Damascus steel

[BK911]

Accidentally. Haha!!




[Limg]http://forums.pelicanparts.com/uploads26/10000048761776553346.jpg[/img]

[pwd72s]

Interesting

[Bill Douglas]

I think it's the same as the Chinese samurai sword. As it's forged it's folded and folded and folded... And each fold puts carbon into the steel.

[Bob Kontak]

Originally Posted by Bill Douglas

I think it's the same as the Chinese samurai sword. As it's forged it's folded and folded and folded... And each fold puts carbon into the steel.

That's what I have taken away from youtube university.

I'm not sure how carbon is created. I wouldn't think it gets hot/active enough to change atomic structures but I have not researched.

[Chocaholic]

Some hi quality Damascus steel is still available today. This is one of my favorite pocket knives from Japan:

[zakthor]

It sure would be fun to know what the original damascus blacksmiths ‘knew.’ They had a model for metal and it let them make amazing blades. So many things had to be done just right.

I think modern science knows everything about their metallurgy and weve figured out their process but we also look at the problem entirely different from them. I dont think they even knew what tungsten and vanadium were.

To me a damascus blade means more than just folded metal that makes a pattern. Ive heard the pattern comes from holding the steel at exactly the right tempersture for a long time and the metal migrates to form the layers. The dark metal is hard and brittle crystal austentite and the other stuff is softer.

Those old blades are like the antikythera mechanism of metallurgy - it kinda sort of indicates these old timers knew more than we suspected, certainly they made due with less theory.

[john70t]

I've read a little bit about Japanese Katana. 1,000 fold techniques. Quenching and adding carbon throughout the process. Not necessarily unique to them. Most mass-produced swords were probably not. What is amazing is the utilization of limited iron availability to work with back then.

Each advanced sword maker took a lifetime of secret knowledge to the grave...

One thing that stood out is the design of softer steel in the center, surrounded by the leading edge blade layer of hardened steel, which tends to be brittle.

The 'softer' inside center absorbs and spreads impact forces, while the 'harder' layer retains it's edge and rust resistance.

[zakthor]

Originally Posted by john70t

I've read a little bit about Japanese Katana. 1,000 fold techniques. Quenching and adding carbon throughout the process. Not necessarily unique to them. Most mass-produced swords were probably not. What is amazing is the utilization of limited iron availability to work with back then.

Each advanced sword maker took a lifetime of secret knowledge to the grave...

One thing that stood out is the design of softer steel in the center, surrounded by the leading edge blade layer of hardened steel, which tends to be brittle.

The 'softer' inside center absorbs and spreads impact forces, while the 'harder' layer retains it's edge and rust resistance.

https://en.wikipedia.org/wiki/Wootz_steel

[kach22i]

Originally Posted by zakthor

https://en.wikipedia.org/wiki/Wootz_steel

From the link:

In Sri Lanka, this early steel-making method employed a unique wind furnace, driven by the monsoon winds.

Interesting.

[flatbutt]

Originally Posted by Bob Kontak

That's what I have taken away from youtube university.

I'm not sure how carbon is created. I wouldn't think it gets hot/active enough to change atomic structures but I have not researched.

I think the carbon comes from the wood fire. Maybe

[unclebilly]

To answer a couple questions…

Carbon is not formed. It gets driven into the steel either from the coals in the hearth or from a yellow carburizing flame. The folding and hammer welding does create layers of high carbon and low carbon steel and if heat treated correctly, you can get a tough yet sharp blade that can hold an edge.

I doubt that these blades had great corrosion resistance. Nickel or chromium would be needed to get there.

Also one more misconception, hard steel does not have good corrosion resistance. It is the opposite, this is why knife materials like 22cv are unique. They give good corrosion resistance and hold an edge.

[Bob Kontak]

[QUOTE=unclebilly;12637465]To answer a couple questions…

Carbon is not formed. It gets driven into the steel /QUOTE]

Cool. Thanks guys.

