I believe my company can benefit widely from it, however I am not very familiar with it outside the basic concept, applications and benefits.

At this point we have a stamped piece of structural steel that requires embosses. Due to upcoming and imposing federal regulations, a very right radius will be required on these embosses so that a load path is not created to them.
Additionally, weight is always a concern in cars.


It is a very large company (Id rather not mention who) that is kind of shy on using new technology and would rather stick with the old stuff until the new stuff can utilized without hang ups. We can most certainly afford to implement a new hydroforming process, but not without much convincing.

I would not be responsible for the actual implementation, that is what manufacturing engineers are for. However I am curious as to the limitations of hydroforming. Can hot water be used to make the metal being formed more ductile (say 200*F)? Right now we are being forced to use a VERY expensive and VERY slow hot stamping process where sheet metal is heated in the die above the eutectic temp, formed and quickly quenched. Id like to get away from this.


If someone has a direction they can point me in, that would be great.

 

Depends on what type of material we're talking about. I work in the aerospace industry where hydroforming is a way of life.

Usually done on aluminum (2024), a part goes in the oven at 920 deg for x amount of time, x varies slightly according to thickness, to bring it to "O" condition, then quenched in water (Solution Heat Treating). This makes them very soft, you can easily bend it by hand. Then it goes in the freezer (0 deg) to keep it in "O" until needed by the machine operator. The operator then gets the part from the freezer and works it with the machine. If it is a part that requires more than one hydro process, it goes back in the freezer.

If not kept in the freezer, the part will "age", or naturally harden to T42 in about 96 hours. You can also artificially age the part (Precipitation Heat Treating) after the last forming stage by putting it back in the oven at about 350 deg. This will bring it to T62.

Hydroforming works well on aluminum, not so well on other materials, i.e. 17-7 stainless, titanium, etc. These require annealing at the machine before loading into the tooling. Sharp radii are avoided due to cracking.

Hope this helps.......

John

 

I don't believe 200*F "warm forming" has much effect on steel. That temp can be used with magnesium and slightly higher with aluminum, but, to my knowledge steel requires many 100s of *F to warm form.

I'd look at a design change if that were possible. I don't really see how to reshape the metal and not have the severe stresses without heating it. I don't believe conventional hydroforming will help.

If you assume you MUST heat the steel above eutectic temp, work on speeding up the current process. How are you heating the steel? Induction? How large is the heated/ worked area? Look at faster methods of heating to shorten cycle times. Perhaps a localized pre-heat while a part is waiting for the previous one to be processed would help.

How about explosive forming after the fast heating? Doing that in high volume production would be cutting edge, as far as I know, and probably not for a company shy on using new technololgy.

Google is your friend.