# Heat Treat Of 1045 Hot Rolled.  Recipe Review- 1st Time!



## countryguy (Jun 19, 2015)

Tada.... Time to actually put steel into the Refurbed Thermolyne furnace.   Below are the fast steps & specs and what I've found for the processes.  Could you take a look and maybe give me some pointers? 

Steel: 1045.  .25 hot rolled.  It is not annealed from the supplier.  Part is from a 4x8 .25 full sheet. 
Part: Plasma cut a part (sons tactical axe stuff) so it's a good size hunk of steel. 

HT info I found: 
A) Since it was plasma cut and the edges are technically now heat treated -vs- the body, I think I need to run a "normalize" phase first before I anneal it???   This is 870C to 920C degrees.  Heat to temp and then Let cool in still air.    Not sure on this one. 

B) once done, then run to the Annealing phase: Heat to 800C - 850C.  Let cool in Furnace.  
 (will check against the Rc tester between the HT and a non HT axe when it gets here next week also). 
C) Mill part. 
D) Run the harden phase: Heat to 820C-860C.  Quench in Oil or Water (I hear use salt water.  But What kind of Oil??). 

I'm really excited we are finally getting into this part of the project.   TIA
CG  / aka Jeff and Mitchell.


----------



## countryguy (Jun 19, 2015)

Crud... darn fingers!  Hot rolled.  Not hold rolled.  Cannot seem to edit the title post any longer?  Or I just do not know how.


----------



## jpfabricator (Jun 19, 2015)

From the "Modern Blacksmith" book. 
Quenching in water cools the steel the fastest, thus the core becomes a little less hard.
Quenching in brine the core is a little softer from slower cooling.
In oil ( 4 gallons of used motor oil in a metal container, with a lid for fire safety) the core is softer still.

Use water if the blade is thick.
Use brine if the blade i fairly thin.
Oil (or rendered fat) if the blade is very thin. End quote.
The book warnes that oil will flash, and leave a black sooted coating on the piece.


Sent from somewhere in East Texas Jake Parker


----------



## T Bredehoft (Jun 19, 2015)

Forget annealing it first, when you heat it to temp (glowing red hot, incandescent) dunk it in your salt water, swirl until uniform temp. 

I don't know about use as a knife, so i don't know what needs to be done to draw or temper the steel. For tooling I would heat to about 500 DegF and let it cool slowly, the slower the better.


----------



## countryguy (Jul 2, 2015)

Hey everyone-  Just some quick updates here on our learning of the HT processes for the Kids Axe making hobby.  We are going into this as  experimental and trial & error.   Making the omlet and breaking some eggs.  SO much fun.    I'll try to keep it brief:
Obtained evenheat KF27 oven.  OK quality and nice controls and feature/functionality over big names.  would buy again!
Reviewed and bought the HT book from Ray Cs HT post.  The "HT must read here on this forum for HT beginners".   Search it out.
We cut the kids axes with plasma CNC on 1045 hot rolled. It comes non-annealed.   They sell 4140 that is annealed at $4x the cost.

We also picked up a used HRc tester (import) from a local Mfr. here where I live.  The results were really neat.  We really enjoy getting data and watchin g results of our efforts.

Our first HR run was:
- Normalize per the instructions on this well known HT guide: https://books.google.com/books?id=boKzK-u2MoIC&lpg=PP1&ots=_KroGcNXqD&dq=heat treater's guide&pg=PA202#v=onepage&q&f=true
- Then went ahead and ran the Annealing instructions for 1045.
- The next morning after cooling off-  WOW... So soft.  I could bend the handle by hand.  Actually sagged in the HT furnace.
- Pulled up our newly learned DolphinCAD/CAM.  raced thru the setups and cut out his first real axe like cutting 1018.... good chip. Nice DOC and widths.  Now that is a huge improvement over whacking away at 1045 as-is.    The Hrc values were down to 7/7.5 on 3 samples after annealing.
Cons- Energy consumption.  WOW.... Long furnace runs for both and Annealing  & Normalize phase. I wonder if I can omit the Normalize part of the process down the road and just go w/ the annealing run?  we'll see.

Next steps:   He needs to finish his sanding and polishing on the steel and apply powder-coating.   Wood handle crafting.  (...now I guess he needs a small router...will it EVER end! ). 

