Update-
So, Alabama damascus lists the following for their steel types:
Material = (4) layers 5160, (3) layers 203E, (3) layers 52100, (3) layers 15N20 folded 5 times for 416 layer damascus
Below is a chart from zknives comparing 3 of the 4. They had no listing for 203E
And their description of each -
15N20(Bohler-Uddeholm) - Bandsaw steel by design. Very tough, similar to AISI L6 tool steel, except for the missing Chrome. 15N20 is used...