Hardened 1080 bar stock

L

lonepine

Joined
May 7, 2010
Messages
902
I'm feeling pretty discouraged and frustrated tonight. This subject has been brought up before but I want to explore it a little more for the sake of my personal sanity. (Yea, I know, too late for that!)

The problem
I bought some 1080 steel from one of the popular steel suppliers to the forum. When I tried to use my hacksaw to cut it I could only cut a little way and then nothing. When I tried to drill holes in it the bits would go just a little way into the surface and then they stopped penetrating. It seems as if there is an outside layer of soft metal and an inner core or hardened steel. My best guess is that perhaps it was cold rolled and became work hardened. Can someone please tell me what is causing this frustrating situation?

Solutions
Previous solutions included “Buy a high tension hacksaw”. I bought one. It does work better than a regular hacksaw and I’m glad I have it. (Can’t have to many toys, er, I mean tools) Unfortunately I had no better luck at cutting the 1080 with it than I did with my old “low tension” hacksaw.

Another solution was to use carbide drill bits when I need to make holes in it. I see that Jantz sells them starting at $12 for a SINGLE BIT! OUCH! Most of the bits are $14 - $16 per bit. But the 1/4 “ bit is going for $30. I was at our local Fleet Farm store today and though they carry lots of tools they did not have carbide drill bits. I need to look around some more and see if I can find good bits for a reasonable price.

A third solution was to anneal it by bringing it up to a certain temperature and then slowly cool it by just leaving it in the kiln/oven. If I had an electric kiln/oven that is what I would do, but it seems a little excessive to have to spend $1,000 to anneal $100 worth of steel.

Non-solutions
Soooooo I was thinking,… What if I experimented and put a piece of the steel in my kitchen oven and just let it sit there in the back where no one will mess with it, and let it go through multiple tempering sessions? After sitting in there for about a month it emerged with interesting oxidation colors on it but I still could not cut nor drill it. There was no significant change.

OK, no more Mr. Nice Guy. Out came the propane torch. As I heated the steel I saw a dark blue color appear on the cleaned surfaces but I kept on heating it, and the dark blue went away. For some reason this seemed significant to me and I stopped heating the steel when the dark blue disappeared and I let the steel air-cool. I was pretty confident that this would work. Nope. Shot down again! Maybe it was a little bit softer, but not much.

My next plan is to treat it like softening an old file. I will build a fire, heat the steel in it and let the fire die down slowly with the steel remaining buried in the ashes to slowly cool. At this point I’m having doubts that this will work, given the string of failures I’ve had so far.

Summary
I feel very discouraged and frustrated. I’m not trying for fully shperodized or annealed steel, just soft enough to be able to work it with NORMAL tools. Is this unreasonable of me to expect? If I were tooling special aerospace materials for critical applications it would be one thing. I just want to make some knives. What Have I done wrong? What else can I try?

I feel very discouraged and frustrated. Am I going to have to jump through these same hoops every time I get steel? This is going to turn into expensive steel if I have to take it somewhere for annealing. Is there NOTHING that can be done without a kiln?

Did I mention that I feel very discouraged and frustrated?

"Help me Obiwan, You're my only hope!"

Yours in frustration,

- LonePine
Alias Paul Meske, Wisconsin
 
Obi-wan here,
If you can bring it up to temp with your torch, just bury it in some pearlite or vermaculite. I have a 5 gallon bucket of pearlite I bought at home depot and it works well. Try to get the entire blank glowing and just shove it under the pearlite and let it sit overnight. It should anneal it for you.

Also, I cut out about my first 100 knives with an angle grinder and cut off wheels. I would get the basic design cut out and then grind off the left-overs with the 4x36 I was using back then.

Also again, for drilling make sure your drill press is running at a slow speed and use some actual cutting fluid for it. You can pick it up at most hardware stores, or if you know someone in a machine shop, that might help too. I have done the whole WD40 thing and actual cutting fluid works 100 times better.

hope this helps, paduan :)
 
All ya need to do is normalize it. Bring it up to critical temp (1450-1599f) (non-magnetic) and let it air cool. Use forge, torch, etc. You have to be able to hit critical temp anyway to heat treat, might as well get set up to do it.
 
Yup you got some hot rolled as rolled. If at all possible you should try to get hot rolled annealed or cold rolled annealed. If you are a stock removal maker the later is best. Follow Don's suggestion and you will do fine.
 
Quote: “Obi-wan here,
If you can bring it up to temp with your torch, just bury it in some pearlite or vermaculite. I have a 5 gallon bucket of pearlite I bought at home depot and it works well. Try to get the entire blank glowing and just shove it under the pearlite and let it sit overnight. It should anneal it for you.

Also, I cut out about my first 100 knives with an angle grinder and cut off wheels. I would get the basic design cut out and then grind off the left-overs with the 4x36 I was using back then.

