Any knife steel with copper in it?

[jhobson]

Seems like a small amount of copper added to steel can increase corrosion resistance 5 times.
I think the copper just sits on it's own within the steel matrix, like lead, so maybe a small amount wouldn't be too detrimental to other characteristics.
Is anything actually available? O1 with .03% Cu?

[MushiSushi]

If I remember right, an analysis of japanese blade steel shows traces of copper and I believe the iron sand that they used contains a lot of copper.

but from here
http://books.google.com/books?id=LWV...gACcLdq_oAkJwM

the higher the carbon content, the more harmful is copper content and as little as 0.05% has a harmful effect on HSS Tool steel

[bigkev]

why does nobody use hss for knives............

[MushiSushi]

why does nobody use hss for knives............

They do, I know of a few people that use power hacksaw blades, reground (without getting them too hot).

[bigkev]

i tries that when i was an apprentice........to my expense....(loss of blood)
they seem a bit brittle as well...
but really held a sharp edge...

[Howard Clark]

HSS is not very impact or flex resistant. And I have never needed a "red hard" knife. Some of them do take and hold a fine edge though.

Copper does not alloy into steel. It remains as tiny discreet globules of copper, separate from the rest of the alloy, and is not really detrimental in very small amounts, but it dinna help nuthin as far as I can tell either.

What's the corrosion resistance reference, if you don't mind me asking ?

[Mike Blue]

During my readings on smelting history, it's very likely that iron was discovered as a useful material when it was used to flux copper during the melting of that metal. They are often found together in the natural state.

Some of us are guilty of making HSS knives for cutting purposes, much to the surprise of the victims of the joke...along the lines of "My knife will cut anything and yours won't. Oh, really, well my knife will cut your knife..." It goes rapidly downhill from there. I'm with Howard, it's not an all-around tool.

[jhobson]

Source was the internet
Can't find it now but I'll keep looking.

I'm sure it is too good to be true. Probably find that the effect is insignificant with steel above .5C, or doesn't protect martensite, or something.

[jhobson]

Here is one ref that talks about copper which supports some of my claim, but not the 'five times':
http://www.key-to-steel.com/Articles/Art60.htm

"0.01-0.05%, decrease the corrosion rate by a factor of two to three."

[jhobson]

Maybe we can drop a copper washer in Colin's next Wootz smelt.

[TLM]

The so called weathering steels (trade name CORTEN) contain small amounts of copper. It helps to form a fairly thick fairly stable rust layer that stops further corrosion, if that layer is removed corrosion continues. So copper is not a very good solution to achieving corrosion resistance on a knife that is continuously sharpened, besides few want their knives look rusty.

TM

[Pikebite]

.......... besides few want their knives look rusty.

Only Mojo

[Mick Maxen]

The Angel of the North is made in Corten, for its weathering properties, thats why it always looks rusty.

Mick

[Mike Blue]

The so called weathering steels (trade name CORTEN) contain small amounts of copper. It helps to form a fairly thick fairly stable rust layer that stops further corrosion, if that layer is removed corrosion continues. So copper is not a very good solution to achieving corrosion resistance on a knife that is continuously sharpened, besides few want their knives look rusty.

There is a building in Iowa called, affectionately (okay I'm being liberal with that interpretation), the Ruan Rust Tower. Outside skin is made of Corten for the very purpose stated above. Sadly, the salts used to de-ice the roads, continued the oxidation process beyond specs and the bottom twenty feet or so had to be replaced. It's not the perfect material.

[cariboo]

When they introduced a small amount of copper to the mix making train rail it revolutionalized the train industry in the States. Made them much tougher.

Small carving knives made with power hack saw blades keep an increadibly
wicked edge. I keep the length under 30 -35 mm.

Scott

Cariboo Blades Tools and Knives