PDA

View Full Version : Quenching W2, Need Help.



Marko Tsourkan
10-17-2011, 09:51 AM
So, I quenched W2 in oil yesterday and it looks like the oil was too slow for the steel, so now I am thinking about trying to quench it in brine. For those of you familiar with the subject, can you confirm or refute the following?

- W2 hardens 1/8 deep, so no pregrinding is necessary on thin stock like 5/32 sheet.
- Heating brine will slow quench speed and be gentler on the steel approaching oil quench in effect
- Brine should be kept at room temperature vs heating it up
- Blade has be quenched egde first (as opposed to tip first)
- One should do interrupted quench, 3 sec in, 2sec out repeatedly until blade is cooled
- Brine quench forms a crisper hamon
- Brine quench is not worth the risk (of loosing the blade)
- Brine is best in 10-12% brine solution.

I would consider getting Park 50 if it wasn't so damn hard to obtain. I also like to use a bit more than 5 gallons of it, so I would need to buy 2x5gal buckets. I would like to give brine a try before taking a plunge.

Thanks in advance.

M

WillC
10-17-2011, 10:06 AM
You can get different grades of hydraulic oil. The thin stuff I have around for use in my hydraulic presses gives a relatively fast quench. East to obtain, here at least.

Mike Davis
10-17-2011, 10:12 AM
I had a looong conversation with Kevin Cashen(HT guru) last week about this. Brine helps to reduce the vapor jacket around the steel better than water. Brine is a violent way to quench, as it cools FAST and introduces a lot of stress to the steel. Brine can produce excellent results, and i have been experimenting with it quite a bit lately. One suggestion i have, is to get your tempering oven going before you quench...Go from quench to temper as soon as possible, as it can crack with the stresses induced just sitting there looking pretty. Parks 50 is not hard to get, just costs a bit. Maxim Oil has it in 5 gallons, and if you stay within the 300 mm range, you can quench right into the bucket. 50 needs to stay at room temp, no heating for quenching. Also Maxim make a product similar to Parks, called dt-48 i think. W2 has a high ping rate in water/brine, i would suggest trying it on a few smaller pieces before a blade, and use the brine in the 120 degree range.

Mike Davis
10-17-2011, 10:15 AM
Also i would suggest staying away from hyd. oils, transmission fluid, motor oil etc,. as it produces toxic vapors when heated that high. I must say, you can use pure mineral oil to good effect on this, W1, W2, 1080, 1095 for hamon, but formulated quenchants are better. A LOT of people use mineral oil to very good results, not as fast as #50, but a good alternative.

Marko Tsourkan
10-17-2011, 10:25 AM
Thanks guys.
I would need about 7 gal of oil for my quench container, so 2x5Gal buckets of Park 50. Mineral oil is a bit cheaper, but I still need to have it shipped, so the cost will add up.
I am not sure if I will be using W2 extensively (past what I have on hand), so would like to exhaust other options before procuring fast-quenchant oil like Park 50.

M

Mike Davis
10-17-2011, 12:25 PM
I really like W2, as i think it is the closest that we can get to the white steels of Japan. What are the dimensions of your quench tank? You should be able to get mineral oil at a local supermarket. Also, as i am sure many noted, there is a huge going on over at bladeforums about canola oil being an alternative to #50...I think it is a crap idea, but it does make a good quench medium for 52100, 1084, and more of the less fast steels...A tad too slow for 1095, W1 and W2...But still an alternative.

Delbert Ealy
10-17-2011, 01:22 PM
So, I quenched W2 in oil yesterday and it looks like the oil was too slow for the steel, so now I am thinking about trying to quench it in brine. For those of you familiar with the subject, can you confirm or refute the following?

