View Single Post
  #26   Report Post  
Posted to rec.crafts.metalworking
Mike Spencer Mike Spencer is offline
external usenet poster
 
Posts: 164
Default Amazing Chinese forging video


Cydrome Leader writes:

There's no question they've made a huge flange of some sort, but if I
ordered 100 of them, would they vary at all? Would they even all be made
of the same type of steel etc. That's where I have questions about cottage
type industry.


Notice when they're doing the 2nd and 3rd round of forging the flange.
When the hammer strikes, it brings (what passes for) the set hammer --
the block of steel on a long stick -- down flush with the lip, never
goes too far and crushes the lip.

We never see the hammer driver but I'd say he's hot stuff, lots of
practice. Note that it's apparently a drop hammer, no powered stroke.
The hammer driver has to raise the tup just enough, reckoning on the
remaining heat at any stage, to get the blow just right.

Cool stuff, great teamwork.

I think it was mentioned that's a flange for a 48" pipe. At 100 PSI that's
90 tons of force trying to tear that thing apart. It has to be a sound
part and not just "close enough". Forgings still need proper heat
treatment, and from that video maybe they just bury it in dirt. It's not
really clear.


Is there any reason to believe that the workpiece isn't just mild --
low carbon -- steel? No special hear treating required if it's not
burned for forged too cold. I have a piece of oil rig pipe here that
is, I think, supposed to be good to 6,000 PSI, seems to be made of
kinda weird steel. 100 PSI is small potatoes.

--
Mike Spencer Nova Scotia, Canada