The GEMLUX® Advantage Information
The GEMLUX® Advantage
Some Technical Details
The corrosion of stainless steel is counteracted by passivation.
Without passivation iron or iron oxide exists on the surface of
stainless steel. When any machining or fabrication operations
are performed, the condition is worsened. Aside from iron being
deposited by tooling, it is also being entrapped underneath the
“smeared skin” created by the mechanical operation. This is why
GEMLUX® processing is so valuable.
Surface passivation by nitric acid immersion only attacks iron at the
surface. This only partially solves the problem. The remaining iron
under the skin will now corrode both inwardly and outwardly.
The inward corrosion is known as I. G. A. or intergranular attack.
The results are metal fatigue and surface corrosion. Any applications
requiring a clean environment such as gas or liquid valves
and pumps, bearings, vacuum systems, or fuel supplies would
be subject to detrimental effects without thorough passivation.
GEMLUX® processing resolves this problem entirely. Surface
contaminants and the false skin which entraps iron are removed
electrochemically. the surface that remains after processing
is positively the cleanest, most passive surface possible. The
microfinish is lowered and dimensions with close tolerances do
not pose a problem. The rate of
metal removal is controllable with this process.
The "E.P." Process
Chromium, which is a component of stainless steel, is electrochemically
enhanced on the product surface. The chromium-to-iron ratio on
the surface of the stainless steel is transformed through iron removal
from a 1:6 to a 4:1 ratio. The chromium oxide layer that is formed is a
homogeneous constituent of the metal. It cannot delaminate or peel
and is extremely corrosion resistant.
A stainless steel piece is placed on a copper rack and immersed into
an electrolytic acid bath. This proprietary GEMLUX® bath consists
primarily of phosphoric and sulfuric acid. The bath temperature may
range from 120° - 180° F. Electricity is run through the rack (the anode)
and the work pieces. At this point, the negatively charged cathodes
draw the iron off the surface of the stainless steel.
In most electropolishing solutions, the iron ions are dissolved into the
acid solution or dumped to the bottom as sludge, and as the iron
builds up, quality and consistency decrease. This does not happen
with GEMLUX®. We actually plate the iron to the negative cathode
and remove the contaminating iron on a daily basis. This produces a
consistent finish on each stainless steel product.