Advice needed on l6 steel

delbert ealy said:
These are the certs from the last batch of carpenter L-6 I bought.
If someone could post their certs from a crucible batch it would be helpful for comparision.
C .710
Mn .560
P .016
S .002
Si .410
Cr .920
Mo .300
Cu .150
Ni 1.75
Fe Balance
Thanks,
Del
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here is the certs from my new batch of L6 from Crucible

C: 0.72
Mn: 0.54
P: 0.012
S: 0.009
SI: 0.26
NI: 1.46
CR: 0.79
MO: 0.14
CU: 0.23
 
Question for Kevin, Met and Delbert. Is there a huge advantage in using L6 as opposed to W2? I have read somewhere that W2 does pretty well in the Charpy tests and you can't argue with the edge it takes. How much additional impact resistance do you get from the nickel in 15N20 when combined with W2 in damascus, understanding that with the common sizes of 15n20 used, you still have mostly W2 in the billet?
 
For impact or chopper use L-6 is much better . For wear resistance W-2 is better.The nickel really does the job.
 
mete said:
For impact or chopper use L-6 is much better . For wear resistance W-2 is better.The nickel really does the job.
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So what percentage of 15n20 with its nickel do you need in W2/15N20 damascus to impart a bit of that impact resistance without sacrificing the wear resistance and fine edge of the W2?
 
koyote said:
The vermiculite and rebar "assist" is VERY hit or miss. And I have gone through way too many drill bits :( I've messed around with various methods, and ... well, it's hit or miss. For reference, it's 1 inch rebar, and a fair amount of it- and it works for crap on thin stock. I've considered piling some wool and cement in a spare steel box and using the rebar to keep some temperature control for a "cooling oven" but the heat loss from opening it up seems like it would kill the effect. I'm putting a kiln on my list, but since most of the L6 I actually do is large blades, I have to go all out for a big kiln. And cash money is really tight with wife in nursing school.

I have tried very hard to avoid the "everything with nickel is L6" fallacy, mostly due (with much thanks) to kevin and mace kicking my butt on terminology very early on a couple years ago. So I try to be exacting on the differences, but in truth I think that all three of these steel make excellent "monosteel" blades.


If I ever find a good source for the mythical .120 15N20 stock, I'll put my son in hock and find a way to grab a couple hundred pounds!
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I use a lot of L6 and 15n20. All in the form of saw blade.
Gone through many drill bits. Tried different methods to get L6 soft and found two methods that work well for me. 1 1/2 " or 2" thick ceramic wool for a couple of blades or a kiln for larger numbers.

Two pieces of wool. I'll bring the steel up on one piece and sandwich it between two. That is as soft as I can get it. I let it cool overnight.
For a larger number of blades I'll stack them in a kiln, bring the temp up, close the kiln and let the temp drop overnight, about 12 hours.
I've heard that one can do it in two three hours but I can't and I'm in no
rush.

Scott
 
I've wondered why i've had such bad luck with a variety of drills when used on Admiral's 8670. I thought it was the drills. I've been using 8670 for a while and really like the blades it produces. I'd like to find some real L-6 but no luck yet. It seems a real shame that some of the best steels are so hard to find but that's part of the adventure.
 
Kevin R. Cashen said:
I have done some experiments with making my own lawn mower blade inserts and such with L6 and the ones that I decided to take a short cut on and just allow to air cool had no better strength or toughness than any other steels, but the ones that were heated, quenched and tempered properly have allowed me to run over just about anything with my mower and keep going.
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Ha! :D That's just awesome! I try to keep the blades on my push mower sharp enough to slice paper, and basically touch them up every time I mow. (can go much faster this way) You don't know how many times I've thought about making my own blade from L6 or something. It's cool to hear someone's actually done it.

In fact, I'd be really curious to hear anything you learned from this. Did you try a couple different hardnesses with the properly treated martensitic blades? (if so, what?) What kind of edge geometry did you apply?
 
