For WW2 tank armour, what about the “rolling” that made the steel better than cast armour hardened armour and how… do you roll a steel plate?

Question

I’m familiar with the use of rollers to make glass panes but surely it’s not that?

In: Engineering

Answer 1

> I’m familiar with the use of rollers to make glass panes but surely it’s not that?

It is exactly that. There are two types of steel rolling: cold rolling and hot rolling, which work exactly as you’d imagine. Both realign the crystal structure of the steel to increase strength. Cold rolling produces a more polished finish and is a bit stronger, but the force needed is much larger than hot rolling, so very thick metal pieces (like rolled armor) were typically hot rolled.

Video of hot rolling in action: https://www.youtube.com/watch?v=6xnKmt_gsLs

Wikipedia on rolled armor that mentions hot rolling: https://en.wikipedia.org/wiki/Rolled_homogeneous_armour

Vendor discussing hot vs cold rolled products: https://www.metalsupermarkets.com/difference-between-hot-rolled-and-cold-rolled-steel/