Refractory Metal Bend Tables

[13]

DOes anyone know of any literature that has been published on bend tables for sheet fabrication of refractory metals, most interested in Molybdenum, Tungsten, Tantalum? I have searched the web far and wide and have not really come up with anything. I am performing my own tests to develop a correlation that we can use with good accuracy, but it is a very lengthy and tedious task.

Any input would be appreciated.

Thanks!

 

[btrueblood]

Tungsten is not cold workable, it behaves as a brittle material at RT.

 

[13]

I realize that. We bend after heating.

 

[btrueblood]

Never heard of bend tables for hot working, but then am no expert. For hot working we generally just specify to heat above the hot working temperature, bend, then anneal if necessary. We also have/had rules for forged products that limit the number of furnace cycles to control oxidation damage. Typically, metallurgical analysis of sample parts is done as well to verify details of grain size and absence of cracking. Moly does suffer from a hot-shortness if I recall correctly. There is good info in ASM handbook, you can also contact Teledyne Wah-chang(sp?) and other alloy providers (GE?) for more info.

 

[13]

Basically metals "stretch" when bended. Therefore the fabrication dept uses bend tables or bend "subtractions" or "setback" numbers when calculating the setup for a bend. These numbers are well established for steel, stainless, copper, aluminum, etc.
They are not however established for refractory metals. I just didn't know if there was PUBLISHED data regarding this matter. I have searched but with no luck. I work for a major metal producer and fabricator and no one here has had any luck either. Just rule of thumb standards.

Thanks for all the response! Keep it coming!

 

[btrueblood]

13, yeah, I've seen bend tables for cold working alloys. But I've never seen such tables for any alloy under "hot" conditions - do you have data for bending stainless steels at 800F? Just curious, it's been awhile since I had to use same.

Re-reading your second post, it's not clear to me: is the tungsten red hot as its being bent? If not, you are actually cracking the tungsten to achieve permanent deformation.

 

[metengr]

Here is some information on formability temperature of tungsten from Principal metals. You might want to contact them directly for additional information on other refractory metals;

http://www.principalmetals.com/prime/step1.asp