The Damasteel Got Here !!!!

Obviously the air quench is not good for this steel , and I think the aluminum quench is not a fast as you think. The oil quench gives an even better fracture surface( very uniform ) and the proof is that the hardness is up.Now you have to decide if that hardness is what you want . Work out a better system for getting the steel out of the foil. Vegetable oil ? wouldn't it be better to get some proper quenching oil ? Anyway you are learning Roger. Very good.
 
What oil might you suggest to me ? I would like to try one with 'in the packet' oil quench - just to see how it turns out. The al plates do not contact all six surfaces, only the two largest. If that is not good enough for a flat test piece how much better could it possibly be trying to quench a distal taper that is beveled (?).

As far as getting it out of the packet: it is not just a matter of time between oven to quench but also warp caused by not having the point straight down at all times. Its real tuff to figure that one out but can be done. Our gadget inventer Steve Sando might be able to help with that problem.

I am reluctant to shut the door on air quench for this steel. I don't have a fearsome blast of air coming from my vertical wind tunnel. It could be better but I have gotten excellent results using it to quench ATS-34. A more adequate air flow than I currently have may show improved results for RWL-34.

RL
 
RE the foil packet problem

I've been puzzling over that one. There is one critical piece of information the metal guys won't tell us, it must be some kinda secret: how much time do we really have?

The closest CCT graph I personally have to look at it is for ELMAX. (It's close in temps and RC, but not elements). But it looks to me like you have more than 10 seconds. The other air hardened steel chart I have shows even more time! I know one S30V blade I fumbled around for a fair bit of time (Seemed like forever but was less than 10 seconds) into the oil and hard as a rock. Although I believe S30V is easier to treat.

For one of your experiments (If you are not so tired of them and I wish I had more time to play with my oven) is to place 2 samples in a packet and one in another. Drop one packet straight in oil. From the other remove them both. Drop one in the oil ASAP and hold the other in the air for 10 full seconds. Then drop. If the 10 second guy is not materially different then maybe our problem is imagined.

(PS I know of at least one guy here that oil quenches in the packet, but I don't know what kinda knives.)
-------------------

I have been puzzling on this remove from the packet problem for some time.

Here's what I was going to do for my next one. Make the bag loose (and add more burn paper). Keep a good 1" of free space on either end. When the time comes, grab with pliers, cut the end off and shake it out into the 'basket' and lower into the oil.

Oil cools sooooo fast that the packet delay might not matter.

Ohhh heck, I don't know the whole thing is soo fascinating - mete is a lucky guy.

Steve
 
I just got through snap tempering #7B and it is now in cryo. It is the same HT as #7A (oil quench) except that this piece was foil wrapped, quenched foil wrapped, and the oil temperature was 140 F. (7 degrees less than #7). All other specs are the same.

I will see this HT through but it has been comprimised. For the first time, and I do not know why, my foil packet must have had a leak or developed a leak because upon removing after snap temper the test piece was coated with oil and there was a very shallow amount of pitting. I easily ground it off, Rockwelled and put in cryo.

Rockwell for this one after snap temper (350 F. / 1 hr): 60 HRc

I'll complete the process for this one and post results but I think it needs to be repeated with an uncompromised foil packet. DARN.

RL
 
Sample #7B is complete. See above post for differences between #7A and this one.
-------------

In addition, for the purpose of full disclosure, #7A was simply dropped into quench while the #7B foil packet was held by tongs in the quench and moved back and forth in a cutting motion.
-------------

Deep cryo for this one was 14 1/2 hours
-------------
Rockwell after snap temper: 60 HRc
After cryo: 64 HRc
After first temper: 63 HRc
After final temper: 63 HRc
-------------

Fracture picture is here (both #7A and #7B are here): http://riflestocks.tripod.com/steelgrain7a.html
-------------

It appears the procedure repeats.

Because I believe my foil packet was not air tight, or tight enough, I will do one more foil wrap oil quench using this steel. In the mean time I will be searching for a local source for borax and intend then to do one RWL-34 sample using that (more than one if needed). Then, if using borax proves good I intend to move on to ATS-34 in a cross test using the same perameters we have used for our best RWL-34 results.

Mete, all negative or positive inputs from you are very valuable. Please pipe up if you feel it will be of benefit.

RL
 
When it comes to quenching a blade it isn't a good idea to just drop it in the tank, too much chance of warping .Point down or edge down and moving it or using a circulation pump is the way to do it. Well, the hardness is still there, that's good since you don't have to worry about getting it out of the foil quickly. Keep going.
 
Thanks Mete and yes of course I would not be dropping blades in but thought I would just let that rectangular test piece slip out and into the oil to get it there quickly.

