|
|
Register | All Photos | FAQ | Members List | Calendar | ShopStream (Radio/TV) | Search | Today's Posts | Mark Forums Read |
The Newbies Arena Are you new to knife making? Here is all the help you will need. |
|
Thread Tools | Display Modes |
#1
|
||||
|
||||
Anneal Question
I annealed a 1080+ knife blank yesterday that I wanted to heat treat again. I used my kiln to heat the blank up to 1600 (I overshot by 100 - it was at 1500 when I put the blank in and the temp creeped up) and let it soak for about 20 min. That 20 min includes the entire time it was in the oven. I wanted to make sure it reached temp before I started the actual soak time.
I then turned off my kiln and let it cool down slowly. I checked it and in about 3 hours it had cooled to under 500 degrees. I read on USAKnifemakers that you want to cool the blade at 50 degrees per hour to anneal it. My question is: Was that time slow enough or do I need to redo it and put it in some vermiculite? Mark __________________ Mark |
#2
|
||||
|
||||
Ideally, you do want to cool it at 50 degrees per hour but, if you do that in an electric oven, the oven needs to have a ramping controller. From the pics I saw of your oven last night I know it doesn't have that type of controller so you did the best you could under the circumstances. BTW, I don't think 1600 was too hot for annealing, just about right actually. Next time though, try the vermiculite or wood ash is even better if you can get enough of it. Either way, try to surround the blade on all sides with a minimum of 6" of the insulator and I like about twice that even better (I use a 55 gallon drum of wood ash and 24 hours to cool)....
|
#3
|
||||
|
||||
Mark,
1080 is a forgiving steel and the oven cooling should have left it soft enough to work. If you are merely re-doing the H/T then you didn't need to anneal. With the temperatures that you used I would think that you have some large grain size. Either way, I would recommend that you normalize the blade before H/T'ing Gary __________________ Gary ABS,CKCA, ABKA,KGA Last edited by Gary Mulkey; 12-01-2014 at 09:39 AM. |
#4
|
||||
|
||||
50 degrees per hour would take about 30 hours for an anneal. I heat to non magnetic and stick in a bucket of ashes. Takes about 2-3 hours to cool and gets it plenty soft to file or drill. Is this one you annealed just to re-heat treat?
|
#5
|
||||
|
||||
Quote:
Yes, I wanted to redo the heat treat. I wasn't completely satisfied with the process when I did it the first time. I was using a paint can forge and had a real hard time getting it to non magnetic. Mark __________________ Mark |
#6
|
|||
|
|||
30 hours? That is factory coarse spheroidization. After a coarse spheroidization, you would have to normalize it again and then re thermal cycle. A fine shperoidization can be done with the ramping controllers. First, normalize by 1600F, then air cool. Then again at 1500F. Then again at 1425F. Then into the oven at 1425F, soak for 10 minutes, ramp down to 1200F at a rate not to exceed 50 degrees per hour, hold at 1200F for two hours. Turn off kiln and let cool to room temp. Will file/drill/grind like butter. You don't have to turn off kiln and let it cool...you could actually quench after the 2 hour 1200F soak, to help speed things up and get back to work. Total time from 1450 down to ready to go.......7 hours. If you wanted to just shut the kiln off and let it cool after the 2 hour 1200F soak...you might as well wait overnight....so it COULD be a 24 or 30 hour project.
If no controller, normalize at 1600F, air cool. Again at 1500F. Again at 1425F (numbers can vary and be approx). Bring it up to 1450F, or just past non magnetic, and stick into a bucket of wood ash or vermiculite or other similiar product to cool overnight. It will be normalized, "grain" refined, soft, and ready to harden. Last edited by samuraistuart; 12-01-2014 at 11:01 AM. |
#7
|
||||
|
||||
Mark, for under 100$ we can wire ya up a PID controler.. Made a world of difference for me.
Nate |
#8
|
||||
|
||||
Quote:
I was thinking about that. I sent an email to SKUTT to see if they had a wiring diagram for the oven I bought. I think all I need is a relay, thermocoupler, and a PID contoller. mark __________________ Mark |
#9
|
||||
|
||||
Mine worked with the existing thermocoupler..
It's easy to do the wiring,, programming the PID took a little more time for me but I figured it out... Nate |
Tags |
blade, drill, easy, file, first time, forge, grind, heat, heat treat, hot, knife, knife blank, made, make, paint, steel, wood |
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests) | |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Anneal ATS-34 | Frank J Warner | Heat Treating and Metallurgy | 7 | 10-06-2008 01:19 PM |
bronze anneal | birdog4 | Heat Treating and Metallurgy | 2 | 02-18-2006 09:52 AM |
anneal or not? | Coutel | Heat Treating and Metallurgy | 6 | 07-20-2005 09:27 AM |
anneal and normalize | Omega | Knife Making Discussions | 1 | 03-30-2003 07:57 PM |
anneal d2??? | Cliff Krug | Ed Caffrey's Workshop | 5 | 09-28-2002 07:36 PM |