I'm not sure what you thought was contradictory within that quote. I thought it was reinforcing a single idea? I was pushing back on the idea that very high reduction ratios keep causing higher and higher strength. There is a pretty low limit to the amount of deformation you can make in steel and aluminum before you wreck the metal. You need to keep resetting the cold work via annealing to be able to keep forming the metal. Cold work is just done as the final pass with a very limited final dimensional reduction in rolling.
I'm not saying cold working doesn't happen, or doesn't affect strength. It certainly does. I'm pushing back on the idea that forging creates superior strength via grain flow. One of the sibling comments pointed out the MIL spec materials handbook[1] where he found some materials that do exhibit a strength dependency on grain direction. That is interesting.
That seems to be the exception rather than the rule. If you go to page 3-220 in that spec, they show 5052 Aluminum in varying degrees of cold work (H32, H34, H36, and H38), where higher degrees of cold work have higher ultimate and yield strengths, but the L vs LT directions are identical in many cases, or 1 different. That goes against the general idea that forging grain flow creates superior strength in general.
I'm not saying cold working doesn't happen, or doesn't affect strength. It certainly does. I'm pushing back on the idea that forging creates superior strength via grain flow. One of the sibling comments pointed out the MIL spec materials handbook[1] where he found some materials that do exhibit a strength dependency on grain direction. That is interesting.
That seems to be the exception rather than the rule. If you go to page 3-220 in that spec, they show 5052 Aluminum in varying degrees of cold work (H32, H34, H36, and H38), where higher degrees of cold work have higher ultimate and yield strengths, but the L vs LT directions are identical in many cases, or 1 different. That goes against the general idea that forging grain flow creates superior strength in general.
[1]http://everyspec.com/MIL-HDBK/MIL-HDBK-0001-0099/MIL_HDBK_5J...