I suppose it is a good time now to also speak of this: my thoughts are that regardless of how well a small rectangular and parallel test piece quenches with a foil wrap oil quench it isn't going to say very much about how a tapered and beveled blade will quench in foil. I am hoping I can find borax locally and that it works well.

RL
 
Roger
a hardware/lumber store should have borax, it use to be in all the
homes years ago for cleaning I believe, that's where I got my TSP
the borax I have I really can't remember where I got that I've
had it so long.
when you get the final write up e-mail it to me and I'll post it..:)
 
Dan, I found some in the country, away from the city concrete. Hey, it turns out borax is great for killing fleas too. I've always had pets, dogs or cats, and have also usually been cursed by having some carpet in the house and over the years I have gotten fleas in carpet about three times. I used to put Seven dust on the carpet but now am told borax will do the job. The down side is I am told borax is poison to pets too. Borax on my socks for a few minutes seems better than Seven dust. Besides, you can wash your soaks in borax.

I hate to sound like some country hick that goes he-he-he all the time (I really am) but if you got pets and you got carpet you know what I mean.

RL
 
I've got a bottle of lemon juice in the fridge. Would that be a good corrosion test for this heat treated RWL-34?

RL
 
Roger
I'd run it over a 220 belt,cleaning it and heat it up just a bit,
stick it in water to cool and set it on your bench w/out drying it
for about 30 minutes and see what happens first.:(
 
Dan, I'll do as you suggest first.
-----------------------

Heat Treat Sample #7D:

This one is air quenched while in the packet
-----------------------
(0.75 X 1.5 X 0.138 inch RWL-34, foil wrapped and placed in cool oven)

Ramp to equalize

1400 F. / soak 7 minutes

Ramp to target

1950 F. / soak 25 minutes

Rapid air quench to handling temperature (quenched 'in the packet')

Snap temper immediately: 350 F. / 1 hour

Deep cryo: 15 hours

Temper after still air warming to room temp.: 400 F. / 2 hours

Temper: 400 F. / 2 hours
------------------------
Rockwell after snap temper before cryo: 60 HRc
Rockwell after deep cryo: 64 HRc
Rockwell after first temper: 63 HRc
Rockwell after final temper: 62.5 - 63 HRc
------------------------

The #7D picture is at the bottom of the link page.
Fracture Picture: http://riflestocks.tripod.com/steelgrain7a.html

RL
 
I tried borax as a atmosphere control. After an evening with it I decided not to persue it further for the near future.

I went up a hurried learning curve with it and must say I had no previous experience with borax so do not wish to imply it will not work well for what I was hoping for but will leave it for another time.

The closest I got to atmosphere control was to heat a sample of D2 to something like 800 or 900 F. (I did not take notes for this and may be wrong in memory of temperature) and dip it into borax and place it back into the oven. Somewhere between 1400 and 1500 F. I checked it and it had turned to glass in appearence, covering most but not all the steel sample. Before this the borax had expanded in volume, much like the house hold insulating product Great Stuff does. After retrieving from the oven I DID NOT quench but rather let still air cool. The borax was too think in my thinking to allow for a proper quench of the steel and it did not cover enough of all the sample piece to protect from oxygen during austinitization. In addition, it cooled to very hard. I beat it with a hammer and put it to the grinder and was very impressed with the stubbornness of the molten and cured borax. I will say this: it sure is pretty looking.

I gave the remaining to my Lady so that she might do my laundry using it.

RL
 
RWL-34 Heat Treat Sample #8:

This one is oil quenched while in the packet and the oil IS NOT pre-heated.
-----------------------
(0.75 X 1.5 X 0.138 inch RWL-34, foil wrapped and placed in cool oven)

Ramp to equalize

1400 F. / soak 7 minutes

Ramp to target

1950 F. / soak 25 minutes

Oil quench (quenched 'in the packet'), oil temp: 71 F.

Snap temper immediately: 350 F. / 1 hour

Deep cryo: 12 hr 50 min.

Temper after still air warming to room temp.: 550 F. / 2 hours

Temper: 550 F. / 2 hours
------------------------
Rockwell after snap temper before cryo: 58 - 59 HRc
Rockwell after deep cryo: 64 HRc
Rockwell after first temper: 60.5 HRc
Rockwell after final temper: 60 HRc
------------------------

Fracture Picture: http://riflestocks.tripod.com/steelgrain8.html

RL
 
You've done so many tests now it's getting confusing. I don't understand how you can get slightly higher hardness when air quenched in the packet than you do in the oil. Are you using prepared packets or plain foil ? It's probably time now to experiment with pieces with a bevel ground like a knife. How do you open the packet do you just unfold it or could you cut off the end with a large sheet metal shears ?
 
