Differences In Steels

[Jammer Six]

So if I understand this correctly, the differences in steels can be measured and recorded, because the different ingredients are known and the process for creating a given steel is known.

However, that can't be said about Damascus steels, because there is no uniformity between the processes used to create it. Therefore, every batch of Damascus steel is literally a one-off.

Have I got that right?

 

[Fanglekai]

No. Most alloys allow a small variance in the mass fractions of some of the elements. Each batch of raw steel may vary in its composition. On top of that, heat treatment performed exactly the same doesn't always yield the same results, which is why testing needs to be done to determine if the microstructure of the steel is what it should be. Rockwell and other hardness testing methods and standards exist in engineering to check if a heat treatment is near what it should be. Further analysis of the microstructure is necessary in some cases. Just because a knife blade says S35VN, for example, doesn't mean it's identical to other blades with the same alloy.

Damascus is pattern welded steel typically done in small batches with known alloys. The heat treatments are known. The steel can be tested. There is more variance between batches due to the process of pattern welding two alloys. However, a skilled and knowledgeable person can provide a consistent product.

Being a "one off" doesn't mean anything. Everything that isn't a pure crystalline substance designed to be uniform is going to have differences at the atomic level.

 

[Jammer Six]

I see.

So are there standards of Damascus steel that are written with the various combinations of ingredients?

 

[Phixt]

To the same degree, all steel types like 3v...nvm...

Just because a knife blade says S35VN, for example, doesn't mean it's identical to other blades with the same alloy.

I like when someone who knows way more than me says exactly what I'm thinking. Hair more vanadium, hair less, different alloy, plus everything else Fanglekai said.

 

[madcap_magician]

I see.

So are there standards of Damascus steel that are written with the various combinations of ingredients?

There are and there aren't. If you get Damascus from any of the established manufacturers, including (but not limited to) Chad Nichols, Brad Vice, Damasteel, etc., the component steels will be known and published, and the manufacturing methods will be consistent and yield consistent results. Homebrew maker materials, quality, and consistency will vary widely from melted pot metal to extremely high end.

 

[Jammer Six]

We have different ideas of what a standard is.

My idea is a written standard that generates the same result no matter who makes it. If a known maker meets the standard, he meets the standard. If a guy in his backyard meets the standard, he meets the standard.

If the component steels are known, and the attributes are published, that's well and good, but the combination of those steels can change that, can't it?

So if a known maker publishes his list of ingredients, doesn't combining those ingredients change those attributes?

Or did you mean to say that various known maker publish the results on their combinations, and then meet those specifcations each time they make that Damascus steel?

I can see how that would be easier, for instance, in the case of Damasteel, which is, as I understand it, a powdered product. The powder is the same each time, and the company has the wherewithal to make the process the same each time.

How does a guy swinging a hammer generate consistent results?

What are the tests that reveal those results? (Use small words, I'm an expert at wood, not metal.)

 

[Aquaholicc]

No. Most alloys allow a small variance in the mass fractions of some of the elements. Each batch of raw steel may vary in its composition. On top of that, heat treatment performed exactly the same doesn't always yield the same results, which is why testing needs to be done to determine if the microstructure of the steel is what it should be. Rockwell and other hardness testing methods and standards exist in engineering to check if a heat treatment is near what it should be. Further analysis of the microstructure is necessary in some cases. Just because a knife blade says S35VN, for example, doesn't mean it's identical to other blades with the same alloy.

Damascus is pattern welded steel typically done in small batches with known alloys. The heat treatments are known. The steel can be tested. There is more variance between batches due to the process of pattern welding two alloys. However, a skilled and knowledgeable person can provide a consistent product.

Being a "one off" doesn't mean anything. Everything that isn't a pure crystalline substance designed to be uniform is going to have differences at the atomic level.

So from the information you've given me , I can safely say that 1 batch of M390 Bohler steel could be drastically different than say if Crucible tried to manufacture M390?..
You would think they have the alloys down to a science in 2017 and anyone should be able to create a consistent product with today's technology? I understand their will be hiccups in how homogenous 1 batch might be over another but naturally the manufacture would just call it a loss and throw it out?
If we know the chemistry of an alloy I don't see why their should be so many .."variables" when producing such a product?

Also..would you go as far as to say the Rockwell of certain steels are tested per the manufacturers? Example say Crucible thinks s30v just shines like a diamond at let's say 53RC. But Bohler laughs at their face because they have the resources and facts that prove s30v is way too brittle at 53 so they make theirs at 51?
(I know nothing about the "logistics" of Rockwell i.e if they are their own entity or rather just a standardized sub set of numbers and stats? I just haven't given that much research time to this side of knives sadly)

 

[Danke42]

There's no standards.

Knife makers are like chefs making a pizza; it's an art. Some use one cheese and others use three. The next one won't use olives but will use anchovies.

