Tangential, but manganese steel/mangalloy/Hadfield steel was the first steel to be patented [1]. It hardens in response to impacts and is renowned for it's work-hardening properties.

> In addition to having the highest work-hardening properties, manganese steel is probably our toughest material. [2]

[1] https://en.wikipedia.org/wiki/Mangalloy#History

[2] T.B. Jefferson. Metals and How to Weld Them, 2nd Edition. page 255