Thanks Mark
I live 10 minutes away from there Ohio location and had no idea. I will be making a run over there to see what kind of deal I can get
John
 
jdm61 said:
So what percentage of 15n20 with its nickel do you need in W2/15N20 damascus to impart a bit of that impact resistance without sacrificing the wear resistance and fine edge of the W2?
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Do not try to put a water hardening and oil hardening steel together in a damascus unless you want all sorts of problems, the properties are enough different that to harden one properly you run the risk of cracking the other, there may be other working properties that are compromised as well

-Page
 
jdm61 said:
So what percentage of 15n20 with its nickel do you need in W2/15N20 damascus to impart a bit of that impact resistance without sacrificing the wear resistance and fine edge of the W2?
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The nickel doesn't migrate very quickly at all compared with carbon, so you will not have a homogeneous solution. You will have bands of high nickel, and bands of low nickel. I don't think that would increase your impact resistance much at all.
 
james7729 said:
I've wondered why i've had such bad luck with a variety of drills when used on Admiral's 8670. I thought it was the drills. I've been using 8670 for a while and really like the blades it produces. I'd like to find some real L-6 but no luck yet. It seems a real shame that some of the best steels are so hard to find but that's part of the adventure.
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James I drilled 75 holes 1/4" dia in Admiral's 8670m with almost no wear to the cheap chinese drill bit, are you sure you have 8670m?
 
sunshadow said:
Do not try to put a water hardening and oil hardening steel together in a damascus unless you want all sorts of problems, the properties are enough different that to harden one properly you run the risk of cracking the other, there may be other working properties that are compromised as well

-Page
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Page,

I think the Ac1/Accm(Ac3), expansion rates, MS start of W2 and 15N20 match up well. Would you say what you see as a problem in this?

Mike
 
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I don't know that a person needs homogeneous to make a damascus tougher. Tougher would come from tempering a little softer as well as the nickel.

The nickel won't move at all, really. Should be the % of the billet made from high nickel steel will change the general toughness of the composite from the nickel aspect. The fact the carbon will equally diffuse (like a 50/50mix of 1.00% C W2 and 0.75% C 15N20 = 0.875% C) will, in an of itself, cause it to be tougher... less carbon, less brittle. In welding, the amount of time at high temperature causes nearly equal carbon diffusion.

Mike
 
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Substitutional alloy atoms diffuse at glacial rates compared to carbon. Think about it, otherwise there would be no contrast in the layers. Of course when things get out of hand in the making of the Damascus one can get fuzzy layers from this type of action.

My testing and experience shows exactly what logic would predict, that mixing an impact tough steel with a higher hardness more brittle steel will result in greater toughness for but no where near as much as the original parent steel. This idea of soft, or ever tough, layers between brittle steel in anything more than a san mai type laminate is pretty much myth perpetuated by little testing for confirmation. My testing shows a slight slow down of crack propagation but nothing stopping it. Even with layers of materials that should be dead soft exhibiting brittle cleavage type fracture instead of heavy slip shear type. This is after all the distinguishing characteristic of impact load versus gradual bending, under impact the shear slip and twinning actions cannot keep up with the load rate. The brittle layers begin the fracturing action which still manages to spread through the surrounding material to the next point of fracture in the the subsequent layers. As has been stated, greater toughness can be gained by an overall lowering of hardness but at a necessary loss of strength. So mixing 1018 with O1 will indeed produce a tougher blade but not because of tougher reinforcing layers but because of a greater softness of the steel as a whole, rendering the once great edge holding O1 to a medium carbon steel at best.

Of course I too am a great advocate of mixing oil hardening steels with oil hardening steels, and water hardeners with water hardeners, due to the obvious compromises necessitated. Not only in final performance but in the distortion issues presented. The smith who ignores the ideas of hard/soft layers in favor of abrasion resistant-strong/tough layers will reap the benefits of higher hardness, better edge holding and edge stability in a tougher blade than they would have otherwise had.

15n20 will work fantastically with 1095, 1084, 1080, 1075, W1 or W2. L6 is better suited for O1, O2 and other oil hardening alloys. The 8670M is on the border line and can be combined with moderate safety with either, but will probably match up better with oil hardeners.
 
We have found a stash of L6!(no big deal) or: are there better options 9 years later? Same Toughness better price easier to work steel formulations??????? reviving this thread! we will be using for Monolithic Axe head. Blessings and aloha
 
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