why is 1050, 1060, 1075 etc. shallow hardening?

[30cal_Fun]

Hi,

People have been using plain carbon steels like 1050, 1060, 1075 and others with great success in the past decades in making Japanese style blades. These steels have a solid reputation for creating a good Hamon. They are shallow hardening, it is not hard to create a Hamon, and if done well, the Hamon will be readily visible and with lots of activity.
The 1075 Katana's made by people like Rick Barrett and Anthony Dicristofano are well known for there tough blades and beautiful Hamons.
When you look at some typical analysis of the properties of these steels, you can see they have A LOT of manganese and sometimes they even have a bit of chromium (however, the chromium is usually not that high);

1050: 0.50% C, 0.25% Si, 0.75% Mn, max 0,04% P, max 0,05% S.

1060: 0.60% C, 0.25% Si, 0.75% Mn, max 0,04% P, max 0,05% S.

1075: 0.75% C, 0.25% Si, 0.75% Mn, max 0,04% P, max 0,05% S.

However, seeing these typical analysis, how can these high levels of Manganese still make it shallow hardening?!?
Pretty much everyone knows that these steels have high manganese levels, but my chemistry is not good enough to explain why it is still suitable for creating a good Hamon.

So, why is it that these steels are shallow hardening? (and therefore good for creating a Hamon)

Louis

[pkrankow]

How about you look at the chemistry for some deep hardening tool steels like O and A series?

The iron will form austenite and the alloy elements will help retain martensite upon quench. The alloying elements help prevent the molecules from shifting from one crystal arrangement to another, which is why a long soak at temperature is specified for tool steels.

Shallow hardening steels retain martensite in areas that cooled fast enough and were not brought back above tempering temperature. The rest reverts back to cementite. The low amount of alloying elements allow the crystal structure to shift quickly, so long soak times at temperature are not necessary.

Hope this helps.

Phil

[30cal_Fun]

Thanks for your explanation, I kind of understood what makes steels of the O and A series deep hardening, but now I understand better how it works.
However, I can't really follow why these steels are still shallow hardening instead of deep hardening. You say that "The low amount of alloying elements allow the crystal structure to shift quickly" but the manganese levels seem high enough to make the steel deep hardening. If this amount doesn't make it deep hardening, above what level of manganese content WILL the steel become medium- and deep- hardening?

Louis

[pkrankow]

http://www.sousacorp.com/ts-comp.htm
Looks like O2 has 1.6%Mn and .90%C.

I am not a material scientist so we are at the limit of my knowledge too.

Phil

[30cal_Fun]

oke, thanks for you input.
I hope someone can explain it further to me.

Louis

[30cal_Fun]

Since no one seems to be able to answer this question I hope you can help me with a different one:

At a suppliers website I found the following steels:
1.1520 C 70 W 1
1.1525 C 80 W 1
1.1530 C 85 W 1
1.1545 C 105 W 1

1.1620 C 70 W 2
1.1625 C 80 W 2
1.1630 C 85 W 2
1.1645 C 105 W 2

I am pretty much sure that the C xx W 1 steels are AISI W1 but I didn't know that W1 could have different levels of carbon. Can W1 have this many different amounts of carbon?

My second question is:
Are the C xx W 2 steels AISI W2???

Louis

[Hamurra-e]

Hi,
my English is not that good so have mercy with me.

I think you look at German Steel and there the W1/W2 has another meaning.
I cant quit remember put i think it says how clean and close too tolerance it is.
By the way, this Steel are only shallow hardening when they are thicker. Over 15 mm ore thou. If you make a blade of say 10mm it will harden all the way threw.

[30cal_Fun]

Thanks Hamurra-e,

You are correct about that, C xx W 1 and C xx W 2 are the German names (The first ones are European Werkstofnummers). But when I google it, C80W1 and 105W1 both turn out to be W1. I got that information from Metal Ravne which seems like a very reliable source.
Here are the links:
C80W1
C105W1

That the C xx W 2 are AISI W2 is just a wild guess. As far as I know, AISI W1 has more tungsten (W) and AISI W2 has more vanadium (V)

Louis

[Hamurra-e]

Aha
but i cant see V ore T an the specs
thou W1 and W2 in the US can have any C between .8 and 1.0 ?
OK i gonna trey to find what the W1/W2 means in Germany
now i gotta know

[30cal_Fun]

The chemical designation for tungsten is actually the letter W (periodic table )

The links I gave already have the Din number (Deutsche Industrie Norm) and the Werkstofnummer in it.

Here are two other links from Diehl Steel of W1 and W2
W1
W2

I am pretty sure that the C xx W1 is actually AISI W1, but my knowledge ends there. Let me know if you find anything.

Louis

[Hamurra-e]

Ok hier it is
just as i remember

W = Werkzeugstahl
W1, W2, W3 = Werkzeugstahl 1. 2. und 3. Güte
WS = Werkzeugstahl für Sonderzwecke

can you read German?

it maens 1-3 Qualitie or first ist best

The steels you showd ar simbel Toolsteels without much extra.
thou C80w1 is a very clean C80 steel und also hast .80 C
weil normel c80 can have .75-maybe .90 C
but i think i can finde the German W1 and give you its DIN number

[30cal_Fun]

W = Werkzeugstahl
W1, W2, W3 = Werkzeugstahl 1. 2. und 3. Güte
WS = Werkzeugstahl für Sonderzwecke

it maens 1-3 Qualitie or first ist best

Danke schön! My German is not so good, but this I can understand just fine. I didn't know that, thanks for the information.

