I don't really know but my guess would be yes it will. I shot the Browning 50 and its got some power, I would think up to 2". In WWII the fighter pilots would shoot at Tiger tanks if they were on a road right under them and try and get their rounds to bounce up into the belly part where the the thinnest steel protection was.
THIS.. you could have a mild, thick steel and it would penetrate similar to a thin, harder steel. another thing to consider when discussing penetration is the angle.. the general stuff aside, i got out my USMC Machine Gun Leaders Course book and referenced some date which is where the following info comes from. i tried to copy and paste the tables but didnt work so i retyped it up. enjoy
My references for this information is Machine Guns and Machine Gun Gunnery MCWP 3-15.1 pg 4-60, so that you know im not talking out my rear.. this also list similar information for 5.56 and 7.62.
so depending on the type of steel you have, which im assuming is just a heavy plate steel not armor plate or face hardened, then i believe it will penetrate. i have fired thousand of rounds of 50bmg while in the USMC as a machine gunner and never ceased to amaze me at would that big round would do!!!
I don't doubt that it would penetrate. I shot a plate over 1" thick, 80 grade steel with .223 at 100 yards and it went through. That was standard ammo, not LAP.