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Heat Treating and Metallurgy Discussion of heat treatment and metallurgy in knife making. |
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#1
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154 CPM tricks, traps
I asked this in another place on the forum but maybe it is more of a heat treat question. And that is, do any of you use the CPM for springs? I know it is popular for blades but how about springs. My friend, Don Morrow, uses only ATS34 for springs but I do wonder since it would be easy to do the spring at the same time. Just curious...
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#2
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I use it for slip joint springs and it seems to work well. After heat treat, temper at 1150 for 2 hours.
Last edited by Bill Vining; 02-12-2009 at 11:51 AM. |
#3
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I'm with Bill. No problems.
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#4
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ok how do i heat treat the 1054 cm if i dont have a heat treater can it be done in a open fire then quinch in what can eney one help
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#5
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If you're talking about 154CM, no, it must be heat treated very carefully in a furnace. It's very touchy about proper temps, soaking, wrapping, etc.
Texas Knifemakers Supply will heat treat it for you. |
#6
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Bill/Don do you temper for 2 hours twice or once? Does it matter how quick you temper after you heat treat for example could you heat treat one afternoon and temper the next?
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#7
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For the springs, temper once for two hours. I temper my springs as soon as my oven cools down to temp.
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#8
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Quote:
That's what your kitchen oven is for, to perform the first temper as soon as the steel cools down to around 150 degrees following the quench. This is called a "snap temper", at a temp. 50 degrees or so below your actual tempering temp. It will relieve the stresses, then you can wait as long as necessary for the second temper. If you cryo, that can be done between the snap temper and the last temper. Since we started talking about a slipjoint spring here, you need to snap temper that to at least 350 to 400 degrees. I doubt your kitchen oven could maintain much higher than that. Assuming you'll do the actual tempering at 1150 as Bill suggested. Steel must be tempered after cryo without fail.The cryo adds more stress if done correctly. Last edited by Don Robinson; 03-03-2009 at 08:06 PM. |
#9
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thanks Don and Bill
Absolutely not!! The steel might crack due to the stresses introduced by quenching rapidly that figures I just thought I would ask. I temper as soon as the oven gets down to tempering temp but I have been tempering twice for two hours each sounds like I could temper just one time for two hours. |
#10
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I'll say it once more.
Never wait for a furnace to cool down to tempering temp. Please re-read above. Use your kitchen oven for a snap temper while waiting for the furnace to cool. One temper on a spring is probably enough, but two tempers for two hrs. each is safer. |
#11
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sorry Don, I am kinda hard of hearing. after I quench go straight to the toaster overn 150 degree or so, until oven cools down to tempering range. the duration for snap temper should be how long? I apologize to DaveL I did not mean to hijack your post. Sorry
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#12
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Quote:
Snap temper at least 350 degrees for 2 hrs. 150 degrees wouldn't help at all. Last edited by Don Robinson; 03-03-2009 at 08:00 PM. |
#13
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Great dsicussion, guys. I have been really curious about the spring treatment and Don's snap temper is one for me to consider for sure.
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#14
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Dave, anyone who does his own heat treat using only one furnace should always snap temper whether it's a blade or spring, or anything else made of tool steel.. You can't harm a piece of steel with a lower temperature treatment. It simply relieves the tension in the steel and helps prevent stress cracks.
Commercial heat treaters have heat treat furnaces for the quench cycle, and heat treat OVENS for tempering. The ovens won't operate at the high temps. required for a quench cycle and are designed to be used at lower temps., maybe less than 1,000 degrees or so. A quality heat treating service shoves the steel right into a tempering oven directly following the quench cycle, as soon as the steel drops to 150 degrees or room temp. Check out your heat treating service and see if they do that. I'm actually revulsed when people refer to a heat treating furnace as an oven. You can't heat treat steel in an oven. |
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blade, knife |
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