Any steel that can be hardened to close to 50 Rockwell C will do, I made some targets out of vanadium-modified 4340 that were hung at a very busy range and endured an unbelieveable number of hits. I had the bar parted into a variety of thicknesses from 15mm to 30mm, 15mm didn't last long and 20mm took on a pronounced convex shape after a few weeks, but the greater thicknesses withstood thousands of hits.
The abrasion resistant steels thermomechanically processed to 500 Brinell are very popular because it is cheap steel, easy to find and weldable. Look for trade names like AR500, Hardox 500, HS500, MAS500, etc.