What are carbides?

[Bo-dacious]

Hey guys I have some questions about carbides. What exactly are they and what do they do? I've asked about this before in a thread about something else, but I don't have a clear picture. What are the types of carbides? What do softer or harder carbides do? How are they made? What do more or less carbides do? I heard smaller carbides let the knife get sharper, but are carbides just naturally the way they are or can the Smith change them? Can someone explain carbide dispersion? And is there anything else I should know about carbides? I've found some stuff online but I feel I would get a better idea of I could ask follow-up questions. Oh yeah, and are carbides the same as microcrystals? Do all knife steels have carbides? I know it's a lot of questions but I need to learn.

Thanks guys,

Bo

 

[Wowbagger]

Hey guys I have some questions about carbides. What exactly are they and what do they do? I've asked about this before in a thread about something else, but I don't have a clear picture. What are the types of carbides? What do softer or harder carbides do? How are they made? What do more or less carbides do? I heard smaller carbides let the knife get sharper, but are carbides just naturally the way they are or can the Smith change them? Can someone explain carbide dispersion? And is there anything else I should know about carbides? I've found some stuff online but I feel I would get a better idea of I could ask follow-up questions. Oh yeah, and are carbides the same as microcrystals? Do all knife steels have carbides? I know it's a lot of questions but I need to learn.

Thanks guys,

Bo

What exactly are they

They are your friends.

what do they do

They stand at the front line of the edge and cut down what ever comes their way . . . until they get banged up or knocked down.

What are the types of carbides?

Well we'll come back to that with a link. Too many to list; it's like asking what are the types of people . . . intermingling the alloy elements produce too many variations to talk about here.

What do softer carbides do?

Allow you to sharpen your cutting tools without cussing and spending a lot of money on sharpening equipment.

What do harder carbides do?

Give you a good excuse to cuss and give you a good excuse to spend a lot of money on sharpening equipment (which many of us enjoy immensely).
Oh and they cut hard abrasive stuff . . . longer.

I heard smaller carbides let the knife get sharper,

Don't believe everything you hear . . . (unless I say it ) . . . but yes there is something to that it is subtle though. With good sharpening equipment you can get pretty basic well heat treated steel VERY SHARP. The finer grain might hold up a bit better but there are many other factors.

but are carbides just naturally the way they are or can the Smith change them?

Maybe a better way to say it is if a smith makes mistakes the carbides change in a bad way; get too large or not well anchored in the matrix. The makers of the steel have very specific steps in working the steel and if followed then things go well.

Can someone explain carbide dispersion?

Yes.

is there anything else I should know about carbides?

Not to worry about it / them at all and just buy the knife you like and if it is by one of the reputable makers you should have a good experience . . . oh and if it is predominately vanadium carbides and a lot of them (above say 4 or 5 %) plan to cuss and buy some diamond stones.

Oh yeah, and are carbides the same as microcrystals

What's a microcyrstal ?

Do all knife steels have carbides?

Yes if it is steel and an edge steel.
By definition . . . really . . . if it is "steel" then it has carbide because steel is the element IRON with the element CARBON added and that = steel.
If it has enough carbon then the steel can be heat treated and become hard enough to form at least a somewhat durable edge.

I know it's a lot of questions

. . . oh . . . no . . . pant . . . wheeze . . . don't worry about it I'll recover eventually. . . these cramps in my fingers will go away with time . . .

Thanks guys

There are "gals" here that know their stuff too
If you want to see / hear an interesting knife reviewer watch "Spydie Chick" on youtube .

 

[Wowbagger]

Here is a >>>>>link to some basic info.

 

[NJBillK]

Larrin
Do you happen to have covered this on your site?
If not, would you care to expound upon the subject?

 

[PWatkins]

They are your friends.

They stand at the front line of the edge and cut down what ever comes their way . . . until they get banged up or knocked down.

Well we'll come back to that with a link. Too many to list; it's like asking what are the types of people . . . intermingling the alloy elements produce too many variations to talk about here.

Allow you to sharpen your cutting tools without cussing and spending a lot of money on sharpening equipment.

Give you a good excuse to cuss and give you a good excuse to spend a lot of money on sharpening equipment (which many of us enjoy immensely).
Oh and they cut hard abrasive stuff . . . longer.

Don't believe everything you hear . . . (unless I say it ) . . . but yes there is something to that it is subtle though. With good sharpening equipment you can get pretty basic well heat treated steel VERY SHARP. The finer grain might hold up a bit better but there are many other factors.

Maybe a better way to say it is if a smith makes mistakes the carbides change in a bad way; get too large or not well anchored in the matrix. The makers of the steel have very specific steps in working the steel and if followed then things go well.

Yes.

Not to worry about it / them at all and just buy the knife you like and if it is by one of the reputable makers you should have a good experience . . . oh and if it is predominately vanadium carbides and a lot of them (above say 4 or 5 %) plan to cuss and buy some diamond stones.

What's a microcyrstal ?

