«

On Mon, 22 Dec 2003 13:39:35 +1300, Brendan wrote:

>>>Steel however does vapourise at about 1400C. Other metals - like aluminium
>>>and lead - much lower.
>
> Opps, that's the boiling point.

****ing hell: THE *MELTING* POINT.

I blame woger.

--

.... Brendan

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Two wrongs don't make a very good excuse...
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Note: All comments are copyright 2003, and are opinion only where not
otherwise stated, and always 'to the best of my reccollection'.

On Mon, 22 Dec 2003 16:31:19 +1300, Brendan
<corum.usenet@myrealbox....com> wrote:

>On Mon, 22 Dec 2003 13:39:35 +1300, Brendan wrote:
>
>>>>Steel however does vapourise at about 1400C. Other metals - like aluminium
>>>>and lead - much lower.
>>
>> Opps, that's the boiling point.
>
>****ing hell: THE *MELTING* POINT.
>
>I blame woger.

Whatever, it does something spectacular at that point and you don't
want to get any on you

Jerry

T.N.O. wrote:

> forensic analysis wrote:
>> For a sorted list of pure elemental melting and boiling points, try
>> http://www.science.co.il/PTelements.asp?s=BP
>
> Thanks for the link. reading it now.
>
>> Steel? An alloy, so it depends on the various component metals, but is
>> usually around 2500F (1370C)
>
> ok, hows about alumin(i)um or some other metals?
> The site lists boiling and melting temps, but doesnt really say about a
> gaseous state.



Gaseous state is the boiling point ..... and is the point at which the
vapour pressure equals atmospheric pressure.


Mercury is a good example of a metal with a very low boiling point and hence
a high vapour pressure ..... good for making mercury vapour light tubes
..... but not much good for humans to breathe.

AD. wrote:

> On Mon, 22 Dec 2003 10:42:04 +1300, T.N.O. wrote:
>
>>> The temperature provided above for Steel is an indicative melting point
>>> only ie solid to liquid, as there are many different alloy variants
>>> derived from an iron base. By heating steel from a liquid state a range
>>> of component elements will progressively evaporate until a residue is
>>> left, which would likely be carbon with a Boiling Point of 4827C.
>>
>> Interesting... so the bonding would break down with the heat then... and
>> you would get a more pure metal(well, more pure "what ever the hell is
>> the highest boiling" substance in it).
>
> Sounds like distillation. Compounds don't usually chemically break down
> when they evaporate - eg Water, Ethanol etc.
>
> I think (I don't actually know) the reason steel would break down as
> mentioned is that the carbon and iron etc aren't chemically bonded
> together - just mixed in together. This would presumably be the same for
> other alloys too.
>
> Cheers
> Anton


Yep, they're bonded OK. Iron Carbide ...... Bainite, Upper Troosite and
all that jazz.

On Mon, 22 Dec 2003 10:42:04 +1300, "T.N.O." <> wrote:
>
>Interesting... so the bonding would break down with the heat then... and
>you would get a more pure metal(well, more pure "what ever the hell is
>the highest boiling" substance in it).
>
The Romans used to refine lead by boiling it and sending it through
tunnels. Then they sent slaves down to scrape it off the walls. They
got through a lot of slaves.

Cheers,

Cliff
--

Christmas comes but once a year, thank the gods. I don't think
that I could cope with twice.

"AD." <> wrote in message
news...
> On Mon, 22 Dec 2003 10:42:04 +1300, T.N.O. wrote:
>
> >> The temperature provided above for Steel is an indicative melting point
> >> only ie solid to liquid, as there are many different alloy variants
> >> derived from an iron base. By heating steel from a liquid state a
range
> >> of component elements will progressively evaporate until a residue is
> >> left, which would likely be carbon with a Boiling Point of 4827C.
> >
> > Interesting... so the bonding would break down with the heat then... and
> > you would get a more pure metal(well, more pure "what ever the hell is
the
> > highest boiling" substance in it).
>
> Sounds like distillation. Compounds don't usually chemically break down
> when they evaporate - eg Water, Ethanol etc.
>
> I think (I don't actually know) the reason steel would break down as
> mentioned is that the carbon and iron etc aren't chemically bonded
> together - just mixed in together. This would presumably be the same for
> other alloys too.