- W2 hardens 1/8 deep, so no pregrinding is necessary on thin stock like 5/32 sheet.
- Heating brine will slow quench speed and be gentler on the steel approaching oil quench in effect
- Brine should be kept at room temperature vs heating it up
- Blade has be quenched egde first (as opposed to tip first)
- One should do interrupted quench, 3 sec in, 2sec out repeatedly until blade is cooled
- Brine quench forms a crisper hamon
- Brine quench is not worth the risk (of loosing the blade)
- Brine is best in 10-12% brine solution.

I would consider getting Park 50 if it wasn't so damn hard to obtain. I also like to use a bit more than 5 gallons of it, so I would need to buy 2x5gal buckets. I would like to give brine a try before taking a plunge.

Thanks in advance.

M


The depth of hardening depends partially on the speed of the quenchant, that is to say that if you use a quenchant that is not fast enough, you won't get the depth of hardening that you get with a faster quench. With the proper quenchant you can fully harden 1/4" thick W2.
Be advised that when interruping the quench, you need to insure that it stays in the quench long enough to form martensite, if you pull it out to early you won't get it hard.
I am with Mike in the idea that you might not need such a large quench tank. I use a 3 gallon tank for my kitchen knives and I can easily do a 330mm with a full tang. As long as your tank is big enough the only other factor is how many blades you will be doing in a short period of time. If you were quenching 100 blades a day I would go for a larger tank.
Salt brine is also not the fastest quench available, but since it is fast enough for W2 no worries.
Del

JMJones
10-17-2011, 02:30 PM
if you are going to quench in brine you may have to adjust the temperature down from quenching into oil. I was in a class with Howard Clark and we were quenching 1086M (fairly similiar to w2 as it is also has vanadium) into rain water and the hardening temp was 1435 and we broke the first two blades, Howard's and mine, he lowered the temp to maybe 1420 ish and the rest of the classes swords were fine.

I would also quench it as full thickness of stock and grind the bevels in after ht.

Also I think you have a way better chance of sucesss since you have a kiln to dial in the temps and soak time compared to using a forge. I dont think I would mess with brine if i did not have a kiln or salt baths.

Marko Tsourkan
10-17-2011, 05:15 PM
Thanks guys.

I am going to try quenching in brine and will report back. Will try it with and without interrupted quench and take hardness measurements to see what RC hardness I am getting.

Mike - I use 7Gal bucket for quenching. I have another one that I thought I could use for brine or fast oil quenchant. I like the height and the size.

John - I was to adjust the temp downward to 1425F for brine (I was austenitizing at 1450F with oil quench). Will try first on a scrap metal (should there be a ping), then on a small gyuto. See what happens.

M

JMJones
10-20-2011, 03:50 PM
Let us know how it goes,

Marko Tsourkan
10-21-2011, 08:32 PM
Let us know how it goes,

I got some salt and water, but I also got Park 50 for a plan B. :)

Well, the more I read on brine quenching, the more I wonder if I am willing to take a risk. So, I will start with Park 50 quenching a couple of blanks I profiled, and then experiment with brine on scrap metal.

Do you guys heat Park 50 or is it ready to use at room temperature (about 60F)?

M

Mike Davis
10-21-2011, 10:12 PM
Ready at room temp, optimal at 98 degrees. Room temp is fine though :) 50 will treat you well.

Bill Burke
10-22-2011, 08:32 PM
marko raise the temp a little with the oil. 1500 to 1550, the hamon will get pushed toward the edge more than with water so hold the thicker clay up on the blade farther.

Marko Tsourkan
10-22-2011, 08:40 PM
Thanks for the tip, Bill -

M

Don Nguyen
10-26-2011, 12:48 AM
Hi Marko,

I am by no means any bit knowledgeable on heat treating at all, but I've been reading this about a million times every day so far.

http://www.navaching.com/forge/heattreat.html

Diamond G
10-26-2011, 01:14 AM
I to am getting a W2 blade ready, mine is 5/32, and in a French chefs stle blade of 12". What is the optimum HT temp and what s the optimum tempering temp? Is clay required to get a good hamon, or can it be edge quenched to recive the same effect?

