Carbon Steel / Stainless Steel Damascus

the4th

the4th

Joined
Mar 20, 1999
Messages
1,163
I seem to recall reading on the forums recently that Carbon steel and Stainless steel shouldn't be used together in a laminate (San Mai) construction due to the accelerated corrosion that would occur between the metals. (Something to that effect anyway.) However, I just received the new A.G. Russel catalog and they are selling a "Damascus" knife that is stainless and carbon steels mixed. Any input on the projected life expectancy of a mix like this. It's a handsome knife, not fantastic, but dressy. Sells for $99.00
 
Here is the rundown and pic of the knife.
<img src=http://www.agrussell.com/agrussell/a340-da.jpg>
Damascus steel comes in many patterns and several types. One of the types that really attracted me when I was young was the steel and nickel-iron (meteorite) random pattern used in the Malay Archipelago for the kris of the Malay pirates. Today we can use a high nickel content steel to get the same effect without having to search for fallen stars. What you have is stainless steel stripes throughout the basic material of non-stainless high carbon steel. Since the blade is etched with acid to make the pattern stand out you need only a very minimum of effort to maintain the blade and to keep it from rusting. I suggest you use a drop of "Rustfree" when putting the knife away after use.

What you see here is a handsome 3 3/4" closed locking folder with a 3" general purpose blade of a very good looking damascus, nickel silver bolsters and handles of Chinese quince, a very highly figured wood from mainland China. This knife is made exclusively for us in Seki City, Japan.

 
Well I think that this is a good looking knife, and if I was in the market, I would but it. It seems to me as long you keep oil or some kind of protectant on it, rust would not be much of a problem. I have made 440C knives that have rusted. So I am of the opinion that is a good idea to keep some kind of protectant on most any blade. I don't guess I have been much help here, but if you want the knife, buy it. I wood.
Chris, Top of Texas Knives
www.toptexknives.com

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Hey Chris,
I'm not really in the market either, just curious if this was a manufacturing faux pas by some beginning knife maker or if the issue of Stainless/Carbon Damascus is really a "non-issue."

Thanks!
 
You know that is a hard one. To me I guess it would not make that much difference. I don't know how much is fact or how much is opinion. Sorry, I'm not much help with this one.
Chris, Top of Texas Knives
www.toptexknives.com

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When two different metals are in contact in an electrolytic solution such as salt water you have an electric battery; current flows and the "less noble" metal is corroded. The phenomenon is very familiar to marine architects. It only happens in an electolytic solution, though. If the knife has no coating of oil on it and it's really soaked in perspiration it could happen. The possibility is pretty remote. Think of all those steel knives with brass bolsters and guards you have. Just use reasonable care to keep it oiled like any non-stainless knife.

That blade is beautiful. Don't let fears of corrosion keep you from buying it -- just don't get so fearless you never oil it.

-Cougar Allen :{)
 
I think that I am going to have to bounce this question off of my Chemestry teacher Dad to see if it true. I am curious about the mechanics of this type of corrosion. I know that there are serious corrosion problems when Aluminum and iron are in contact, and that a method of keeping the iron from giving up its electrons is necessary to minimize corrosion. I know that boats use zinc to keep corrosion minimized. I do not know whether or not that this type of reaction can occur between two ferrous based materials.....I wonder what that knife would look like with all of the carbon steel eaten away....

YeK
 
The idea of using sacrificial zinc is because that's a "less noble" metal than just about anything (let's not get into what "less noble" means ...) it's the zinc that gets corroded and not the steel. It's customary to screw one or more lumps of zinc to a steel boat and replace them from time to time. It's been tried on cars -- a lump of zinc only protects the steel near it, but if you scatter a few around the underside of your car.... Galvanizing -- zinc plating -- works the same way; even if the coating is worn through in spots it still protects the steel. Another way is to apply a small voltage to make sure the current flows in the direction you want it to -- they protect oil pipelines that way, preserving hundreds of miles of pipeline with just a few cents a month worth of electricity.

I don't know if electrolysis can occur between two steels. I'm inclined to doubt there would be much effect unless they're very different alloys like stainless and carbon steel.

-Cougar Allen :{)
 
The "replacement reaction" is true. (I *ALMOST* majored in Chemistry!
smile.gif
)

That reaction is the reason that aluminum wiring was discontinued a number of years back for use in mobile homes. It seems the aluminum in the wire and the standard copper terminals it was being hooked up too would corrode and cause a large gap. Large gap + large amounts of electricity = spark. Spark + surrounding combustible materials = fire.

I was just wondering HOW MUCH reaction could occur and how quickly. I unfortunately never studied mettalurgy so I thought I'd ask. I guess if the metals were closer together in content (like 5160 and ATS34) they might slow the reaction more than say an 01 and 420 mix might.
 
Gentlemen; first off, what you see depicted above is NOT Damascus, although it is often referred to by that term. What that knife is made of is pattern welded steel. Rods of differing carbon content are heated while in a bundle, and then welded together by pounding with a hammer. The twisting of the rods produces a pleasant pattern.

Actually, the patterns seen today are primitive compared to the shotgun bbls. produced by pattern welding in the mid to late 1800's. Even after the introduction of the stronger fluid steel bbls., pattern welded 'Damascus' bbls. continued to command a premium price.

'Damascus' steel today has only one purpose: decoration. There was a day (starting about AD 800, ending around 1700 or so) when Damascus, or 'Wootz' steel offered advantages to knife and sword blades. Japanese blades, Nihonto, are made from Wootz steel. The layers are parallel to the surface, along the length of the blade. Contrast this with present day pattern welded steel, where the blade is fashioned by cutting across the cross sections of the welded, twisted rods.

I am unaware of any galvanic activity ever reported in Damascus or pattern welded steel. One consideration has been raised concerning the migration of carbon from the high carbon steel layers to the low carbon steel layers. This seems more to be fantasy than fact. Nohonto exist from before AD800, but one Nihonto, 'The Little Crow,' which dates from about 800, still clearly shows lamination marks, which argues against carbon migration to any significant degree.

Damascus, or pattern welded steel; I love it. For decoration and extremely light use only. Frankly, to use one of these knives for general use is a lot like letting your 4 yo son use your Ti golf clubs for knocking rocks around the yard.

Hope this helps. Walt
 
The carbon migration occurs while the metal is hot during forging. There's been some discussion on the net about exactly how long it takes (perhaps a minute or two of forging hot metal before carbon content is uniform throughout, or maybe a little longer than that) and whether it would be possible to work very quickly and hammer-weld a couple of pieces together and heat-treat asap and still have any difference in carbon content.... The carbon content is uniform throughout by the time a pattern-welded blade is finished. The two steels still look different when etched, but the difference in appearance does not reflect any difference in carbon content in the finished blade.

Carbon migration does not occur in cold steel, or if it does it's extremely slow (there is argument about whether carbon can migrate in cold steel on a time scale of centuries).

IIRC there's more info at swordforum.com and maybe at netsword.com

In practical terms, this means if you choose a low-carbon steel and a high-carbon steel you must calculate the proportions and carbon content of the two steels so the average of the two (minus carbon burned out in forging and heat-treating) will give you the carbon content you want in the finished blade. Watch out or you'll end up with mild steel like the Windlass blades.

-Cougar Allen :{)
 
I work in the pressure vessel industry.Carbon and stainless are welded together using various procedures, there is no reaction between the two metals. The difference in the two metals is a higher chrome content in the stainless. Chrome is what makes stainless, stainless. Hope this helps. Why do some of you always end a reply with a saying? Never pet your dog when it's on fire!
 
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