fulcrum
Member
In commerically produced steel there is no amount of unintentional metal added to the mix. There are extremely small variances allowed in trace elements, which are permitted only in extremely small amounts. Steel batches are regulated quite closely, and you can rest assured that millions of tons of steel are identical in composition. If there were an impurity, or excess of any one element in the process it would likely become apparent long before anything useful was made out of the steel. Even the smallest alloy additions greatly affect the properties of steel, which shows up during forming of components like razor blades.
It is true that some metal foundaries use different melt practices, and there are some steels that contain copper. But if copper is in the steel you can bet its intentional, and serves a very specific purpose. When copper is added it is most often used to improve hardenability in complex alloy steels (for specific applications, which require high cost alloys).
Regular utility razor blades are very often made of plain carbon steel, which contain a maximum 0.6 weight percent copper.
A point of note is that when copper is in metallic form it is resistant to corrosion in seawater. Copper-nickel alloys are used exclusively for marine piping systems on navy ships.
The copper that is so damaging to saltwater tanks exists in the form of the cuprous ion. Not metallic copper. I'm not suggesting that you plumb your tank with copper. That would be dumb. But the amount of metallic copper that potentially exists in a chip of a razor blade is quite miniscule. Even then the metallic copper would have to be dissociated into cupprous ions. This is not likely at all.
There is no doubt common razor blades will rust. Rust is simply a sign that the metallic atoms present have oxidized to form a more stable compound. (they dont dissolve to any noticeable extent) Again, once a thick layer of oxide forms on the surface it will likely passivate the steel and prevent further oxidation. Corrosion slows down exponentially with the increasing thickness of the oxide layer, assuming the rust is not scraped off, exposing fresh new surface.
If it were me, I would get the thing out of my tank too, just because it doesn't belong there. But metallurgy is not such a sloppy science that you have to worry about copper contamination from a piece of razor-blade steel.
It is true that some metal foundaries use different melt practices, and there are some steels that contain copper. But if copper is in the steel you can bet its intentional, and serves a very specific purpose. When copper is added it is most often used to improve hardenability in complex alloy steels (for specific applications, which require high cost alloys).
Regular utility razor blades are very often made of plain carbon steel, which contain a maximum 0.6 weight percent copper.
A point of note is that when copper is in metallic form it is resistant to corrosion in seawater. Copper-nickel alloys are used exclusively for marine piping systems on navy ships.
The copper that is so damaging to saltwater tanks exists in the form of the cuprous ion. Not metallic copper. I'm not suggesting that you plumb your tank with copper. That would be dumb. But the amount of metallic copper that potentially exists in a chip of a razor blade is quite miniscule. Even then the metallic copper would have to be dissociated into cupprous ions. This is not likely at all.
There is no doubt common razor blades will rust. Rust is simply a sign that the metallic atoms present have oxidized to form a more stable compound. (they dont dissolve to any noticeable extent) Again, once a thick layer of oxide forms on the surface it will likely passivate the steel and prevent further oxidation. Corrosion slows down exponentially with the increasing thickness of the oxide layer, assuming the rust is not scraped off, exposing fresh new surface.
If it were me, I would get the thing out of my tank too, just because it doesn't belong there. But metallurgy is not such a sloppy science that you have to worry about copper contamination from a piece of razor-blade steel.