Yes if it is steel and an edge steel.
By definition . . . really . . . if it is "steel" then it has carbide because steel is the element IRON with the element CARBON added and that = steel.
If it has enough carbon then the steel can be heat treated and become hard enough to form at least a somewhat durable edge.

. . . oh . . . no . . . pant . . . wheeze . . . don't worry about it I'll recover eventually. . . these cramps in my fingers will go away with time . . .

There are "gals" here that know their stuff too
If you want to see / hear an interesting knife reviewer watch "Spydie Chick" on youtube .

Possibly the best reply I've ever seen lol.

 

[danbot]

Hey guys I have some questions about carbides. What exactly are they and what do they do? I've asked about this before in a thread about something else, but I don't have a clear picture. What are the types of carbides? What do softer or harder carbides do? How are they made? What do more or less carbides do? I heard smaller carbides let the knife get sharper, but are carbides just naturally the way they are or can the Smith change them? Can someone explain carbide dispersion? And is there anything else I should know about carbides? I've found some stuff online but I feel I would get a better idea of I could ask follow-up questions. Oh yeah, and are carbides the same as microcrystals? Do all knife steels have carbides? I know it's a lot of questions but I need to learn.

Thanks guys,

Bo

You need to search Larrin 's threads! He's one of our metalurgist friends here. Go to knifesteelnerds I think to read up. It would take an absurd wall of text to answer all these questions here!! But please read up and tell us what you learned!

 

[Wowbagger]

But please read up and tell us what you learned!

Yes and then answer my question : Are diamonds carbides ? If so they must be the "ultimate" carbides.

 

[danbot]

Yes and then answer my question : Are diamonds carbides ? If so they must be the "ultimate" carbides.

I don't think diamonds are carbides. I could be wrong, but I think Diamonds are pure carbon. A carbide I believe contains carbon, but is not pure carbon.

 

[Lapedog]

Hey guys I have some questions about carbides. What exactly are they and what do they do? I've asked about this before in a thread about something else, but I don't have a clear picture. What are the types of carbides? What do softer or harder carbides do? How are they made? What do more or less carbides do? I heard smaller carbides let the knife get sharper, but are carbides just naturally the way they are or can the Smith change them? Can someone explain carbide dispersion? And is there anything else I should know about carbides? I've found some stuff online but I feel I would get a better idea of I could ask follow-up questions. Oh yeah, and are carbides the same as microcrystals? Do all knife steels have carbides? I know it's a lot of questions but I need to learn.

Thanks guys,

Bo

When they make steel it is mostly iron. The other element added to iron to make it steel is carbon. Most steels don’t have just carbon and iron they have other elements added in. Some of these elements can combine with some of that carbon to form carbides.

The other elements commonly mixed into steel that form carbides are chromium, (some chromium will become chromium carbide some will not, that which does not will contribute to making the steel more rust resistant) molybdenum, tungsten, vanadium, and niobium. (Niobium and vanadium that do not combine to form carbides can help refine the steel’s grain structure abd make the bonds between the steel grains stronger)

Chromium carbides tend to be the biggest and vanadium and niobium tend to be the smallest and hardest. Either way they are all microscopic. Imagine that steel is like a block of cement and the carbides are hard stones mixed into the cement, like concrete. Carbides are harder than the surrounding steel itself.

Now imagine the edge of the knife is like a hill top that gets worn away as it is used. The carbides are like boulders sittinf at the top of that hill. As the hill is worn away those boulders are exposed and eventually fall out. But while they are sticking out of the top of the hill they act as hard points sort of like mini saw teeth that help the cut.

Here is a microscopic picture of steel surface, in this case D2 steel. The white parts are carbides the surrounding grey is the actual steel itself.

 

[Alberta Ed]

Lots of elements form carbides: vanadium, niobium, chromium, for instance. Think of them as the gravel in cement (steel). Check out Spyderco's catalogue; there is an excellent section on various elements in steel and how they work.

 

[danbot]

When they make steel it is mostly iron. The other element added to iron to make it steel is carbon. Most steels don’t have just carbon and iron they have other elements added in. Some of these elements can combine with some of that carbon to form carbides.

The other elements commonly mixed into steel that form carbides are chromium, (some chromium will become chromium carbide some will not, that which does not will contribute to making the steel more rust resistant) molybdenum, tungsten, vanadium, and niobium. (Niobium and vanadium that do not combine to form carbides can help refine the steel’s grain structure abd make the bonds between the steel grains stronger)

Chromium carbides tend to be the biggest and vanadium and niobium tend to be the smallest and hardest. Either way they are all microscopic. Imagine that steel is like a block of cement and the carbides are hard stones mixed into the cement, like concrete. Carbides are harder than the surrounding steel itself.

Now imagine the edge of the knife is like a hill top that gets worn away as it is used. The carbides are like boulders sittinf at the top of that hill. As the hill is worn away those boulders are exposed and eventually fall out. But while they are sticking out of the top of the hill they act as hard points sort of like mini saw teeth that help the cut.

