At 11:48 8/7/99 , Hans van Veluwen wrote:
>text: "Bill of rights". Yeah, right, Bill. Anyway, this is what it has to say
>about Titanium:
>
>/***********************************************************
[MicroSlop Quote Snipped Off]
[Now where did I put that CRC Handbook of Chemistry and Physics. I know
it's being used as a doorstop somewhere around here. Oh well.]
Hmmmm, Encarta is *grossly* innacurate about its solubility in water.
Quoted from the Titanium Metals Corporation data sheets on Titanium's
properties):
----------------------------------------
RESISTANCE TO WATERS
FRESH WATER - STEAM
Titanium resists all forms of corrosive attack by fresh water and steam to
temperatures in excess of 600 degrees F (316 degrees C). The corrosion rate
is very low or a slight weight gain is experienced. Titanium surfaces are
likely to acquire a tarnished appearance in hot water steam but will be
free of corrosion.
Some natural river waters contain manganese which deposits as manganese
dioxide on heat exchanger surfaces. Chlorination treatments used to control
sliming results in severe pitting and crevice corrosion on stainless steel
surfaces. Titanium is immune to this form of corrosion and is an ideal
material for handling all natural waters.
SEAWATER
GENERAL CORROSION
Titanium resists corrosion by seawater to temperatures as high as 500
degrees F (260 degrees C). Titanium tubing, exposed for 16 years to
polluted seawater in a surface condenser, was slightly discolored but
showed no evidence of corrosion. Titanium has provided over thirty years of
trouble-free seawater service for the chemical, oil refining and
desalination industries.
Exposure of titanium for many years to depths of over a mile below the
ocean surface has not produced any measurable corrosion (Table 5). Pitting
and crevice corrosion are totally absent, even if marine deposits form. The
presence of sulfides in seawater does not affect the resistance of titanium
to corrosion. Exposure of titanium to marine atmospheres or splash or tide
zone does not cause corrosion.
EROSION
Titanium has the ability to resist erosion by high velocity seawater (Table
6). Velocities as high as 120 ft./sec. cause only a minimal rise in erosion
rate. The presence of abrasive particles, such as sand, has only a small
effect on the corrosion resistance of titanium under conditions that are
extremely detrimental to copper and aluminum base alloys.
(Table 7). Titanium is considered one of the best cavitation-resistant
materials available for seawater service (Table 8).
----------------------------------------
This means you need not fear corrosion of the 3ti or 4T Titanium body if
you accidentally drop it into the ocean and cannot retrieve it for a decade
or so. You might have to replace everything else, but the Ti part of it
will survive just fine. For those of you who cannot bear being without
your beloved 3Ti or 4T, you can resume bathing with it.
Encarta didn't mention one of its major uses in the electronics industry
either: tooling in and around soldering systems. Tin/lead solder will not
"wet" to it. If you accidentally drop your 3ti or 4T into a vat of molten
solder (as in when you are photographing the details of a wave soldering
process) instead of the ocean you need not fear any solder adhering to it
when you finally retrieve it. Hand retrieval is not recommended in this
situation as a vat of eutectic tin/lead solder is about 240-250C (approx
465-480F). Only the OM-1 through 4 owners need fear anything as it will
wet to the brass. Removal of solder well wetted to a metallic surface is
all but impossible without grinding it off.
-- John
< This message was delivered via the Olympus Mailing List >
< For questions, mailto:owner-olympus@xxxxxxxxxxxxxxx >
< Web Page: http://Zuiko.sls.bc.ca/swright/olympuslist.html >
|