Heat treating 1080 / 1084 / C80W2 steel

[30cal_Fun]

Hi everyone,

I recently bought C80W2, the steel arrived yesterday, here is the chemical analysis:
C 0,82%
Si 0,25%
Mn 0,22%
Mo --
V --
Cr 0,10%
Ni 0,05%
Cu 0,06%
W 0,01%
P 0,030% max
S 0,030% max

I have never worked with this steel before so I hope you can give me some tips about how to heat treat this steel. I intend to make several tanto with the steel and I will be claying it to form a hamon. This steel seemed ideal to make a hamon.
From the information I have gathered this seems like a good heat treatment:

Normalize 2 times by heating to 820 Celcius (1510F), taking it out of the fire, cool till black color, heat up to 820 again, cool to room temperature.
Clay the blade, clay thickness will be about 5mm (1/5 inch).
Heat to 780 Celcius (1440F), soak for a few minutes, then quench in water.
Temper two times at 200 C (390 F) for one hour.

Let me know what you think about this. I am not sure about the normalizing.
Any feedback or tips are welcome.

Louis

[son_of_bluegrass]

I don't use 1080 and I haven't looked at a TTT diagram for it. But I don't know if 780 Celcius (1440F) is hot enough. I think 1500-1550 F (815 - 840 C) would be better before quenching. Aside from that I think what you plan should work.

ron

[thingmaker3]

780C would be hot enough only if the steel were heated very very slowly.

It is important to remember the phase diagram is isothermal. If we heat more quickly, the transformtion temperature increases. Eutectioid transformation temperature can be around 1600F when induction heating small sections.

I echo Son_Of_Bluegrass' suggestion. You might get away with as little as 800C.

[30cal_Fun]

Thanks for the tips.

If 780 turns out to be too low, I will try 800C. I always try to heat slowly.
The reason why I am starting at 780C (1440F) is because this steel is right around the eutectoid point. Therefore it requires the lowest temperature and shortest soak time of all blade-steels.
Howard Clark suggested 780C to me as a starting point because of these reasons.

So far I have changed to things: I am going to do 3 normalizing cycles, just to insure the grain is as small as possible. Better safe than sorry and it can't hurt the blade (if done properly of course). I will also temper at 175C (350F) at first and go to 200C only if necessary.

Kind regards, Louis

[Rich Hale]

The company that makes that steel should be able to provide all the information on heat treat. If it was mine I would not try water. I would use oil. But thats is just me.

[30cal_Fun]

The company that makes that steel should be able to provide all the information on heat treat. If it was mine I would not try water. I would use oil. But thats is just me.

By now I think I have a good idea of how to heat treat the steel. I try to keep it as traditional as possible, I know modern steel is far from tamahagane of orishigane, but nevertheless I will always use (luke- warm or warm) water. Water will give a more active hamon than oil.

Kind regards, Louis

[basher]

If Howard gave you a temp of 780 then go with that .
If you are unsure about austenising temp look for recolesence as the steel cools . Most simple steels will easily austenise at the low end (or lower) of there recommended hardening range it just needs a little longer soak.
getting the temp rite for differential hardening in oil or water can be a trial and error process and blade cross section, normalising temps and frequency and then austenising temp prior to quench play a part so does the type of water and water temp.not to mention clay.........
were you going for an interupted quench or full quench .
All the best Owen

[30cal_Fun]

Sorry for the late reply, I hadn't checked for a couple of days.

Since I haven't used the steel before I will do an interrupted quench.
Quench, count to five quickly (about 3 seconds), then pull it out, count to five quickly again, put it back in the water and keep it there till it is cool enough to touch.
Getting past the pearlite nose in this steel should take about one second, so this way it should have plenty time to get past the pearlite nose and still minimize the shock.
BTW: I always move the blade through the water from tip to tip during the quench.

Kind regards, Louis

[Silent]

Hi There C85w2 , just for the Record is W1 Steel.

Has we know the W1 batchs Carbon contents may change from Mill to Mill.

It's good Stuff, The Closer from it you can get with Simple Carbon Steels is AISI 1084.(Wich is Very good Too)

You can Quench in Water or Oil, dependes what you want, if You are doing japanese Style Blades you Probably Should Water Quench. But still you can just Pre-Curve then Quench you will still get Good Hamon With C80 w2(W1 Tool Steel).

If i were you:
With 1084, w1 or W2 i Would do a Interrupted Quench like Water 3 Seconds , Then Mar-Quench into Hot Oil(350 F).

Regards

[sandpile]

During all the posts I did not see anyone mention a full anneal.
After the normalizing and before the quench heat. I like to do a full anneal
it helps on most of the warpage and sets the steel up for initial grinds.

Works for me.

chuck