You want the same meal anywhere in the world you go to McDonald's and have a cheeseburger. It's the same and uninspiring.

You want art you find a local chef and see what they can do. Same goes for a Damascus blade. It's art; it's not an excel chart.

 

[Jammer Six]

There's no standards.

Knife makers are like chefs making a pizza; it's an art. Some use one cheese and others use three. The next one won't use olives but will use anchovies.

You want the same meal anywhere in the world you go to McDonald's and have a cheeseburger. It's the same and uninspiring.

You want art you find a local chef and see what they can do. Same goes for a Damascus blade. It's art; it's not an excel chart.

That's pretty much what I said in my first post, and the way I thought it was. I thought I'd ask, though, it case there was an excel chart I wasn't aware of.

 

[Aquaholicc]

There's no standards.

Knife makers are like chefs making a pizza; it's an art. Some use one cheese and others use three. The next one won't use olives but will use anchovies.

You want the same meal anywhere in the world you go to McDonald's and have a cheeseburger. It's the same and uninspiring.

You want art you find a local chef and see what they can do. Same goes for a Damascus blade. It's art; it's not an excel chart.

You can't sit there and tell me their are NO standards lol. If you look at what makes s30v and s35VN different (that 4% Niobium goes along way in Edge retention), then you must realize that things are added/changed not just for fun/art?

This is where we will highly disagree and there is absolutely nothing wrong with it besides the point that I take information and process it differently than you. You see steels as just something a manufacturer puts in a melting pot and hopes for the best? I see it has chemistry/data/engineering/math..all these things come together to make one steel play out differently than another.

But hey I'm just a man of statistics and facts.

 

[Fanglekai]

So from the information you've given me , I can safely say that 1 batch of M390 Bohler steel could be drastically different than say if Crucible tried to manufacture M390?..
You would think they have the alloys down to a science in 2017 and anyone should be able to create a consistent product with today's technology? I understand their will be hiccups in how homogenous 1 batch might be over another but naturally the manufacture would just call it a loss and throw it out?
If we know the chemistry of an alloy I don't see why their should be so many .."variables" when producing such a product?

Also..would you go as far as to say the Rockwell of certain steels are tested per the manufacturers? Example say Crucible thinks s30v just shines like a diamond at let's say 53RC. But Bohler laughs at their face because they have the resources and facts that prove s30v is way too brittle at 53 so they make theirs at 51?
(I know nothing about the "logistics" of Rockwell i.e if they are their own entity or rather just a standardized sub set of numbers and stats? I just haven't given that much research time to this side of knives sadly)

Let me give an example so it's more clear. Here's a picture of the composition of D2:

from: http://www.azom.com/article.aspx?ArticleID=6214

There is a range of acceptable fractions for each element. This is common with many steels. It means that not all D2 has the same elemental composition. Then with heat treatment there are even more differences. Starting out with a different composition is going to yield different steel from batch to batch. Are the differences noticeable? That's a separate issue.

I'm not saying that Crucible would make M390 differently from Bohler. I'm saying batch to batch for every steel regardless of who makes it there are going to be differences at the atomic or molecular level. If Bohler makes M390 in a batch of let's say 1000 lbs, is that batch going to have exactly 19.00000 lbs of carbon? (1.9% carbon) What if it has 18.99999 lbs of carbon? Is that close enough or does it have to be exactly 19.00000 lbs of carbon? Where is the line drawn for what is called M390? That's where specifications and tolerances come into play.

And that's precisely the point. There will always be differences. I'm not suggesting those differences are going to amount to anything that anyone would be able to reliably tell apart. The point is that there are specifications and if something is "good enough" for a given application then that's what happens.

Going from raw steel to a finished product like a blade requires shaping the blade. Grinding at high temperatures will affect the steel. Heat treatment adds additional changes. What if the blade is heat treated with 1 degree of difference from another blade? What about 0.5 degrees of difference? What changes does that cause? Are they noticeable?

There are numerous variables and without going to extreme lengths to control everything it's impossible to achieve the exact same results every time. What we get is something that's virtually identical or nearly impossible to tell the difference. However, looking at the microstructure of any non-homogeneous material, it's evident that piece 1 of steel A is not identical at a molecular or atomic level to piece 2 of steel A. Like I mentioned before, the only substances that will be identical are pure crystalline ones, most likely created in a lab.

So, my long-winded point is that Damascus is not the only steel that is going to vary from batch to batch. Every non-homogeneous material is going to vary. The question is really this: "By how much must it vary for someone to notice a difference?" In the case of Damascus, it depends on the materials and methods just like any other steel. I hope this clarifies my previous comments.

 

[Jammer Six]

I hope this clarifies my previous comments.

It does.

It sounds to me like there is no standard for Damascus steel, but that it doesn't really differ from other steels that way. All steels are different depending on their specific path; good enough, however, is the supreme standard.

