Anyone else find 1084 prone to warp?

R

ricky_arthur

Joined
Jan 4, 2013
Messages
217
I have 5 smaller knives in the works and 2 of them I promised to have ready for Valentines day. So I got all 5 ready for heat treat. Did 3 normalization cycles. Quenched the first one, no problems. Quenched the second (the only one that was Hollow ground) And it warped all to heck. I threw it back in the forge to anneal it and got the 3rd ready. It was the largest of the 5. It warped too. :eek: Since both were promised by tomorrow, I couldn't risk breaking them by straightening them after quench. So I annealed both and re quenched. The larger one came out good, the hollow ground one warped again only not quite as bad. I decided to temper them all and see if I could straighten it after tempering.

So after temper I took them all to the shed to clean them up. I noticed one of the others had a very slight curve right in the center between the blade and handle. I walked over to the anvil and tap, tap, tap. Nothing, tap, tap tap...Nothing

TAP!
5021522E-BD1C-4E5D-9B3B-5C341BF4A8B2-762-00000075AEAC1BD9_zps76b09d05.jpg

Danggit!

I know everyone loves 1084, but I never had a small to medium sized 1095 blade warp on me, I'm about to switch back. :( At least 1 out of 3 with the 1084 will warp. Even small ones.

anyway, I decided it was a good opportunity to check grain size and so I cut it in half, and was pleasantly surprised. A pic is hard to see because the light makes it look funny but in person the grain is small enough that it is hard to see grain with the naked eye.


I was wondering how The grain would look using my heat treat method and now I know. I guess it was worth throwing about 3 hours of work in the garbage.
 
I just had a 1084 blade edge warp on me about an hour ago, but it was my own fault because i took the edge down too thin before HT. It only warped very slightly and just in the about a half inch long by quarter inch high spot, (the thinnest on the edge i guess). I have however had some blow up when i tried a brine quench. My thought on that cracked one is that it likeley didnt temper back far enough and stayed fairly brittle.
 
Grayzer86 said:
I just had a 1084 blade edge warp on me about an hour ago, but it was my own fault because i took the edge down too thin before HT. It only warped very slightly and just in the about a half inch long by quarter inch high spot, (the thinnest on the edge i guess). I have however had some blow up when i tried a brine quench. My thought on that cracked one is that it likeley didnt temper back far enough and stayed fairly brittle.
Click to expand...


Possible, but It went thru two, 2 hours tempers at 390 and 400deg
 
My first kinfe(only knife) I left the edge like 3/32 thick! How thin do you guys usually take your blades before quench?
 
sintro said:
My first kinfe(only knife) I left the edge like 3/32 thick! How thin do you guys usually take your blades before quench?
Click to expand...

I take mine down to just under the thickness of a dime. Then after heat treat, take it down a little more. It depends on how prominent I want the secondary bevel to be.
 
Are you laying it on its side in the kiln or in a fixture spine down? That is the number one cause of warp I have seen

-Page
 
laying it flat down is a cause of warping because one side get hotter. another cause is uneven grinding. if you hollow grind and one side is higher than the other could cause warpage. try to keep the thickness to no smaller than a dime before HT.
 
I have seen warp from laying blades on their side almost every time someone says they have warp problems, one guy had them on their side then he would pick them up by lifting the tang while the point was on the kiln floorwhich would put an inch bend in a blade. That was a Doh! moment when I pointed out what I had just watched him do. I have a fixture I made for holding a blade 1/4 inch off the bottom of my kiln spine down edge up that is easy to pull the blade up and out of without touching anything on the way out.

-Page
 
I heat treat in a forge. I lean the blade on the forge wall on the left. As it heats I move it to the right side. Then before I quench I pick it up with the tongs and pass it through the heat on both sides to make sure it is evenly and completely to temp. Same practice I used when I was using 1095 and I wasn't having a problem with warping.
 
A fair number of my 1084 knives get warped during HT. I've started using Rick's method of straightening them during temper and it's miraculous. Barring that, I heat to 400º and bend in my vice. I've only broken two blades in the last year and a half.

- Chris
 
I haven't seen any more tendency to warp in 1084 than with most other oil-quenching steels. Even forging and grinding, even and reasonable edge thickness, good normalizing/stress relieving, even heat during austenizing, and proper quenching techniques will minimize warpage...but you will still have blades warp on you.

I don't think you should ever compromise your technique in order to maintain a delivery date. You said that you couldn't risk breaking them by straightening out of the quench...it broke anyway. I would never try to straighten a hardened blade with impact force, fixture tempering or careful spot work with a torch and 3-point jig are the only options I would use, short of re-heat treating. The torch and 3-point jig requires a lot of practice, I still don't trust myself to do it without creating soft spots in the blade but I would recommend it over cold straightening or hammering any day.
 
ricky_arthur said:
I heat treat in a forge. I lean the blade on the forge wall on the left. As it heats I move it to the right side. Then before I quench I pick it up with the tongs and pass it through the heat on both sides to make sure it is evenly and completely to temp. Same practice I used when I was using 1095 and I wasn't having a problem with warping.
Click to expand...

looking at your picture you burned that one now that I'm looking at it on something bigger than a phone. When you get it that hot leaning against the side of the forge it is going to want to droop slightly then when you lean it against the other side while soft it will bend infinitessimally when you make contact on that side. I use an electric kiln and heat 1084 to an indicated 1495 for 20 minutes after the kiln has equilibrated for an hour and have had one blade warp noticeably in 12 years and that was because I bumped the fixture on the way out

-Page
 
This is off topic, but that sharp triangular jimping, as good as it may look, is a huge stress riser. On topic: No, I have not. Even with my torch + magnet HT.
 
It looks like you got it too hot. Any leaning at HT'g temperatures will likely induce warp. My suggestion is to keep the blade moving the entire time. It won't take long to come to temp. If you are using a propane forge with the burner coming in from the top, heat it with the edge down until it gets close to nonmagnetic. Then switch to edge up and pump it through, being careful not to bump it or pause too long. Quench edge up and be sure to agitate. Never try to straighten a warped blade by hammering it on an anvil. Either clamp it during the temper or use a 3-point straighteing jig. either way, make sure to straighten while the blade is hot.

I also think your filing on the spine is too sharp... same goes for that spanish notch.
 
Hesparus,

In one of your posts you wrote "I've started using Rick's method of straightening them (blades) during temper and it's miraculous.". I'm new to this. Can you explain Rick's method for me or send me the URL where I can find this info? I'm just starting out making blades and would like to know how to fix warpage when it happens.

Please feel free to email me at schwatk@yahoo.com

Thanks for any and all help!

Joe
 
When the blade went into the quench, how deep did it go. It looks like it was submerged to thee end of the loop. If thats true, theres a good chance of a stress riser at this point. The submerged steel is cooling very fast while the steel above the oil is resisting the change. That creates big problems especially if there are holes or slots in the blade.
 
Last edited:
You must log in or register to reply here.
Back
Top