finishing up a blade I made and running into some trouble with keeping the blade straight

steel: 1095

spine thickness: .07-.08 in

oil: parks 50

Quench temp: non-mag +4-8 seconds

oil temp: 6*C

doing best to move blade in up-down motion only 

on second try immediately after oil stops boiling placed between anvil and a large flat piece of steel, still bent. 3rd try same plus pushing on plate with my weight, not as bad but still some.

Now figuring I need reanneal and normalize again before trying any more

on the plus side the blade did come out hard (take half a win over a full loss)

 

results:  #3

 

TIA for any help

M.J.Lampert

I always normalize, then anneal. I follow the temps given in the specs that come from the manufacturer or "the heat treaters guide". Make sure the blade goes in point first and straight down. No sideways movement is critical. If this is what you are doing, then practice. 

For what its worth, I always quench my 1095 in water. 

That's interesting anvil, I've always been told to never quench 1095 in water. I usually use peanut oil heated to about 140° F.

If the 6 C oil temp is correct,  that might be part of the problem. People using Parks 50 recommend warming it to 120-140 degrees F. 

If you havent tried it, that warp might be fixed by clamping it to a thick bar with shims( like a 3 point straightening jig) and running it through a tempering cycle or two. 

6 degrees C is very cold, does not allow for much thermal circulation as it cools the metal due to viscosity

I wondered if that might be a typo, 60 C would be 140 F and more like it.

17 hours ago, Irondragon ForgeClay Works said:

I've always been told to never quench 1095 in water

Check the specs, 1095 is a water quench steel. Heat treaters guide, Uddaholm Steel, Carpenter Steel spec sheets. If you quench in oil, you highlight toughness over hardness. I'm pretty sure all of the 10 series steels are considered water quench. W1 and the 10 series have very similar characteristics and can be interchanged to save money without major characteristic changes.

I consider the 10 series steels to be a great all around steel. Make a hammer quench in oil to enhance toughness. Make a chisel, quench in water to enhance hardness.  

3 of my tenoning tools. All made from 1095, water quenched, drawn to a blue temper. The big one was made around 1984 or so.

I believe many bladesmiths do quench the 10 series in oil. This steel is more forgiving when oil quenched.

Water quench in thick sections, maybe, but I have never had good luck quenching thin sections of 1095 in water... it certainly won't help with warping.

If you can't get it to come out straight, double check your normalization cycle temperatures. Now that it's getting cold out make sure you aren't putting your hot blade on a cold surface to normalize. When it's cold out I will usually put the blade on top of my bucket of vermiculite (not buried, just laying on top), then I put the lid on .

If all else fails, take the warp out during tempering cycles with a 3 point bend.

Its not a matter of luck.   And nearly all, if not all, of my tempering is differential tempering, so that is, in my opinion, a great way to prevent warping.

Note the thick cross sections of your tooling above... I agree... The specs are generally given for a 1" cross section.

I, personally, based on my experience (which is less than yours) wouldn't recommend quenching a 1095 blade in water.

It is not advised to quench 1095 in water except for edge quenching.  There is a separate section for blades H/T because of the thin sections of blades resulting in different issues with hardening, it was explained in the heat treat sticky

Water versus oil versus commercial quench oils. Age old discussion amongst knife makers. Some advocate water, brine as their standard to good effect. Others use canola or peanut oil. And still others use commercial fast quenches.  I use parks 50 to good effect however the warpage  issue was strange. Steel I bought 1 hear ago didn't warp at quench. A small batch I got a couple months ago warped. Funny thing was someone posted an excerpt from the ASMI heat treaters guide/manual. It recommended water, however for 3/16 and under it recommended oil. Go figure! 

Boils down to what works best for you and the steels intended use.

Correct, Steve. the 10 series is more forgiving when oil quenched. Especially when done in an oven. If you do a differential quench on a blade, you maximize the properties of the steel. Thus less chance of failure.

Two tools made from 1095, water quenched, drawn to a purple for springiness. 

I present this not for the sake of argument, but to show just what you can do with this steel. It is very versatile and a great steel for any tool or blade. Know the characteristics and choose your process. 

What velgski said. 

Frazier, you do good work. Any recent projects?

 

16 hours ago, Irondragon ForgeClay Works said:

I wondered if that might be a typo, 60 C would be 140 F and more like it.

No, it's not a tempo I had heard that Parks 50 was good from above freezing to 160 so I figured to just make sure it was above freezing  i waited for a warm day (above -10C) to reduce the amount needed to heat it 

I might try to shim and clamp the blade when tempering if not i will start over again 

a good point i realized from Frazer was that my anvil and block of steel where cold so any remaining heat to help straighten would be drawn out as soon as they come in contact

M.J.Lampert

On 12/10/2022 at 11:19 PM, M.J.Lampert said:

spine thickness: .07-.08 in

Sure that is the spine thickness before quench, not the edge?  If so I'm surprised it didn't turn into a potato chip.  A spine between 1/8" and 1/4" thick will help with the bends, provided that you normalize and stress relieve before quenching.  My understanding of Parks 50 is that is operates best at ~room temperature  (i.e. 60-80 deg. F), and not only shouldn't be preheated too high, but that it will approach it's flashpoint of misused.  Fireballs with quenching are definitely to be avoided.

the average on the spine is .8 the edge is at about .3in 

 

Umm, now you are saying your spine is thicker than 3/4" and edge is over 1/4" thick?

ARG, fat fingers and a slow mind.

.08 and.03 respectivly

1 hour ago, M.J.Lampert said:

a good point i realized from Frazer was that my anvil and block of steel where cold so any remaining heat to help straighten would be drawn out as soon as they come in contact

A couple of 2x4s and some C-clamp vise grips might be worth a shot. However, take some of the other comments under advisement as well.

1 hour ago, anvil said:

Any recent projects?

I won't clutter up this thread, see my corner of the internet.

Now that we know you set the steel on an anvil cold enough to freeze water I'm surprised  the steel  survived the stress of that rapid a cooling change. The hot  expanded steel molecules started shrinking back to normal size in nanoseconds of hitting that freezing anvil surface. The side touching the cooler anvil had no choice but to shrink back  to size faster than the warm side, hence it warped. 

Better to clamp the tang in a vise than lay a warm or hot blade on a cooler anvil or steel table. 

Teaching in winter I try to demo a contact quench in  vise. Clamp a hot blade in and then open the vise, then open  and let the pieces fall to the ground...

Velegski : I hadn't thought of that because on both sides there were cold steel it would even out but thinking now there is a few seconds between the anvil side and the plate side cooling

i may take a few of your ideasuse some 2x4s warm them up, then use them in the vice to apply even clamping.

let me know if there would be any big problems with this

first things first though, wait for warmer weather

if i try shim the blade when tempering should i go till its straight or just past?

If it were me, I'd reheat it to a red or better, straighten the blade, then repeat your heat treat from the get go. At the very least its good practice  and would be better for your blade. 

I experiment. I use flat stock and clamp it flat for one tempering cycle. If I still have a slight bend then I use shims at one or both ends.