Anyone else playing with Dual Phase mat'l ?

[Hydroformer]

I recently launched a program using dual phase mat'l (HEDT590R). It's a fairly hefty TCF part (3.2mm). We stamp it from coiled sheet and it uses 1,870 of the available 2,000 tons our press can deliver. The moment of impact is truely impressive. We plan to run this tool during our share-holder meeting next month.

The material was not originally spec'd to be dual phase, it was introduced as an 'improvement' by the OEM. We found that we had to rethink the forming / extruding operations in the transfer tool. This material exhibits extreme work hardening and would prefer to be 'brought home' in a single motion. This however, is not entirely feasible.

We had to pay special attention to the forming planes and try not to re-bend in precisely the same plane but to create 'complementary' bends to achieve final geometry.

This was certainly a challenge as the mat'l change was made only 6wks prior to PPAP.

regards,

Hydroformer

 

[NickE]

Someone else must be cause when I was tech repping for a secondary house in detroit we used to see it come through once in a while. Had some really crazy properties IIRC.

Here is some info that I posted once before:

thread367-50834

And some mora:
thread330-113326

thread725-90957


enjoy.




Nick
I love materials science!

 

[Hydroformer]

Crazy properties, indeed...

I'm sure we'll see alot more of this material in the relatively near future. Currently, it's actually hard to come by. I've been competing (and losing) with a (for-dom) OEM to acquire stock. They cleaned out the mill when they learned we were purchasing the same grade. Another N. American mill is acquiring certification with these grades, but will not be online 'til fall. (I am NOT ordering production mat'l from Japan !!)

It does have some very attractive properties with regards to design possibilities, but tooling it up requires a bit of a shift in thinking. The strength and hardness change drastically as you (progressively) form the part.

I have a couple of deep extrusions involved that required modifications to suit the DP-steel. The final sizing punch is merely 'calibrating' and leaves a very hard (chrome finish) side wall.

I haven't seen it yet, but it would seem to be a very good candidate for hydroforming, providing the pre-forms aren't too severe.

A couple of good articles I've read recently on this:

http://www.metalformingmagazine.com/current/RaisingTheBar.pdf

http://ussautomotive.com/auto/tech/grades/dual_ten.htm

regards,

Hydroformer