Can be in solution or bonded.

You can find an interesting technical analysis document at
http://www.rigakumsc.com/journal/Vol...98/wheeler.pdf

"As iron can occur in a body centered cubic structure called alpha iron to a
face centered cubic structure known as gamma iron, their properties are
quite different. When carbon is added to iron it is known that it only has
slight solubility in alpha iron. Gamma iron, however, can hold up to two
percent carbon in solution at 1100 degree C. The alpha iron containing
carbon is called ferrite and the gamma iron containing elements in solid
solution is called austenite. When not in solid solution, the iron forms
iron carbide (Fe3C) which is extremely hard and brittle and is known as
cementite."

In article <>, "forensic analysis" <look@me>
wrote:

>You can find an interesting technical analysis document at
>http://www.rigakumsc.com/journal/Vol...98/wheeler.pdf
>
>"As iron can occur in a body centered cubic structure called alpha iron to a
>face centered cubic structure known as gamma iron, their properties are
>quite different.

I imagine their densities would be different as well. Face-centred cubic
would be denser than body-centred cubic. Would the denser form also be
the stable, lower-energy state? (That is, alpha could spontaneously turn
into gamma.)

>The alpha iron containing
>carbon is called ferrite and the gamma iron containing elements in solid
>solution is called austenite.

So THAT's what ferrite is. It was used as the core for medium-wave radio
antennas--something about its magnetic properties, I guess.

In article <rvxFb.14087$>,
gromit <> wrote:

>Gaseous state is the boiling point ..... and is the point at which the
>vapour pressure equals atmospheric pressure.

In other words, all liquids will boil in a vacuum--the liquid state is
unstable at zero ambient pressure.

And I believe at sufficiently high ambient pressures, the liquid and
gaseous phases actually merge into one, called the "supercritical"
phase. For instance, supercritical CO2 has become very useful as an
industrial solvent (for making decaffeinated coffee, among other things)
because all you have to do when you've finished with it is lower the
pressure and it evaporates, leaving zero toxic traces behind.

Lawrence
once read a story featuring a low-temperature phase of ice called "Ice
IV", which was supposedly stronger than steel

"Lawrence D¹Oliveiro" <_zealand> wrote in message
news:ldo-...
> In article <>, "forensic analysis" <look@me>
> wrote:
>
> >You can find an interesting technical analysis document at
> >http://www.rigakumsc.com/journal/Vol...98/wheeler.pdf
> >
> >"As iron can occur in a body centered cubic structure called alpha iron
to a
> >face centered cubic structure known as gamma iron, their properties are
> >quite different.
>
> I imagine their densities would be different as well. Face-centred cubic
> would be denser than body-centred cubic. Would the denser form also be
> the stable, lower-energy state? (That is, alpha could spontaneously turn
> into gamma.)

Well I suppose this is where we get into discussion on allotropy and phase
changes. and that's where it starts to get really interesting.

"Four changes occur in iron, which give rise to forms known as alpha, beta,
gamma and delta. Of these, a, b and d forms have the same atomic structure
(body centred cubic) while g -iron has a face centred cubic structure. Iron
can, therefore, be considered to have two allotropic modifications."

"Pure iron is one metal that changes from one of these crystalline
structures to another while remaining solid. It's BCC at temperatures up to
1,670 degrees F. But from 1,670 to 2,535 degrees F, it's FCC. Then from
2,535 to the melting temperature of 2,795 degrees F, it goes back to BCC."

Some useful online resources;

Steel structure http://www.key-to-steel.com/Articles/Art3.htm
General phases and structures
http://www.thefabricator.com/xp/Fabr...3/03web253.xml
Detailed steel phase diagram
http://www.sv.vt.edu/classes/MSE2094...es/kimcon.html

On Tue, 23 Dec 2003 16:33:35 +1300, Lawrence D'Oliveiro wrote:

> once read a story featuring a low-temperature phase of ice called "Ice
> IV", which was supposedly stronger than steel

Are you sure you're not confusing it with a high temperature form named
Ice-9? (Kurt Vonnegut Jr, "Cats Cradle")