|
|
High-Performance Blades Sharing ideas for getting the most out of our steel. |
|
Thread Tools | Display Modes |
#16
|
|||
|
|||
As I remember the blade was 9". Thickness was likely about 5/32" or slightly more. 3V comes in odd sizes, but that's about what I use for a knife that length and style - single edge fighter.
|
#17
|
|||
|
|||
bainite, how?
Daniel,
This is interesting. How would a snap temper produce bainite? From all I know, steel must be austenitized and then be held for some time slightly above martensite start to produce bainite. Thanks, John __________________ John Frankl |
#18
|
|||
|
|||
After the initial quench to room temperature there is retained austentite. Cryo would convert this to martensite. Reheating (even snap tempering) will relieve some of the internal stress. But it could induce some of the austentite to convert to bainite.
This isn't really a bad thing, but for most applications it's probably not be as good as getting more martensite. However we are dealing with fairly small percentages, depending on the amount of retained austentite after the quench. I was looking at micro-photos of one of my steels last week and was surprised to see more bainite than I expected in just a normal oil quench and temper. Daniel |
#19
|
|||
|
|||
thanks, and ?
Thanks Daniel. I'm not sure what steel(s) you're using, so this discussion remains somewhat hypothetical. But, from what I have read, retained austenite transforms to lower bainite under the following two conditions: (1) a tempering temperature between 450-700F, which is much higher than most snap tempers (and even most full tempers); and (2) when retained austenite has not already been transformed to martensite by cryogenic treatment. In theory, again, I would think your blades meet neither of the above two conditions. Of course, theory often breaks down in the real world. Any ideas why you are getting bainite when the theory books say you should not?
John __________________ John Frankl |
#20
|
|||
|
|||
There are still a lot of unknowns about steels.
The temperatures which you are using are for a straight carbon steel. Most alloying elements lower both the martensitic finish temp and the bainite temp. Supposedly lower bainite can form as cold as 125C !!! Those particular samples had not been cryo processed. So it was probably #2 of the mentioned possibilities. The steel had been tempered to 300F for 30 min. Daniel |
#21
|
||||
|
||||
Please post as soon as you start making bar stock available. I am definitely interested.
__________________ "People sleep peaceably in their beds at night only because rough men stand ready to do violence on their behalf." - George Orwell "Kind-hearted people might think there was some ingenious way to disarm or defeat an enemy without too much blood. This is a fallacy." - Carl von Clausewitz |
Tags |
blade, forge, knife |
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests) | |
|
|