Mete I'm thinking that
in the oil you'll get a boil around the blade trapping Heat
slowing the quench.

kind of like warm oil (I believe) will cool faster than
cold oil, just because of the viscosity of the oil
it will move around faster dissipating heat faster,
we know if to hot it won't cool fast enough.
any thoughts?
 
All packets are made of foil by myself. They are consistant enough from test piece to test piece.

Dan, it is true, the pre-heated oil gave a higher Rockwell than the 71 F. oil did (as tested after snap temper). However, the grain structure looks much better than the test piece quenched in pre-heated oil (~135 F.).

I am finalizing a air quench today of the same HT specs as this last one (#8). The increase in temper to 550 F. has been to establish a procedure for ending up with 60 - 61 Rc for this steel.

If the air quench turns out well it will be, as Mete says, time to move on and I will settle on the air quench as the one I will recommend out of all the tests so far conducted. I would like to do a cross test on ATS-34. Then two things remain: do a real blade and also continue working on a better quench method.

I'll try to get a better picture of the last test (#8) and the upcoming air quench (#8A).

RL
 
RWL-34 Heat Treat Sample #8A:

This one is air quenched while in the foil wrapped packet.
-----------------------
(0.75 X 1.5 X 0.138 inch RWL-34, foil wrapped and placed in cool oven)

Ramp to equalize

1400 F. / soak 10 minutes (see note at bottom area of post)

Ramp to target

1950 F. / soak 25 minutes

Rapid air quench (quenched 'in the packet')

Snap temper immediately (handing temp., guessing at ~> 120 F.): 350 F. / 1 hour

Deep cryo: 17 hr 15 min. (> 12 hours not essential and no added benefit)

Temper after still air warming to room temp.: 550 F. / 2 hours (all tempers, snap included, were 5 to 7 minutes greater than actually specified)

Temper: 550 F. / 2 hours
------------------------
Rockwell after snap temper: 60 HRc
Rockwell after deep cryo: 63 - 63.5 HRc
Rockwell after first temper: 60 - 60.5 HRc
Rockwell after final temper: 60.5 HRc
------------------------

Fracture Picture: http://riflestocks.tripod.com/steelgrain8.html There are both the un-heated oil quench and the air quench on that page.

Note: I could kick myself for doing this but I increased the equalize time by 3 additional minutes for this air quench test. That makes this test more different than the oil quench than just the type of quench used. I knew better but did it anyhow and wish I had not.

Regardless, no test so far has proven as good as test piece #7B ( http://riflestocks.tripod.com/steelgrain7a.html ). That was an oil quench with a defective foil packet, an unnoticed pin hole or something that caused a leak. This is not a solution to finding a proper 'in foil' quench method because an inconsistant quench causes severe stress and varying transformation among the surface areas. A pin hole or a purposefully made slit in the packet will not allow all surface areas to contact quench at the same moment in time.

For me, after all this I am convinced that the steel is best quenched out of the packet and that optimum grain will not consistantly be acheived without doing so. I am also convinced that if quenched while in the packet the difference between pre-heated oil quench and rapid air quench favors the rapid air quench and I would feel more confident air quenching a foil wrapped blade than quenching foil wrapped in oil. As I stand now with what I have seen thus far trying to properly quench a foil wrapped steel is like holding a cat by its tail. There will be a lot of wiggle because of varying atmospeheric insulation. From my experience with this series of testing the aluminum plate quench was disappointing but I must admit that I may have given up on it earlier than I could have however, the same basic theory I have concluded for myself would apply to the plates in that not all surfaces of a tapered and beveled blade will contact the quench media (aluminum).

HOW THE TEST PIECES WERE BROKEN: Early on I used a dremel cut off wheel to score the pieces after heat treat. I soon learned it was much easier and more consistant to use a hacksaw to score the pieces BEFORE heat treat. All pieces were broken while clamped tightly in a vise with the score line upward facing the hammer blow and with the score line against the edge of the vise jaws (score line not hanging away from vise jaws but not hidden by vise jaws). All pieces were scored on one face and the two edges. One deliberate blow of the hammer was used and I strived to keep the head of hammer parallel to the test piece and centered.

In all cases, save none, the better looking parts of the break were always on the underside, the side opposite the hammer contact side.

RL
 
Roger
let me know if you want this posted on the site? or edit
as you wish then let me know..
:)
 
Dan, wait for Mete's responce and if he doesn't grin at it post it 'as is' (do edit grammer, spelling, and conciseness as you see best).

RL
 
You must log in or register to reply here.
Back
Top