Well the grinder upgrade was good or bad depending on how you look at it. I know have 18 blades maybe a few more hanging around in an assortment of materials after having way to much fun trying out a belt moving at 62 mph or about 5200 SFPM and only lost part of one finger nail 7) AEB-L fillet knives - air quench with plates 1) AEB-L bird & trout - air quench with plates 1) AEB-L Honesuki kitchen knife - air quench with plates 1) 1084/15N20 Damascus mini cleaver - 130F Canola oil 3) skinning knives in A2 - air quench with plates 1) Large camp knife in 01 - 130F Canola oil 3) assorted camp knives in 154CM - air quench with plates So too the task at hand besides finding missing knives the heat treating one at a time routine is not going to fly. When performing heat treating on multiple knives do you extend the soak time by a couple minutes each for air cooled and a minute for oil quenched? Really want a routine figured out in advance here so I don't mess up treating these little projects. I do know last step is to ramp up or down to 1650F and anneal a few T1 planer blades that will be turned into utility type knives. and still have to sort out how to achieve a cooling rate of 35F per hour down to 1000F. Oh this is with the Evenheat KO 22.5 with TAP
Your really going at it . To save your fingers I use a push stick. For heattreat im no help I send mine out for that less headache for me.
John, I sometimes do three or four blades in the HT oven at once. I can pull the first one, quickly close the door and oil quench. In 15 seconds the door is ready to be opened for the next one. The thermal mass within the oven allows the temperature to recover very quickly; at least according to the temperature controller. Opening the door does appear to drop the air temperature inside the oven quite radically, but the blades inside do not change in colour so I am thinking their mass keeps their temperature more stable. My "furniture" holds four knives. Really, I would prefer to be ultra-lean and make one knife from start to finish before moving on, but heat treatment is a bit of a hurdle and doing a few at once kinda makes sense. My sensei want to reprimand me now. The waste is that I have a half dozen heat treated blades that haven't yet been worked on. Flow...Grasshopper... Dan
That is good to hear, I was looking at the color as well and was thinking maybe I was being more hopeful than honest that the next blade was good to go. Didn't help that a couple videos I watched always show guys doing only one knife at a time which seemed odd when so many makers do several knives all the same in batches. The worst part of this is it means I will have at least four knives to mirror polish all at the same time, oh joy
I typically add 5 to 10 minutes to the soak on air quench steels. This just makes sure the oven holds temp long enough to allow me to plate quench, and cool my plates between knives. I'm not worried about losing temp from opening the door because as Dan said, the thermal mass of the blades, rack, and oven hold enough heat to recover very quickly. Faster than I can quench and be ready for the next one I'm sure. The evenheat information I received with my oven was not complete, but you should be able to email Evenheat for full info or find the manual online. I had to email them to get the info on how to change my controller from C to F as its not in the normal manual. You can set a cooldown timer just like your ramp up timer I believe, I think its just done in reverse. Evenheat should be able to instruct you on that. If that doesn't work, you could always set a top hold temp, then a lower hold, progressively down, this would keep the oven from cooling too fast. If all else fails, you can just ramp up, hold for a while and then shut down. If the door stays closed the kiln retains heat for a pretty impressive amount of time. From 1950, the inside of my forge is still noticeably warm to the touch 8 hours later.
Found old instruction manuals and one forum post to realize I have been over thinking this annealing issue. 6 mastercraft planer blades Steel type - T1 18% HSS Step 1 - Preheat - 1525F hold for 5 minutes . Preheat as slow as possible according to ASTM A600 and figure starting from room temperature the heating rate of 9999 or as fast as possible should be slow enough. Step 2 - Annealing temperature - 1625F hold for 5-15 minutes or 45 minutes per inch on larger objects. steel must be thoroughly soak so that temperature is even throughout the part. step 3 - Cooling rate or target temperature is 1000F, ramp rate is 35F/hr from there oven is off and cooling temperature is not critical. the software should be able to figure this out I think, but going back to review ramp rate just to be sure it is hour specific.
I've annealed a bunch of farrier's rasps. Popped them in, ramped up to critical. Turned the oven off and kept the door closed overnight. Checked on them the next day. Soft enough to drill and file pretty easily.
I thought of tossing in a couple files I bought and wrecked first use but they might have been under hardened originally or case hardened junk. This T1 is a whole different breed of animal for annealing and hardens far too easily. But the idea of a 65 Rhc carving knife is appealing for use sharpening not so much. Thinking I might try may hand at small carving knives or chisels for steel. One of those what the heck projects lets see what happens.
I've annealed AEB-L the same way. I had a broken full tang and re-purposed it to a hidden tang. Overnight did the trick. I'd give a shot and see.
In progress now, the ramp down is working perfectly. Only thing I noticed is the high cycle rate of the coils but that is nothing I am going to get concerned with. at this point temperature has dropped 70F and going down steadily, watching the graph is lots of exciting
Forgot the update the T1 steel was as easy to drill and grind as any steel. Started off not knowing what to make with the planner blades and now have a couple tiny swords and one chisel for steel with any luck
