The riddle of steel

Cobalt

Cobalt

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So lets play a game. Lets see how many different grades of steel we can find that are similar enough who's property change is carbon to see how the mechanical properties change, specifically toughness? There is an end game to this, but I will put that out later, and it is a thesis of sorts. So I will start with two or three different steels.
First: 440C=1% carbon, 440B=0.8% Carbon, 440A=0.6% carbon and toughness increases as carbon goes down
Second: 1095= 0.95% Carbon, 1080=0.8% Carbon, 1060= 0.6% Carbon and toughness increases as carbon goes down.
Third: AUS10A, AUS8A, AUS6A the exact same thing happens there.

So you see how I am doing this.
So can you find any other steels that are similar enough, say they have the same chromium content(or close) but carbon changes and how toughness changes based on the carbon content?

Maybe break up the monotony of the usual threads we start a little.
 
So like CPM S30v, S90v, S110v? Don't know the break down but am I thinking on the right track?
 
I'm in...

This is easy....I THINK :confused::p

Aogami 2, Aogami 1, Aogami Super

or did you want smallest % of carbon last?:confused:

Thanks to Spyderco, or I wouldn't probably even know about these wonderful Hitachi steels!

*edit...

yup, just rechecked your initial post, just reverse my order...hahahaha:cool:

so how'd i do Professor Hog?;)
 
I'm a self-admitted piglet when it comes to INFI...:o

but I'm a wee, wee, wee piglet when it comes to steel analysis...:o:o

but one day maybe I'll grow to be a prize winning TOP HOG if I get fed enough...:D

threads like this is like throwing slop in my trough...:thumbup:

not saying your info is garbage, Cobalt...I mean its good for us piglets....uh.....er....YOU KNOW WHAT I MEAN!!! Anyways, THANKS!:rolleyes::p
 
PeteyTwoPointOne said:
I'm in...

This is easy....I THINK :confused::p

Aogami 2, Aogami 1, Aogami Super

or did you want smallest % of carbon last?:confused:

Thanks to Spyderco, or I wouldn't probably even know about these wonderful Hitachi steels!

*edit...

yup, just rechecked your initial post, just reverse my order...hahahaha:cool:

so how'd i do Professor Hog?;)
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Either way as long as you can find out if there are toughness values associated with those numbers


ALLHSS said:
1.45, 2.3, 2.8 respectively, I believe.
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and how does toughness go along with that? Does toughness increase as carbon content goes down? Which is what happens in the steels I posted and is what I am looking for.
 
Cobalt said:
Either way as long as you can find out if there are toughness values associated with those numbers




and how does toughness go along with that? Does toughness increase as carbon content goes down? Which is what happens in the steels I posted and is what I am looking for.
Click to expand...

I am nowhere near an expert, but I'd say yes, toughness correlates negatively with carbon content. However, I think because these are more alloyed steels than the 10xx, 440x, or Ausx steels the drop in toughness will be less relatively. Again, this is just general information I've gathered from light reading and on the forums, not to be taken as hard fact.
 
ALLHSS said:
I am nowhere near an expert, but I'd say yes, toughness correlates negatively with carbon content. However, I think because these are more alloyed steels than the 10xx, 440x, or Ausx steels the drop in toughness will be less relatively. Again, this is just general information I've gathered from light reading and on the forums, not to be taken as hard fact.
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I agree. I would say that with high alloy stainless steels you will see less a difference in toughness. However, the difference in toughness between 440C and 440A is very big. Just like the difference between 1095 and 1060.

In fact you can infer that the toughest steels almost always have around 0.5 to 0.6 Carbon. It seems like below 0.5 you don't gain much toughness and above 0.6 - 0.7 you loose it quickly. Look at two of the toughest shock steels available, S5 and S7, both have Carbon contents of around 0.5-0.6.

SR101 and 52100 both have 1% carbon and they can be tough because they can be differentially tempered to have a soft spine and hard edge which gives you a very tough knife. But if you thru harden them you will not have as tough a knife as you can get with less carbon. 5160 uses 0.6% Carbon and it is a very tough steel
 
I've read that H13 can be tougher than S7, and it runs between .35-.45% carbon, but it will only get into the low 50s HRC as a result.

I'm not sure how it compares in real world use to S5 or S7. I haven't found any higher carbon alloys of it, but it could be interesting.
 
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S5 and S7 have substantially different compositions from the sheets I'm reading.

S5

S7
 
As for H13, that is the kicker right. To low in carbon and you cannot get enough hardness to be worth anything for cutting
 
and guess what other steel has 0.6% Carbon?


Steel-----Hardness-----Charpy C Ft. Lbs.-----Carbon...............Cr

INFI ?? ...........................................0.5 to 0.6% C .........7.5%
Z-tuff..........@Rc58.........120 .................. 0.7%C...............7.5%
CPM-3V.......@Rc58..........85....................0.8%C................7.5%

So where do you think toughness of INFI stacks up? Of course this is not exact science because we are postulating. However, it is pretty obvious that INFI will exceed the other two. Interesting thing about Z-tuff is that it's formula is actually closer to INFI than 3V and it is almost 50% tougher than 3V at the same hardness. Even though we have no hard numbers for INFI we continue to get closer to the truth. There is no doubt that there is more to steel than just carbon content and it is the mix plus the ht that makes it all work, but carbon does have an effect on toughness in a negative way, that much is obvious. Then add in the best HT on the market and things get skewed even more ;)

here is the spec sheet on z-tuff. If you look at it's content and compare it to INFI you will see they are much closer to each other than 3V is to either of them.

https://www.zapp.com/fileadmin/downloads/01-Produkte/Tooling-Alloys/Z-Tuff-PM-Data-Sheet_1015.pdf
 
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Know next to nothing about steels but was wondering, does A2 stand anywhere close to INFI? I was reading about it by another knife maker and they made claims very similar to the attributes that infi is known for. A good blend of high wear resistance, good edge retention and corrosion resistance.
 
clampdaddy said:
Know next to nothing about steels but was wondering, does A2 stand anywhere close to INFI? I was reading about it by another knife maker and they made claims very similar to the attributes that infi is known for. A good blend of high wear resistance, good edge retention and corrosion resistance.
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no. According to the numbers it is not even close to 3V. However, A2 is a great steel and Busse sure made it sing.
 
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