Also again, for drilling make sure your drill press is running at a slow speed and use some actual cutting fluid for it. You can pick it up at most hardware stores, or if you know someone in a machine shop, that might help too. I have done the whole WD40 thing and actual cutting fluid works 100 times better.

hope this helps, paduan”

Thank you Master. You enlighten me. No longer will I have to cut my padwan braid. I must get to my land speeder and head on over to a local retail establishment that sells the miracle materials of pearlite or vermiculite. Then I will have to construct a one or two brick forge and get a couple tanks of propane.

I have been able to rough cut some blanks from this steel with an angle grinder and hard-wheel grinder but it seems senseless to have to go through so much extra work. I am not the world’s best knife maker. Quite the opposite, and anything that makes it more difficult to do good work does not help matters. I don’t have a problem working annealed steel; it’s just this particular shipment with the hardened center. Cutting out blanks is such a sucky job to begin with.

I’ve never used cutting fluid but will get some. Should this be used whenever I drill steel or just when it’s difficult to drill?

I don’t know what speed my drill is running at. I can change the speed by moving the belt to different sized pulleys though. Are you supposed to run smaller bits at faster speeds than large bits?


Quote: “All ya need to do is normalize it. Bring it up to critical temp (1450-1599f) (non-magnetic) and let it air cool. Use forge, torch, etc. You have to be able to hit critical temp anyway to heat treat, might as well get set up to do it.”

I’ve wanted to make a one or two brick forge so maybe this will be the justification I need to get off my butt and do it.


Quote: “ Yup you got some hot rolled as rolled. If at all possible you should try to get hot rolled annealed or cold rolled annealed. If you are a stock removal maker the later is best. Follow Don's suggestion and you will do fine.”

This has certainly been a learning experience for me. Good thing I have excellent teachers to help me through it. Thanks a million guys. You’ve saved me thousands of dollars that would have gone toward years of intensive psychotherapy, and I won’t have to cut my Padwan braid. I just wish I would have known before I bought it that I was going to have to deal with this.

- LonePine
Alias Padwan Paul Meske, Earth
 
Always,always use cutting fluid when drilling,your bits will last twice as long.
Stan
 
I'm resurrecting this thread for this important (to me) update.

I've gotten some pearlite to put annealing steel in but haven't yet found a suitable metal container to put it. However, I've arrived at a stop-gap measure that gets me by. See the picture below please.

P1070003L.jpg


My tempering oven has burners on top!!! I always wondered what they were for. Using the largest burner I turn it on high and set the rogue steel on it. I leave it on for five or fifteen minutes and flip it in case it makes a difference, and let it sit again for five to fifteen minutes, then turn the burner off and let it and the steel cool down slowly. It takes glass topped stoves quite a while to cool off.

If I start off with relatively "bright" steel, i.e. no slag coating, it ultimately turns really dark after going through the rainbow of colors that it normally does and can be seen where the steel transitions from being on the burner to being off the burner.

It is a bear to cut with a hacksaw but at least it cuts it, not skate off it like it did before. And now I can drill holes in it, using cutting fluid of course. It makes a crackling sound when drilling it though.

I'm not sure what's happening to the steel since it's not anywhere near the temp needed for annealing, so I pretend that it is tempering it, a LOT.

- Paul Meske
 
Paul,

I found the same thing with the 1080 hot rolled that I've been using lately. It's frustrating to work with. I did find that if I take an orbital sander to the surface to remove the mill scale, it works a little better. I've also been using an abrasive blade in my hack saw. It's basically a thin wire cable embedded with carbide chips. It's painfully slow, but since I don't have a bandsaw yet, it's better than nothing.

Nathan
 
Do you have a charcoal grill? Use it to "anneal" (not a true anneal, but will soften) the steel, Just get the coals hot, nestle the steel in the coals and watch it get hot, when it's red (not blue, gray, black), take it out (use long needle nose pliers) and bury it in the vermiculite to cool. Really don't need to do the vermiculite thing with 1080 series, it will noralize and soften quite well if you just leave it in the coals until they burn out.
Since you have it you can put the verm. in any reasonable container, even a plastic bucket, just don't push the steel to the bottom (and out). I used an old discarded ice chest for a long time.

Note:If you don't have a grill just dig a pit in the yard and fire up the charcoal...it'll still work.
 
Carbide tipped masonry bits are cheaper and far more available and the tip tends not to skid so much.

PS. Set drill to slow.
 
Yup if you are a stock remover and just need to soften the odd bar of steel, a pit(or brick hearth) and some hardwood lump coal will get it done. But if you have the slightest inkling to make a forge and eventually hammer/heat treat your own blades, go for it. You can build a decent LP forge very cheap and it will save you money in the longrun.
 
Here is a metallurgical quick fix.

Heat the steel bar to red color with a torch or stove burner. Check it with a magnet to assure that it is not magnetic any more. Don't heat any more than needed to be completely non-magnetic. Remove from the flame and check with the magnet. When it becomes magnetic again ( in a few seconds), place the bar in the kitchen oven set at 450F-500F. Leave there for 30 minutes and then turn off oven and let sit overnight without opening. The bar shoulld be pure pearlite.

