by this time i try to develop a bifurcation of a penstock and I want to make a production drawing for the developed view of each sheet metal part. is there anybody had an expreience to do it using inventor?thanks Guys

If by 'bifurcation' you mean a section view, yeah!
Just open a new .idw, place your view, then section it using the 'section view' command in the 'place views' tab. Should be fairly simple ;)

by the way that is not my point buddy, what I mean is unfold view of the each plate that construct the bifurcation. thankyou

That, BUDDY, I do not know.
I suggest autodesk support or just keep on googlin' for a solution.

I haven't done so however, I saw sheetmetal broken down into parts.
 
Try this link for a pro.
 
http://home.pct.edu/~jmather/content/CAD238/AutoCAD_2007_Tutorials.htm