 

[jdm61]

Properly made damascus is the sum of its component steels. Using say Aldo 1084 with around .87 C and 15N20 with .75 And 2.00 nickel, even counting for some carbon loss, you have the potential to end up with what is essentially 1080 with .8 percent nickel if you use the 60/40 dark/silver steel mix. What that means in simple terms is that you have a 1080 that is tougher.

 

[knarfeng]

Not a good idea to use powder metallurgy steels as a comparing point for standardization of alloys. The processing involved in producing powder metallurgy alloys is proprietary to each company, so they are each somewhat different. Even if two companies made alloys with exactly the same composition, there would still be variation between them.

Stick to melt alloys and you are closer to having a standard. But even melt alloys can have differences in processing. And as has been pointed out, the compositions have ranges, not exact percentages.

 

[Fanglekai]

It does.

It sounds to me like there is no standard for Damascus steel, but that it doesn't really differ from other steels that way. All steels are different depending on their specific path; good enough, however, is the supreme standard.

Almost but not quite. "Damascus" isn't one material. You can't go on azom or matweb and find just one "formula" for Damascus, because there are many ways to make pattern welded steel. There are numerous possible material combinations. A steel is called D2 if the elemental composition of the alloy matches the specification. Some specific alloys have names. Some have a specific elemental composition with given tolerances. If I make an alloy similar to the alloy we call D2, but I change the % carbon to where it falls outside the specification, then that alloy cannot be called D2. The only alloys that can be called D2 are those that match the specification for D2. So, even though I can call piece 1 D2, I can also call piece 2 D2 as long as both pieces have elemental composition that matches the specification. They are not exactly the same, but because the specification allows a range, both pieces can be called D2. Are there differences that matter for a given application? That would have to be tested. As long as an alloy matches the composition of a specification then it is whatever that alloy is named. So you could make 1000 batches of D2 steel and they're all a bit different but they're all D2 if they match the spec.

Like madcap_magician said, if you get "Damascus" from a particular maker, that maker is probably going to have their own formula. Each maker presumably will have their own standards as to what their Damascus is. Maybe they get a batch and it has too little carbon in their 1080 (or whatever material). If they care about doing things properly they'll send the batch back to the foundry if it's outside of spec. Just like D2, a steel like 1080 allows a range.

There isn't a universal formula for Damascus, so it's basically whatever the maker comes up with and any variances are going to be from how closely the maker keeps to a specific elemental composition from batch to batch. A maker could use a specific formulation just like D2 or M390 for their Damascus. In that regard it would be the same as any other alloy. It all depends on what the maker does.

"Good enough" is determined by the application. The blades of a turbine require very close tolerances. A pocket knife really doesn't need that. In the end these are just blades to cut stuff in typically mundane situations. Check out the Victorinox factory tour video. There's a scene where a worker checks the elemental composition of a batch of steel to see if it's within spec. If it is within spec, they use it. If it's not for whatever reason, they don't use it.

 

[Fanglekai]

Not a good idea to use powder metallurgy steels as a comparing point for standardization of alloys. The processing involved in producing powder metallurgy alloys is proprietary to each company, so they are each somewhat different. Even if two companies made alloys with exactly the same composition, there would still be variation between them.

Stick to melt alloys and you are closer to having a standard. But even melt alloys can have differences in processing. And as has been pointed out, the compositions have ranges, not exact percentages.

Also this! Just because the composition of an alloy is published doesn't mean that two companies will make it the same way. This is where intellectual property comes into play and where the specification for what constitutes steel A may not be public knowledge. A random company can't just go and make Coca Cola or The Colonel's secret recipe for chicken at KFC. If they don't own the rights, they can't claim to make M390 or whatever the alloy is.

This is the Victorinox tour video. The part I was referencing starts around 6 mins:

 

[Danke42]

You can't sit there and tell me their are NO standards lol. If you look at what makes s30v and s35VN different (that 4% Niobium goes along way in Edge retention), then you must realize that things are added/changed not just for fun/art?

This is where we will highly disagree and there is absolutely nothing wrong with it besides the point that I take information and process it differently than you. You see steels as just something a manufacturer puts in a melting pot and hopes for the best? I see it has chemistry/data/engineering/math..all these things come together to make one steel play out differently than another.

But hey I'm just a man of statistics and facts.

Damascus is a pattern, not an element or even a recognized or agreed upon alloy.

 

[Jammer Six]

Then how can it be claimed that Damascus from more than one maker can be "consistent", if there are jillions of recipes for Damascus, and each maker makes it differently?

If you get Damascus from any of the established manufacturers, including (but not limited to) Chad Nichols, Brad Vice, Damasteel, etc., the component steels will be known and published, and the manufacturing methods will be consistent and yield consistent results.

 

[DeadboxHero]

Then how can it be claimed that Damascus from more than one maker can be "consistent", if there are jillions of recipes for Damascus, and each maker makes it differently?

Modern Damascus is a process not an alloy.