The metallurgy of the above is:
Heat the steel above critical (about 1350F) where the steel became austenite
Allowed it to drop into the pearlite range ( about 1000F), and then moved it into an environment above the Ms ( above 450F)
This prevents the formation of any martensite, and fosters the formation of pearlite.
The final structure should be a mixture of fine and coarse pearlite...mostly fine.
 
Last edited:
bladsmth said:
What you did was:
Heat the steel above critical (about 1350F) where the steel became austenite
You allowed it to drop into the pearlite range ( about 1000F), and then you moved it into an environment above the Ms ( above 450F)
This prevented the formation of any martensite, and fostered the formation of pearlite.
The final structure should be a mixture of fine and coarse pearlite...mostly fine.
Click to expand...

Stacy.... lol.... excellent solution..... it's just this perfectly mirrors my entire teenage dating experience. I almost became a monk.
 
bladsmth said:
Here is a metallurgical quick fix.

Heat the steel bar to red color with a torch or stove burner. Check it with a magnet to assure that it is not magnetic any more. Don't heat any more than needed to be completely non-magnetic. Remove from the flame and check with the magnet. When it becomes magnetic again ( in a few seconds), place the bar in the kitchen oven set at 450F-500F. Leave there for 30 minutes and then turn off oven and let sit overnight without opening. The bar shoulld be pure pearlite.

The metallurgy of the above is:
Heat the steel above critical (about 1350F) where the steel became austenite
Allowed it to drop into the pearlite range ( about 1000F), and then moved it into an environment above the Ms ( above 450F)
This prevents the formation of any martensite, and fosters the formation of pearlite.
The final structure should be a mixture of fine and coarse pearlite...mostly fine.
Click to expand...

So, Out of the fire and into the frying pan, so to speak. Thank you for this tip. I had heated the steel red hot (maybe not non-magnetic though) before and it still ended up being impossible to cut or drill with ordinary tools. Perhaps it had not gotten hot enough or it air cooled fast enough to harden again. Again, I appreciate the help and information.

- Paul Meske
 
NStricker said:
Paul,

I found the same thing with the 1080 hot rolled that I've been using lately. It's frustrating to work with. I did find that if I take an orbital sander to the surface to remove the mill scale, it works a little better. I've also been using an abrasive blade in my hack saw. It's basically a thin wire cable embedded with carbide chips. It's painfully slow, but since I don't have a bandsaw yet, it's better than nothing.

Nathan
Click to expand...

You seem to be experiencing exactly what I am, and yes, it is very frustrating. I've removed the scale but that didn't help. I have a similar carbide blade in my high tension hack saw. Painfully slow is a good description but at least it's progress. I doubt that a band saw would cut any better than a regular hack saw blade and I'll bet band saw blades are considerably more expensive than hack saw blades. Non the less, I hope to some day get a band saw.

- Paul Meske
 
crex said:
Do you have a charcoal grill? Use it to "anneal" (not a true anneal, but will soften) the steel, Just get the coals hot, nestle the steel in the coals and watch it get hot, when it's red (not blue, gray, black), take it out (use long needle nose pliers) and bury it in the vermiculite to cool. Really don't need to do the vermiculite thing with 1080 series, it will noralize and soften quite well if you just leave it in the coals until they burn out.
Since you have it you can put the verm. in any reasonable container, even a plastic bucket, just don't push the steel to the bottom (and out). I used an old discarded ice chest for a long time.
Click to expand...

I built a fire and put the steel in with the burning wood and let it all cool over night. No luck. You must have some really BIG fires. Mine probably didn't get the steel hot enough, certainly not red hot.

You know, I do have a small plastic ice chest that I could dedicate to this. I have perlite rather than vermiculite but I think it will serve the same purpose.


crex said:
Note:If you don't have a grill just dig a pit in the yard and fire up the charcoal...it'll still work.
Click to expand...

It's getting sort of cold outside now, would it be OK if just built the fire in my kitchen sink and turned on the vent over the "tempering oven"? ;-)

- Paul Meske
 
Paul,

I use a small metal trash can (with lid) to store my vermiculite. You don't have to worry about melting through the bottom when you shove the red hot steel in too far (but your steel will bend!!!). A band saw is on my equipment list too.

Nathan
 
What it sounds like to me is that you have lamelar pearlite (no not the expanded mica that you get at the garden store that you are using to slow cool your steel, but little flat carbides that have precipitated out of your steel because you are cooling it too slowly that will ruin hacksaw blades and drill bits)

I think the key to fixing your problem is that you need to do a speroidize anneal. Instead of heating up to Austentizing temp and then cooling extremely slowly which will precipitate large sheets of impenetrable carbides, you need to heat your steel up to just subcritical, cool it quickly, heat it a little less, cool it quickly, and cycle it a few more times, each time heating it to a lower temperature. That will break up the carbides and ball up the remnants so that they move out of the way of cutting tools instead of just destroying them.

_page
 
Lamelar pearlite,... Hmmm, something new. Just when I was sure I knew EVERYTHING! ;-)

- Paul Meske
 
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