CHROME EXTRACTED FROM STAINLESS STEEL
CHROME EXTRACTED FROM STAINLESS STEEL
(OP)
WE ARE RIDING PLASTIC PARTS ON 304/304L S.S. RODS AND PLATES. WE DISCOVERED A BLACK RESIDUE ON THE PLASTIC (ERTALYTE) PARTS. THIS WAS IDENTIFIED AS CHROME TURNED BLACK BY CHLORIDE (MOST LIKELY THE CUTTING COOLANT). IS CHROME LEAVING THE S.S. NORMAL FOR 304? SHOULD WE BE USING A DIFFERENT S.S., OR SHOULD WE TREAT/COAT THE PARTS? THANKS FOR ANY HELP.





RE: CHROME EXTRACTED FROM STAINLESS STEEL
It is a little surprising the plastic is hard enough to do this. Is there some third party abrasive around?
RE: CHROME EXTRACTED FROM STAINLESS STEEL
RE: CHROME EXTRACTED FROM STAINLESS STEEL
RE: CHROME EXTRACTED FROM STAINLESS STEEL
The most commonly available grade that is a notch above 304 is 316L, which containes 2%Mo & costs a bit more.
Next above that would be the duplex stainless (magnetic) 2205 (S32205/S31803)with 3%Mo, about 40% more expensive than 316L. 2205 is also somewhat more wear resistant that either 304 or 316L.
A grade probably far more than you need would be AL-6XN (UNS number N08367, ASTM B 688 plate, B 691 bar) with about 6.2%Mo.
In theory there are a zillion alloys you might consider, but the above grades can actually be purchased in small quantities from steel distributors.
James Kelly
www.rolledalloys.com