Eric Stevens wrote:

On Wed, 07 Jul 2004 14:18:41 GMT, Seppo Renfors
wrote:



Eric Stevens wrote:

On Tue, 06 Jul 2004 01:18:46 GMT, Seppo Renfors
wrote:



Eric Stevens wrote:

On Mon, 05 Jul 2004 00:46:51 GMT, Seppo Renfors
wrote:



Eric Stevens wrote:

On Sun, 04 Jul 2004 01:02:50 GMT, Seppo Renfors
wrote:



Eric Stevens wrote:

On Sat, 03 Jul 2004 07:38:25 GMT, Seppo Renfors
wrote:
[..]
Anything can be welded at virtually any temperature by using pressure.
The Mini Minor crown wheel for the diff started off as a steel disc
cut off from a round billet. This was placed on a mould at the end of
a hydraulic ram, and the other half of the mould was on another
hydraulic ram. To form the crown wheel they were slammed together
under huge pressure - it made a very nice crown wheel - and fast!


You are confusing forging with welding.

Actually I referred to neither. I referred to the use of pressure only
as "merely by pressure" was your point.

But I was discussing welding. You seem to be confusing cold forging
with welding.


No, it appears that there is an issue of splitting hairs into quarters
again. At what point is something "melted"? It appears that it has to
also need the "melted" + "a length of time" to qualify as such.

So if you want to go pick up one of those crown wheels, with your bare
hands immediately AFTER it is made - the same piece of metal you put
into the die BEFORE the event with your bare hand - well go for it,
you say it is "cold" after all!


As in so many other areas, your knowledge of metallurgy appears to be
unique.

So "unique" that you cannot find a hole in the arguments I put to you,
instead you find a need attack me personally not only on this but also
"in so many other areas" - your mere assertions amounts to nothing.
Remember the last time you resorted to something like this - can I
just mention "slide rule" to remind you, hmmm?

The question then was whether 43/7 equalled 18/3. I said it didn't.
You insisted it did.

I can no longer recall the number, and care even less - FACT is that
they are close enough to being equal. So in ancient times if they used
**** houses as one set of measurements, and yard arms for the other,
they are close enough considering no fractions were used - a
measurement for which an APPROXIMATE conversions was given - a
measurement for which that level of accuracy is more than adequate.

You came unstuck on that one and still are all at sea with it - as
your recent argument about a nautical mile and "great circle"
circumference measure, which is ANY circle around ANY part of the
globe, when the specific circumference given was at the equator -
nowhere else. Something that varied sometimes by a few meters - like
WOW!!

I think I abandoned that argument at the point
when you effectively resorted to arguing that 'approximately' is
identical to 'exactly'.

When ONLY approximates were given then only an approximate can be
VALID and can NEVER mean your petty hair splitting "accurate" claimed
to be achieved FROM an "approximate" - it can't. Simple as that. You
are resorting to the same sort of nonsense game again!!

Apart from that, those forging blanks were NEVER hot enough to melt.

Prove it!

It was NOT NECESSARY that they be melted for them to be reformed.

Prove it! Remember you are talking about a fraction of a second in
time as well.

One
of the reasons for forging is to presever the original grain flow of
the lank and that would be lost if the blank was melted.

(I have no idea what relevance "long, limp, and straight" (lank) has
to anything here so I'll ignore the term.)

Not true for the particular example given - other similar items are
cast and machined in the traditional manner. Again you only make
totally unsubstantiated assertions and do not speak about the reason
WHY at all! You know, that thing that makes it work and proves your
claims. Haven't you found it on the net yet?

So let is look at this "grain flow" claim:

This is advertising spoof for a Japanese made Golf club:
"Grain Flow Forging exceeds the conventional forging process by
repeating the high pressure compression process to ensure a tight
uniform grain structure through the clubhead. Each head is forged from
one piece ensuring an uninhibited grain flow through the head and
neck."

So there of forging and "grain flow forging" - apparently... but - no
hammering - hydraulically pressed from a single small billet - ie mass
produced by machines where SPEED of production is of prime importance.
Another source says:

"Forging refines the grain structure and improves physical properties
of the metal. With proper design, the grain flow can be oriented in
the direction of principal stresses encountered in actual use. Grain
flow is the direction of the pattern that the crystals take during
plastic deformation."

So a lot of gobbledegook in reality if compared to your "expert" claim
of "preserves the original grain flow" and "cold". Which is a load of
nonsense for the example I provided - it isn't important. What IS
important is unit speed of production and therefor unit cost of the
production. So slam two dies together and form a crown wheel for a
Mini in a fraction of a second at tremendous pressures like up to
some 50,000 tons and tell me no part of it did melt at any stage! Oh
and you call this "cold forging", when the more correct term is
"Open-die forging" or "Closed-die forging" or even "Two stage
closed-die forging". There is nothing "cold" about it.

Oh and to finish off with the golf club:

"Ageing the head at elevated temperature optimizes strength and
softness." Oh well...... so much for the "cold"....


--
SIR - Philosopher unauthorised
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The one who is educated from the wrong books is not educated, he is
misled.
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