[TheForge] Heat treat for Titanium

[Hochewa at aol.com]

To All,
I make my Titanium strikers from CP (Commercially Pure), Grades 1, 2 or  3.  
The actual grade does not matter.  These alloys are not heat  treatable.  I 
have not tried Ti 6-4 or any of the treatable alloys because  of the strings on 
Ti-flu
The trick to a lot of sparks is a good sharp flint and an oxide free  surface.
And to re-inforce a few things:
Carbon steel is relatively unique in the metastable eutectoid decomposition  
that yields a very hard structure, martensite, when quenched properly.
Solution annealing is the act of putting all or at least most of the  
alloying elements into solution, think salt in water.
Quenching from the solution annealed state usually yields a relatively soft  
structure that must be age hardened to precipitate the alloying elements out 
as  desired second phases that now make the material "harder".
Harder may not be better for flint strikers.  The spark is actually a  fine 
shaving of the striker that ignites in the air because of friction as are  all 
grinding sparks.
Annealing Titanium in hydrogen gas, H2, does not do nearly the damage as  
annealing it in an atmosphere that contains a little ammonia.  It is  the H, not 
the H2 that does most of the damage.  Ti is annealed in a  vacuum or a very 
dry inert atmosphere because of oxidation.
Etching Ti or electropolishing Ti creates nascent Hydrogen  (H) at  the 
surface which diffuses into the material and embrittles  it.
The 10K*C TIG arc decompose water vapor into H and O2.  That  embrittles it 
by absorbtion in the weld puddle.
 
Hochewa
 
 
In a message dated 9/5/2006 4:31:37 PM Eastern Standard Time,  
schade at acegroup.cc writes:

seems  like a lot of bother. I have forged small amounts
of 3/4" round titainium.  I never had a problem with "elephant skin".
Also I think the "cp" means  "commercially pure" but I really don't
know what that  means.