Did they make steel-cased shell casings for U.S. WW2 75mm guns?

I found this steel shell casing at a place where a M3 Lee tank blew up. The markings on the primer say M31A2 1942 ILOP (or ILCP). Can anyone give me more info on this? Are steel cases more rarer than brass ones? Thanks.

In WW2 the US made a variety of steel cases for artillery calibers. Less common than brass but in the mainly used calibers also not too scarce.

That explains why I haven’t been finding any 75mm casings - probably because they have all rotted away and sadly I think that all the 75mm shell casings in that Lee were steel ,although I’ve been finding tons of brass 37mm M16 casings.

If I’m not mistaken, the M31 primer was meant for Supercharged H.E. rounds?