Weiß du eine gute Stahlhandel im Deutschland?
I am trying to find good steel like CK50, CK75, CK80, CK85 or CK95 or if I can find it: C70W1, C80W1, C85W1, C90W1, C100W1 or C105W1. These steels would be ideal for making Japanese style blades. In the Netherlands it is pretty much impossible to get good blade steel for making a Hamon.
So far, outside of the Netherlands, I have tried Pauly Stahlhandel, Stahl Becker, and Messenmacherbedarf. The last one has CK60, but it has a lot of manganese and I am trying to find something else with less manganese (manganese is not good for creating a Hamon).
BTW: I often see Cxx and CKxx as separate steels (like: C75 / CK75 ). Are these different steels/qualities or just different names?

If you know a steel supplier in Germany that can sell me good steel, please let me know.

Louis

[Hamurra-e]

Sorry,
I don't buy Steel, i'm a take it were it cams from guy
But you can have a look here http://www.messerforum.net/ there must be a topic about were to get Steel. Just cut not find it.
You may also ask for the german W1 cors i dint find it yet.
hey your German i not bad.

[30cal_Fun]

Thanks for the tip,
I saw the forum a couple of times, it might be a good idea to post a question there.

Louis

[thingmaker3]

So, why is it that these steels are shallow hardening? (and therefore good for creating a Hamon)

Louis

It's all about carbon moving around in the steel. If there are few or no alloying elements other than iron and carbon, then the carbon can more quickly form cementite. The more things we put in the way, the longer it takes for the carbon to form cementite. If the carbon does not have time to move around and form cementite, it gets caught in the interstitial spaces of the iron lattice - viola! Martensite!

For a more eloquent and more detailed explanation, read "Principles of Heat Treatment of Steel" by George Krauss, "Principles of Heat Treatment" by Grossman and Bain, or "Tool Steel Simplified" by Palmer and Luerssen.

[30cal_Fun]

thanks for the info, I am starting to get a picture of why steels can be shallow or deep hardening.

but my question was; why is it that EVEN WITH THIS MUCH manganese, these steels are STILL considered to be shallow hardening?
because with all this manganese, my knowledge would tell me this steel is deep hardening.

[Steve Sells]

thanks for the info, I am starting to get a picture of why steels can be shallow or deep hardening.

but my question was; why is it that EVEN WITH THIS MUCH manganese, these steels are STILL considered to be shallow hardening?
because with all this manganese, my knowledge would tell me this steel is deep hardening.

less than 1% is not that much Mn really

[30cal_Fun]

less than 1% is not that much Mn really

As far as my knowledge stretches, I thought that 0,4% manganese will make a low alloyed steel like this about medium hardening, and when it goes over 0,8% it becomes deep hardening. Springsteels often have about 1% manganese and they are deep hardening.
Do you mean that even with, lets say, 0,6% manganese it will still be shallow hardening? (presuming the steel doesn't have much other significant elements)

Louis

[Hamurra-e]

Hi their,
yoop 1% isn't much,in the most spring steels Si ore Cr are the sinners when it cams to deep hardening. Si can make it even Air hardening and it doesn't take that much of it.
If nice Hamons is all you wont, than the German steels you fount work well. With practice that is ;)

[30cal_Fun]

Hi their,
yoop 1% isn't much,in the most spring steels Si ore Cr are the sinners when it cams to deep hardening. Si can make it even Air hardening and it doesn't take that much of it.
If nice Hamons is all you wont, than the German steels you fount work well. With practice that is

I didn't know that ,
I always thought that manganese was the real Hamon-killer, almost as much as chromium...
I did know that even 0,40% chromium can keep you from getting a Hamon, but I didn't know that manganese had THAT LITTLE effect on a Hamon.
If manganese doesn't change the hardening that much, finding good steel has suddenly become A LOT easier.

Am I right then in assuming that 0.60%-0.90% manganese will still get me a good Hamon?!?

Does anyone know a good website or book where all the effects of alloy elements in carbonsteel are explained?

[pkrankow]

http://mydocs.epri.com/docs/public/000000000001014670.pdf
just found this
Phil

[30cal_Fun]

http://mydocs.epri.com/docs/public/000000000001014670.pdf
just found this
Phil

I just looked at it, it has some good information about what elements do in steel, but not how the hardening responds to that. Thanks non the less, I have it saved.

[Hamurra-e]

Hi,
have a look at this side
http://forums.dfoggknives.com/index.php?showforum=3
here you will find a lot about hamon and steel and the Forum has lots of Bladesmithing and Knivemaking
Look also for Verhoefen he wrought a lot about hardening of Knife steel,thare must be an dread to it.

[30cal_Fun]

oke, I will look trough it more.
I did already, but couldn't find exactly what I was looking at first.

[Hamurra-e]

Husaaa
now i found it W1 is the German steel 1.1545
has a lot C around 1.0

1.1545
Chemical composition in weight %: 1.03% C, 0.17% Si, 0.22% Mn, 0.014% P, 0.012% S, 0.07% Cr,
0.01% Mo, 0.10% Ni, 0.14% V.
Note: Tool steels, unalloyed. Austenitizing temperature: 790 oC.
Source: HTDG, 2008.