Alright guys, need some help here.
I am working in a Mori Duracenter 40 taper with Inconel 625 (approx 30 HRc), machining a 1" thick flat on the end of a 2" round bar. I have tried using a Garr 3/4" VHM Endmill (125-175 sfm @ .003-.0035 per flute), an Iscar T490 ELN D.75-3-W.75-08 with T490 LNMT 0804 P NR IC330 inserts (80-110 sfm @ .003-.004 per flute) and each one failed. I was doing .45" width cut, going from .100 deep to .500 deep then back to .100 deep (cutting across the part). have to cut the flat to 2.0" long. With the T490 cutter, I did it in two depth cuts with the first being at Z of .725" absolute ( Z0. is the center of the 2" diameter), the 2nd pass was set to Z .510" (which I didnt run due to the way the first depth cuts were going). The only thing I have working right now, and I say that loosely, is using an Ingersol 12J1E1581R01 4fl cutter with AOMT180508R IN1030 inserts, but the inserts are barely lasting 2 parts. Also I am machining this at .15" depth then .100" depth, running the length of the flat, not width.
I have an Iscar FINISHRED endmill (EFSI-E44 500-1.0W500CF IC900) to try, but want some ideas before i waste another tool on this job.
Attached is a pdf of the part, no dimensions though. the main body is 2.00" dia, the thickness of the flat is 1.00" and is 2.50" long.