Announcement

Collapse
No announcement yet.

Metal Warping?

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • #16
    If you have the bit of sheet it came out of you might try cutting one at 90 degrees to the first.
    Mark

    Comment


    • #17
      Originally posted by boslab View Post
      If you have the bit of sheet it came out of you might try cutting one at 90 degrees to the first.
      Mark
      Hi Mark,

      Should I expect a different result if cut at a 90 deg angle? Is it remotely possible that internal stresses run at a different angle? What should I be looking for or what different results should I expect or observe?

      Harold
      For those having fought for it, Freedom has a flavor the protected will never know.
      Freedom is only one generation away from extinction.

      Comment


      • #18
        You do get different properties depending on rolling direction, it looks like the peice is in the rolling direction, it's rolled, wound on a coil, then pulled from the coil and passed through a straightener, on thick stuff it can be just a pyramid set up, 2 rolls one side and a roll in the middle the other side and sheared into sheet size, the straightener puts just enough deformation to get the sheet flat, when you slit a straightened sheet it often reverts to the curve that was present before the straightener.
        Cutting at 90, ie across the coil or 90 degrees to rolling often limits this, there is a tendency to bow but across a narrow strip it's not noticeable.
        Cutting at 45 degrees to the rolling axis often leaves a twist.
        Steel is the same, there are 3 axis, the steel industry call them R1, 2 and three but all the plants I went too call R1 rolling, R2 is 90 degree to rolling and R3 45 degree to rolling displaced in the rolling direction, we did come up with a R4 which was 45 degrees the other way or rolled, the steel is tested in all these directions with tensile test pieces being cut in these directions, the results are usually quite different so manufacturers can cut pits of car out of one sheet with different mechanical properties, same applied to Ali sheet, not saying that's universal but fairly in Europe. Eg land rover, jaguar and so on
        Mark

        Comment


        • #19
          Many years ago, when I was building a steam locomotive, I found that the BMS 1 1/4" x 1/4" that I was using for the connecting rods had lots of built in stress. I was horrified to see how it peeled open as I cut down the side of a 230mm piece. The cut opened out to 10mm as I proceeded down the edges. Fortunately this only happened as I roughed it out, it stayed straight during the subsequent machining.

          Comment


          • #20
            Originally posted by boslab View Post
            You do get different properties depending on rolling direction, it looks like the peice is in the rolling direction, it's rolled, wound on a coil, then pulled from the coil and passed through a straightener, on thick stuff it can be just a pyramid set up, 2 rolls one side and a roll in the middle the other side and sheared into sheet size, the straightener puts just enough deformation to get the sheet flat, when you slit a straightened sheet it often reverts to the curve that was present before the straightener.
            Cutting at 90, ie across the coil or 90 degrees to rolling often limits this, there is a tendency to bow but across a narrow strip it's not noticeable.
            Cutting at 45 degrees to the rolling axis often leaves a twist...........................
            Mark

            Hi Mark,

            I really didn't know the particulars but I suspected, when you suggested trying a different cut, that bowing may have something to do with the way the metal was finalized. That's interesting. Thanks for pointing that out.

            Harold
            For those having fought for it, Freedom has a flavor the protected will never know.
            Freedom is only one generation away from extinction.

            Comment

            Working...
            X