Grain in 1095?

Chiro75

Chiro75

Joined
Feb 4, 1999
Messages
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Until recently I've been a dedicated 1084 user. I switched to 1095 and I've noticed some differences. First of all, the banding that would show up frequently in my HR1084 is gone, which is nice, but the HR1095 I use has this little graininess too it when I etch it. I don't think it's bad, but it just doesn't seem to etch and finish up quite as nicely as I could get 1084 to. I'm not forging, just stock removal. I have seen the grain on ferric chloride etches from 400 grit to 1500 grit and it doesn't seem to matter. It's in the softer part of the blade, not the hardened edge. Any ideas, or is this just what 1095 does?
 
Yes, one cycle. Heat to non-magnetic, then air cool. Then coat, repeat, quench, immediately temper at 380°.
 
You'd really benefit from doing AT LEAST 3 cycles. I'd recommend more like 5 or 6.

-Nick-
 
Nick, 5-6 normalizing cycles or 5-6 tempering cycles? I assume you mean normalizing... Will get easier when I get my coffe can forge built. Of course when I'm ready to spend $$$ Ellis goes away for a couple weeks! :D
 
from what I understand normalising is bringing to a low dull red then cooling. Not to non magnetic.
 
Hmmmm. The knives are coming out okay despite if I'm making an error on normalizing, but I guess that would be a good thing to clear up. Time for a search!
 
Chiro75 said:
Hmmmm. The knives are coming out okay despite if I'm making an error on normalizing, but I guess that would be a good thing to clear up. Time for a search!
Click to expand...

Sounds like they might even be BETTER. I would listen to that Wheeler guy; he is a real fanatic about that heat treatin stuff. ;) :)
 
PLus he looks like a big muscle dude, so I would listen to him even if he was full of S! :D
 
The "ASTM Guidelines For the Heat treatment of Steel" calls out a normalizing temperature of 1550 °F for 1095 steel. Soak at temp long enough for homogenization (i.e long enough for complete austenization) and then rapid air cool to black heat.

IMHO getting steel to harden is easy. Doing the "Trifecta" consistantly is the hard part. Getting steel to harden while having the correct microstructure, and being properly tempered is what makes a big difference in the quality of a knife.

I normalize at 1650°, then at 1600°, and then at 1550° and then austenize at 1550°. I think it is critical to do it on all steels whether it is damascus or plain. HR sheet has been rolled at high temps and probably relatively low cooling rates or even annealed to make the working characteristics desireable. All that extra heat and time at temp would be likely to grow the grain structure.
 
Hey, Sean, that's great info but without molten salts and fancy schmancy digital control units, then what? Remember, we're talking caveman level knifemaking here! ;) In 5 years I haven't had a knife come back with any complaints, but as I make higher volume with big boy tools that could change (and I don't want it to change), so is it a matter of getting molten salts and stuff or can I fudge it with my handy magnet? Sheesh. Why's this so complicated? :D
 
I guess it all depends. I think the majority of makers out there don't use salt pots and make great knives. The salt pots allow for more reliability and repeatablility. There are makers that have spent days, weeks, months, and even years perfecting their HT methods to get the most out of thier blades. Like I said before, getting the steel to harden is relatively easy, but getting all the other factors to come in line at the same time is difficult.

Salt pots make it easier just because it takes the temperature variability (both actual temp and hot spots) and decarb/scale (as long as the pots are kept neutral) out of the equation.

You saw my salt pot set up when we heat treated your tanto. It is ugly and not fancy but functional. I built it for about $150. For that price it was well worth it for me.
 
I was going to ask you about the $$$ of yours. Hmmmmmmmmmm. Still need a metal-cutting bandsaw, and some toys, which is the whole darn reason I sell knives to begin with! :D I may be in touch about getting myself one of those things.
 
Chiro, I have had the same experience as yourself.

What is happening is you need to remember that the HR1095 is hot rolled (ie.- the "HR"). The steel doesn't come from the mill annealled. The grain you are seeing in the softer regions is sort of semi-hardened steel. I have been told it is like a bainite structure. When etched it produces an interesting texture in the hamon or temper line. You will also see it on some of the Ed Fowler / Bill Burker blades in the transition zones between the multiple quench lines because there is a wide variation in the grain development in that region.

As Nick Wheeler is suggesting, sometimes 1 normalising cycle is not enough to totally remove this effect. It disappears only after multiple normalising cycles. As Nick says, AT LEAST 3. I have found that it also disappears after a single full slow anneal. That does the trick.

I was so attracted to this type of grain for its appearance, that I have been able to partially reproduce it in the past by first full hardening the blade with a full quench, THEN, applying the clay and making the hamon on the edge portion. The portion above the hamon would still contain portions of the grain. I don't do it any more simply because it is a LOT of trouble and I was having problems with blade warpage. (BTW, I learnt this from Bailey Bradshaw here on the forums, so its not mine...) I am also likely to be wrong in some of my terminology, as I am a very inadequate metallurgist.

Just to be sure, is this the effect you are referring to ? Sorry the link is to a 350kB pic taken some time ago. Jason.

http://www.fototime.com/9B385A1EAD81005/orig.jpg
 
Jason, thanks for the information and picture. I took part of the pic and posted it, so I hope you don't mind...I think the part of the picture I cropped out shows what I have noticed with 1095, but not with 1084. I don't think I have seen the longer grain you've shown. It's more feathery, shorter grain like the area the arrows point to.
 

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I get stuff like this.....
doublegrind.jpg
 
Nope, I haven't seen anything like that. I think that looks pretty cool, actually. Is having that "flamed" look to the hamon bad?
 
You may get some different opinions about that but I dont think it is a bad thing at all.
 
It could be carbides that don't go all the way into solution. 1084 is a euctid(sp?) steel, meaning the amount of carbon in it is perfectly balanced and will all go into solution as soon as it hits critical. Since 1095 has extra carbon, it needs a slightly higher temp and a short amount of soak time to fully disolve the extra carbon. If you're not disolving it all then you have extra carbides floating around in there, which with light sanding and etching can become visible. I had one I did where I did lots of light sanding and etching, and it came out almost like wootz, really cool looking pattern, though technically it's not an optimal HT.
 
B Good:
It is obvious that by etching your blades you have become aware of the nature of the steel from what you see. The only way to know what you have is to test the knives fully yourself, edge flex, cut and full bends. Then combine the knowledge gained from each event and you will know without a doubt the qualities of your blades. No theory can help you, they are usefull only when we want to explore where we have been or sometimes where we want to go.
 
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