Years ago I cut a similar size steel shaft(don't know the grade, but someone thought it might be an axle from a railway wagon), never again, got about 3/4 the way through and there was a click, the saw stopped, but the belt slipped. The cut had closed up and jambed the blade, I managed to get the shaft with the blade out of the saw, fit another blade and restart the cut from the other side. I can't remember how long the cut took, but it was a lot quicker than an armstrong hacksaw(done that too).
Ian S C