1100 F depending on the product being produced.
I'm not sure what you mean by what I am using for a Sloat on the bath... I assume you are asking what kind of insulating material I am using.. That is pea-coke, or graphite flakes depending on the product being produces at the time.
Material is everything from 1060-1080 steels to chrome silicon and chrome vanadium.
It looks like you have the float covered. We normally used granulated carbon, with a max size of 1/16" or coke breeze. We tried to keep the size as fine as possible both for protecting the lead and a reducing atmosphere above the bath.
I assume you are quenching in oil and then tempering in a another lead bath?
The only way I've been able to mitigate oxide formation is to force an oxide prior to preheating and Austenizing from the lead bath.
I do feel our float is too course, as it is probably more along the lines of 1/4", I'll have to look into that later.
Yes, I am oil quenching then tempering in a second lead bath.
How are you forcing oxide prior to austenizing? I am not using a preheat on this perticular furnace, but that isn't to say that I could.
I'm forming a pretty fair amount of oxide. It is fairly comparible than my competitions material, maybe alittle heavier. My first thought was to eliminate scale, but if that is not possible (as it is looking very tough on double lead) then I need to concentrate on forming a very tight adhering scale, so that it does not flake off later during the customers application.
I really appreciate your help so far Unclesyd. I'm fairly new to this industry, so any "old timers" tips or other information you can give would be very much appreciated.
You might want to take a look at the Heatbath sight especially the Covers. These are for salt baths but would work with lead. If the material were a water quench variety we could use a molten salt float that would protect the metal during the autenizing process.
Do you have an oven capable of 700F where you might experiment with forcing a steam/air bluing on the parts?
With your existing setup get some blued steel strapping and run it through your process to see how it behaves. If the bluing protects the steel then I would see if you could procure your materials already blued.
I don't have my old computer working yet so I'm at a slight disadvantage coming up with new approaches to your problem. Depend on you processing requirements and the end use of the steels based on the tempering temperatures you might get by with a Bainite Steel. No heat treating required.
