Heat Treat Question

blgoode

blgoode

Joined
Oct 3, 2003
Messages
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I heat treated 1/8" NON ground 0-1 knife blanks for someone this weekend. I had a hard time holding the heat because they were unground and the flat 1/8" stock needed more heat.

Anyways, put on the rosebud tip and that solved the heat sink effect of the unground stock but It didnt act like my typical pre beveled 0-1 heat treated blades.

Just out of curriosity I RC tested them after 45 min at 425 degrees and they tested at 57RC. Not where I normally want them but not terrible either.

After the 2nd 425degree temper cycle and resting over night they all RC'd at 58 - 59:thumbup:

Why would the RC go UP if it was at 57 earlier??????
 
I'm assuming the blades were cooled to room temperature before you test them. Did you test them in several spots down the length of the blade ?
 
JBS TOOLMAKER said:
I'm assuming the blades were cooled to room temperature before you test them. Did you test them in several spots down the length of the blade ?
Click to expand...

yeah - they were cooled and tested a few spots :) I am O.C.D. you think I can just test once:p Just kidding.

After the final temper I tested them ALL about 5 times per blade on both sides down the length and they were very dead on anc consistantly 58-59. Not that I am complaining but I am mostly used to them being higher.....then getting softer.
 
That isn't much of a jump and is within the normal deviation of the test. (Kinda like one plus one is equal to three, for sufficiently large values of one.)

The only thing I can think of that would make it jump is retained austenite converting. That doesn't make much sense either, though it might be possible depending on how much it cooled and when.

Dumb question, why didn't you use your heat treat oven?
 
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