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Posted by Greyangel on November 27, 2005, 1:18 pm
Please log in for more thread options > Greyangel wrote:
>
> > I got a question about forging pattern welded steel. I've noticed
that
> > after doing the initial weld and draw at some point during the squaring
up
> > of the material I'll hit the layer edge just right and the layers will
split
> > open. Last time I was working a blade of layered steel I was able to
hammer
> > it back together and seemed to weld up just fine (not counting the one
> > really bad weld that killed the blade). I'm working another billet and
the
> > same thing happened. I was hammering the edge and everything was fine
and
> > then all the sudden it mushes open. Not deeply but just along the edge
of
> > the billet. Now Jim Hrisoulas in his book mentions proper forging
> > tempertures for pattern welded steel and I'm thinking that what I'm
doing is
> > getting it too hot to work? I took a K type thermocouple to to forge
this
> > last time to check tempertures after I was done forging and discovered
that
> > my forging temperture was at well over 2000F (which is where My reader
quits
> > reading....) I didn't realize I'd been working that hot. Will working
at
> > lower tempertures stop the delamination? Just to be clear I'm talking
high
> > carbon materials, not low.
> >
> > GA
>
> Sounds like a cold shut. WD-40 can yellow, that's the color. Back in the
fire
> at orange, no such thing as too much flux. When I first started making
cable,
> I'd take the billet and clamp it in the vise and try to 'unwind it' with a
big
> wrench. If it twisted 90 degrees without coming apart, it was a good one,
so I'd
> warm it back up and straighten it out. Then I got the powerhammer and I
stopped
> having delamination problems. By hand, I'd usually get about a dozen good
> strokes before it cooled off, with the LG I get about three times as many
> strokes before the iron is too cool. Patience, more fire, more flux. I
found
> that if you crown the face to be welded, you get better grab in the
center.
> Doesn't take much, just a little ramping from the center to the edge. This
helps
> the flux squeeze out as the pieces bond. Don't force it, use a bigger
hammer.
>
> Charly
Not saying all of the responces don't have valid points but what I'm talking
about happens after the welding has been done. I've already hammered it on
edge some and the welds appear to be stuck nicely - but then later when
shaping the bar, the edges will suddenly spread open some if hit just right.
Is that necessarily a bad weld or am I introducing conditions that will pop
open a good weld? This last billet was hammered from corner to corner to
sqare it up after the initial welding had made the stack kind of tilt to the
side and it showed no weakness between the layers at that time.
GA
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