Here is a microscopic picture of steel surface, in this case D2 steel. The white parts are carbides the surrounding grey is the actual steel itself.

NVM

 

[knarfeng]

When there is less than 0.77% by weight carbon in a steel alloy, the carbon atoms stay inside the matrix of Iron atoms (making the iron "steel"). When there is more than 0.77% carbon, it is not possible for all the carbon atoms to fit inside the matrix. The
"free" carbon can then react with other elements, which it proceeds to do. If nothing else, it will react with some of the iron, forming cementite.

The compounds formed by the reactions with the "free carbon" are ceramic particles and are significantly harder than the parent steel. Steels that contain carbides can be thought of as similar to concrete. The steel is the cement and the carbides are the aggregate. The carbides add wear resistance to the steel because they are harder than the steel matrix.

 

[The Mastiff]

Here is some basic information including the hardness of the different carbides : http://www.crucibleservice.com/eselector/general/generalpart1.html

 

[halden.doerge]

They are your friends.

They stand at the front line of the edge and cut down what ever comes their way . . . until they get banged up or knocked down.

Well we'll come back to that with a link. Too many to list; it's like asking what are the types of people . . . intermingling the alloy elements produce too many variations to talk about here.

Allow you to sharpen your cutting tools without cussing and spending a lot of money on sharpening equipment.

Give you a good excuse to cuss and give you a good excuse to spend a lot of money on sharpening equipment (which many of us enjoy immensely).
Oh and they cut hard abrasive stuff . . . longer.

Don't believe everything you hear . . . (unless I say it ) . . . but yes there is something to that it is subtle though. With good sharpening equipment you can get pretty basic well heat treated steel VERY SHARP. The finer grain might hold up a bit better but there are many other factors.

Maybe a better way to say it is if a smith makes mistakes the carbides change in a bad way; get too large or not well anchored in the matrix. The makers of the steel have very specific steps in working the steel and if followed then things go well.

Yes.

Not to worry about it / them at all and just buy the knife you like and if it is by one of the reputable makers you should have a good experience . . . oh and if it is predominately vanadium carbides and a lot of them (above say 4 or 5 %) plan to cuss and buy some diamond stones.

What's a microcyrstal ?

Yes if it is steel and an edge steel.
By definition . . . really . . . if it is "steel" then it has carbide because steel is the element IRON with the element CARBON added and that = steel.
If it has enough carbon then the steel can be heat treated and become hard enough to form at least a somewhat durable edge.

. . . oh . . . no . . . pant . . . wheeze . . . don't worry about it I'll recover eventually. . . these cramps in my fingers will go away with time . . .

There are "gals" here that know their stuff too
If you want to see / hear an interesting knife reviewer watch "Spydie Chick" on youtube .

My man.

 

[Mo2]

Good site here too http://zknives.com/knives/steels/index.shtml

And here


http://knifesteelnerds.com

 

[miso2]

I also like Jay Fisher's web site.

 

[Larrin]

Carbides are particles formed between carbon and other elements such as iron, chromium, and vanadium. They increase wear resistance due to their high hardness but also reduce toughness. They are generally not the limiting factor for sharpness. Their size and distribution can be affected somewhat by the knifemaker but composition of the steel and production process by the steel company are much more significant. Essentially all knife steels have carbides though not all have the larger carbides that contribute to wear resistance. Virtually all of my articles reference carbides in some way. Maybe start with this one: http://knifesteelnerds.com/2018/03/16/micrographs-of-niolox-cpm-154-and-aeb-l/

 

[Bo-dacious]

Wow bagger: that's good information thank you very much. The reason I'm asking is because I want to open a knife sharpening business eventually. I was reading about carbides and someone called them microcrystals.

Danbot: I'm very busy these days, but I will try to post what I have learned to here when I get around to it!(my first priority is learning this stuff. I don't mean you guys are less important lol I just have to manage my time)
.
Lap: thank you, very good visuals and imagery, that helped a lot. I always thought carbides were round.

Knarfeng: great information, thank you!

Thank you to everyone who helped out, this is really aiding my learning.

It's gonna take a while to read all those articles as I have many others I'm reading at this point in time, but I will get around to them eventually.

Bo

 

[marcinek]

Larrin and knarfeng , you guys are the heavy hitters (no offense to everyone else, no doubt you all will agree)...so I have a carbide question for you two that I have had for years.

Can they be "aligned" in steel? If they can, can they aligned by stropping?

 

[Lapedog]

Larrin and knarfeng , you guys are the heavy hitters (no offense to everyone else, no doubt you all will agree)...so I have a carbide question for you two that I have had for years.

Can they be "aligned" in steel? If they can, can they aligned by stropping?

Not answering your point exactly but I do know that the carbides often form in rows called carbide banding when it is forged or rolled. Just thought it was interesting.

I think when they anneal the knife during heat treat it helps break up these bands.