Cold Rolled Skin

[Isley]

I noticed the AEB-L I ordered was cold rolled and in researching the matter came across a YouTube video of a machinist discussing the difficulty of maintaining dimensional stability with such steels due to the "skin" formed during the cold roll process. Also, in a forum post I found by Aaron Gough, he described the steel (AEB-L) flexing heavily while grinding one side, then evening out after grinding the other side. This is the first time I've used this steel so my little initial test could (probably) mean absolutely nothing, but I decided to profile and drill one, the other I profiled - drilled - and plate sanded through the "skin". The first has moved rather erratically throughout processing but not outside correctable limits, while the later has remained true through out. The stock for both was .082. Does anyone know if there is merit to this notion, or similar experience?

 

[MBB]

If you do an initial stress relief cycle (1200 F for 2 hours) before you even profile (on the bar itself), most of these issues go away as they are a result of stored internal stresses post rolling.

 

[Big Chris]

As stated above cold rolling imparts a lot of stresses into the steel.
Personally, I would profile, drill, and then clamp all your blades in a big stack to do the stress relief cycle.

 

[Isley]

OK, I wondered about doing something like this in a stack, like I've seen done at the industrial level facilities. Maybe a dumb question but what kind of clamp should I use for such an operation. Large standard C-clamps?

 

[Big Chris]

I use small C Clamps or Kant Twist clamps.

 

[P.Brewster]

OK, I wondered about doing something like this in a stack, like I've seen done at the industrial level facilities. Maybe a dumb question but what kind of clamp should I use for such an operation. Large standard C-clamps?

Most C-clamps are painted, so you'll need to burn or strip off the paint, or deal with the stink when they go into the oven. Kant-twist clamps are nice because they aren't painted.

 

[Isley]

I have some half baked from straightening operations, so no biggie to torch the paint.