Overall - We've been so busy making a shop and learning the basics, learning the math, the engineering, and of course how to run all this gear.  Everyone here has been such a great help!   thanks as always! 
Jeff and Mitchell.


----------



## countryguy (Jul 12, 2015)

UPDATE:  Our normalize, then anneal, machining went like a charm!    Again, this 1045 is so soft I can bent it by hand....  Peening it around is a breeze.  We did notice the handles warp a tad coming out of the oven,  but easily beat or bent back.  

Today-  We are ready to make our first heat treat and temper runs.   I have a brine mix setup i na 55Gal drum half full.  The Oven is cooking the project part now. 1100 now. Getitng close.  We have the Tongs, poke hook ,gloves and face shields ready.    A few hours from now we should be onto our first tempering run.  Learning these concepts is simply a lot of fun!  


*recipe: *
HT is heating to 1555F.  soak 10mins,  Pull and quech as fast as possible.  
Temper: A range of tempers following water soak exist.  
1050F for 620-860MPa     (So what's a  unit of MPA. .. . )  
895F for 860 -1035 MPa    (or 125 to 150 KPi) 
700F  for 1035 - 1175 MPA   

Not sure which tempering temp in F  to use.    Time to dig into the docs/books.


----------



## JimDawson (Jul 12, 2015)

Take a look here:  http://www.westyorkssteel.com/technical-information/hardness-conversion-chart/

It looks like there is an error in labeling the chart, the Rockwell C scale minimum is 20 which is correct, everything below that should be Rockwell B scale or A scale

M = 1000, Pa = Pascals


----------



## countryguy (Jul 12, 2015)

AhhhHa.  perfect.   My chart on the wall does have the KSI value.  I just needed to look up~   
Thanks Jim,  Thats the ref. I needed.  It all went just fine.  Ran 2 tests on the Axe.  54.5 HRc and a 55 Hrc.  The test block is 55HRc and we read 54.5  so I guess it all worked.  YAhoo...     time to temper her down a bit.       What I do not know is how long to let something cook for a temper.  checking that now.


----------



## countryguy (Jul 12, 2015)

For tempering:  Following some info here: http://smt.sandvik.com/en/products/...ing-guide/purpose-of-hardening-and-tempering/


----------



## countryguy (Jul 12, 2015)

OK-  Temper was done w/i about 1.5 hours @ 500F for 1.75 hours.  HRc value 42 -43.    Seems tough and resliant on the tree I was wacking around with. 
Thanks everyone here!  I will make a small plug- The Evenheat Kiln KF27 w/ ramp master is so easy to program.  I really, really like this furnace! 
CG out.


----------



## cdhknives (Jul 24, 2015)

Sorry I'm late to this...it's a favorite topic of mine.  Disclaimer:  I'm a hobby knifemaker and study heat treating a lot (about 20 years worth), but have only done a few torch to oil hardening blades and tools (non critical applications only) as the control and repeatability I require for high end blades is beyond such methods.  I send those to professional HT shops.

Generally there is no need to both normalize and then anneal.  Normalizing is a quicker way to get hard spots out (edges from plasma cutting, for example, and stresses from cold rolling) to a uniform medium soft.  A full anneal will be longer and go to dead soft, possibly too soft for some working.  Sagging of large sections is common in furnaces.  Get some soft firebrick, cut into small strips about 1" WxH, and support the metal every few inches.  Larger firebrick with slots cut in them can be used to stand the blades on end as well, which improves heating uniformity and speed.

Decarb will be an issue as every minute spent at high temp burns out some of your steel's carbon.  Look into stainless tool wrap if the scaling and decarb is problematic for your purposes.  Yes you can harden 10xx steels with tool wrap, but it's tricky.  Leave extra on the end that you can cut off with snips right out of the furnace, and drop from the foil into your quench.  Coatings are available to prevent decarb, but seem to be overkill for your current application (1045 steel).  Leaving a sacrificial outer layer to be finish ground is another strategy.

Any part of your 10xx steel that takes longer than about 1 second to go from 1550F (or so, varies a bit by exact metal composition) to below about 500F will not be full hard, hence the soft core in larger sections.  Study TTT curves till you understand this...

Test sections are a great learning tool.  Every time you HT, add a small strip of the same steel and test it after...bend in a vise, grind, sharpen and use, etc.


----------