[KFC911]

How do Shun knives stack up to old techniques ... I ventured down that rabbit hole recently ... they are almost too pretty to use ... and I am not a chef either

Because of you guys ... this DIY site has cost me bigly ...

Just because ...

[GH85Carrera]

There was an interesting series called Forged in fire for several years on History channel. I don't know if they are still in production.

Anyway, they had a challenge thing were different blacksmiths competed on identical forges and equipment in the same room. They regularly made Damascus steel. Usually they layered different types of steel, and folded it many times. There are many types of Damascus steel, and they used many varieties of steel.

It was an interesting thing to watch the competitors make some interesting blades from daggers to swords and axes and blades I had never heard of. The testing often had the testers cut pig carcass in half.

It is not just folding steel that makes Damascus steel, it requires different types of steel layered and forged together. They made some very pretty blades. I had no idea that the USA had so many different people forging items by hand in the modern times. Some as just a hobby, and some as full time profession.

[masraum]

This is a pretty cool video by Veritasium on the Samurai sword thing (Japanese, not Chinese for Bill D). They usually do a pretty good job of getting the technical details worked into their videos in a way that most folks will understand. I haven't watched this in many months. I don't remember how deep they went into the technical aspects.



I think that most damascus makers these days are focused on the appearance of the steel more than the particular qualities of the steel (durable, sharp/edge retaining, flexible/not brittle), but I'm sure there are some.

Ancients, of course, didn't know that they were creating carbon nanotubes. They just figured out the right recipe and over many, many years figured out tweaks to the recipe to make their steel better and better.

[john70t]

Caveman method still works today (missing the post-processing forging part):

https://thekidshouldseethis.com/post/primitive-technology-crafts-an-iron-knife-made-from-bacteria

“The ore was a species of bacteria that lives by oxidizing iron dissolved in ground water. It appears as an orange/yellow cloudy precipitate in creeks and ponds. It’s a very common natural occurrence and can be found on all continents. I collected the diluted ore and poured it into a large, porous ceramic pot I made. The water leaked out, leaving behind the concentrated iron bacteria “mud” like substance. I dried it out until it resembled rusty earth. It took a month to collect the ore for one 2 hour smelt, from a stretch of creek about 20 meters long.”

[Bill Douglas]

At high school we had a full on engineering class. We had lathes that had been used for making heavy artillery guns in WW2, new lathes, milling machines, welding equipment and a forge.

Teacher had us heating bright mild steel in the forge, hammering it out on anvils and then dipping it into a container of carbon. This was case hardening schoolboy style. Just like the Chinese (must be bad AI - my apologies Japan ) did with their sammy swords but folded it lots of times.

The carbon was some product specifically for the steel type.

[unclebilly]

The caveman video has me wondering if Damascus steel wasn’t a product of need… casting was pretty rough. Take that blade and heat it up orange and hot work it some to get a better shape or finish… the next thing is to fold it onto itself…

[HobieMarty]

Yeah but can they cut through an aluminum can and then still slice a tomato???

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[WolfeMacleod]

Originally Posted by zakthor

It sure would be fun to know what the original damascus blacksmiths ‘knew.’ They had a model for metal and it let them make amazing blades. So many things had to be done just right.

I think modern science knows everything about their metallurgy and weve figured out their process but we also look at the problem entirely different from them. I dont think they even knew what tungsten and vanadium were.

To me a damascus blade means more than just folded metal that makes a pattern. Ive heard the pattern comes from holding the steel at exactly the right tempersture for a long time and the metal migrates to form the layers. The dark metal is hard and brittle crystal austentite and the other stuff is softer.

Those old blades are like the antikythera mechanism of metallurgy - it kinda sort of indicates these old timers knew more than we suspected, certainly they made due with less theory.

It was made of a cricible steel called Wootz.

I spent about 13 years making "modern" Damascus as a knife and swordsmith. Modern Damascus is pasically pattern welded steel.

And most of what you see today is cheap laser-etched, made to look like Damascus.