Thanks and God Bless
Mike

Mike Davis
10-26-2011, 09:12 AM
Edge quenching will give you a hamon per se, but not with the activity of a clay coated blade. The clay allows you to follow a pattern, but it doesn't follow the pattern...As much as it would be cool lol. I had one follow the clay almost perfectly but it was a 3/16 fighter. You might get some minor activity out of an edge quench but it will be minimal compared to clay.

Marko Tsourkan
10-26-2011, 09:25 AM
That is a good question. :)

From the little I know, the quenching temperature for W2 can be somewhere between 1400-1450F. Temperature will be higher for oil (as Bill and Devin pointed out) and lower for water. The soak time will be shorter in a forge and longer in an oven. The tempering temperature can be somewhere between 375-450F.

Every batch of steel will respond differently to HT, so I normally do a test-heat treat on scrap metal, measure hardness after quench (have to be fast with W2 as it might crack on you), then after first temper and then after second temper. Then I make adjustments as needed to get RC hardness I am looking for in a final product.

M

jmforge
10-31-2011, 11:08 PM
If you want a really active hamon, you should not go any higher than 1450 even with Parks. Guys like Don Hanson go as low as 1425, IIRC. I just did a long bowie skinny that is 12.5 inches long and 1 1.2 inches wide. I drew a line that ran parallel to the ricasso and brought my clay down to that point and then followed the curve of the tip.
I use my HT oven for austenizing and tempering, so I cannot put a quenched blade in immediately for tempering. I have to wait for it to cool down to where is is below 200F with the door open. I have never had a W2 or 1084 blade quenched in Parks go PING while waiting, I have had a very think Cru Forge blade tear itlself apart, however.:scared4:

Salem Straub
11-06-2011, 11:13 PM
That's true, Joe. With a thin blade such as most kitchen knives, lower temp yields more vivid hamon in fast oil. I recall Don saying that, too. It helps to reduce grain size with thermal cycles before the quench. Some of the best results I've seen come from 1500, normalize to a black heat, 1475, normalize to a black heat, 1425 and quench in Parks 50. John White's method. Thin clay, 1/16" or even less. The repeated normalizing will help prevent warpage as well. I often just snap normalize once, then reheat to a lower temp and quench.

One nice thing about using oil rather than water or brine for the quench is you get the opportunity to scrub the clay off and do a quick etch-check in ferric chloride to see if the hamon came out OK. This can save you some tempering time and money if the results are disappointing. Clay it back up, and back in the forge.

jmforge
11-28-2011, 01:50 AM
Salem, I am using John's clay application method now, which is to put fairly wet Satanite in a ziploc sandwich bag, cut off one of the corners and pipe the clay onto the blade like you were decorating a cake. With a modern shallow hardening tool steel like W2, the hamon is purely cosmetic, so the trick is to figure out the least amount of clay and arguably the lowest temperature that you can get away with so that you can control the pattern. If you get that right, John says that you can basically write your name on a blade and it will come out when you polish it. The good news about W2 is that the vanadium content means that you don't have to spend as much time and effort reducing the grain size as with some other steels unless you have really over heated it. For stuff that has been rolled to thin kitchen knife type stock and not blasted in the forge, you could probably get away with a quick and dirty 1200F spheroid "anneal" before you austenize and quench. I find that doing that after grinding has pretty much eliminated warping issues. According to Kevin C., if you really want to go hog wild, you quench the blade blank and then do a proper spheroid anneal where you step down the temp from 1200 or so to 900 or less over a few hours before grinding on some steels like L6. 1084FG, W2 and Cru Forge are the most complicated steels that I use, so I can get away with the 2 cycles and a "kitty litter" anneal for grinding.:D I up that to 3 cycles for damascus because I have been abusing the steel at temps above the point where the vanadium in the 1084Fg can control the grain growth for extended periods of time.