OT Castings wont harden

P

Pete Allan

Joined
Oct 29, 2003
Messages
220
I got in a batch of 1095 castings and did all the drilling and tapping then tried a sample hardening like I usually do. I heated to nonmagnetic then quenched in 160f quenching oil and touched with a file. It was sort of hard in spots and rather soft at other spots :grumpy: Now normally these parts are glass hard before the tempering stage.

I have heard of castings needing "carbon restoration" but have not needed this process before myself. Am I thinking right? Is carbon restoration more or less just case hardening without the quench?

I have put a good bit of work in these parts already so I just don't see recasting them if I can get out of it.
Thanks
 
Are you sure you have 1095 ? If you have decarburization you can add carbon to replace lost carbon .Assuming you have decarbed 1095 , you could use Kasenit to add carbon to the surface and re- heat treat .You can find Kasenit at www.brownells.com All you need is a torch[ propane if they are small parts] and follow the instructions.
 
Unfortunatlly the parts will be flintlock frizzens and need to be hardened rather deep. A friend of mine has access to a spectrograph so I can get the parts tested before I go through any more work or expense.
Thanks
 
Pete, you have more experience with this than I, but is it possible that the foundry did not flux the steel prior to the pour and some separation occurred.
 
Peter In an induction furnace the metal is "running" in the melting pot some what like liquid does in a glass with a blender in it only the botton is stiring upward and the top is stiring downward and they meet in the middle. When a foundry has a problem it could be they simply poured the wrong metal or that they are not adding enough new metal to a melt to make up for natural element losses during the melt. Just before a pour a can of additives is dumped into the running melt to aid in degassing and to bring the carbon and silicon levels up to spec and this amount could easily been figured in error -- been there done that as they would say.

Running a large induction furnace is really a lot of fun -- just like having a pet DRAGON :D
 
Pete
did you check for nonmagnetic then quench
or re-heat to recover the loss of that heat? that could be a problem in it self, very touchy steel and I'd
drop that oil temp down , 1095 needs a fast drop in temp to work the best.
a salt brine may work better if you don't want to use water.. JMO :)
 
Dan We have done this for years without a problem so I feel I have a metal problem now I just hope to solve it without recasting. Normally the cast 1095 will end up in pieces if quenched in water so yesterday I did try 1 piece in a water quench and found some hard spots but also found some very soft spots that didn't resist a file at all. When working with castings sometimes I get the feeling there is black magic involved when trying to get things just right.
There is always a way to work things out as a friend of mine has deminstrated -- he makes VERY large batches of fire strikers and to avoid costly material and forming problems with tough material he uses 1020 and sends the whole batch out for deep casing. This may sound like cheating but I have not seen any that out spark his strikers.
Thanks again for every ones suggestions :D
 
I forgot to mention (senior moment) that at the same time I heat treated some 1095 springs that were cast quite some time ago and after an 850f temper I tried them in some locks and they worked just fine so that was my bases for feeling the metal was a problem.
 
:) you don't know until you ask


I was wondering why though? you'd get soft spots in it? as the vat is mixing at the time of the pour. or you got the bottom of the barrel sote'a'speak or some wrong stuff was mixed in I can only guess

I think you've solved your own problem.
 
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