Now days I only ever use carbide insert tooling has the removal rates are so much better than HSS. When first started using them I wasn't too impressed until someone far more experienced using lathes told me I was cutting far too slow and shallow.
For Aluminium I have CCGT tooling using HA or AR inserts and Couldn't believe the difference and time savings when I eventually plucked the courage to try deeper than steel. Seemed the more I pushed the better it got( up to a point obviously)
I rough cut Alu at 0.3mm/rev but slightly lower DOC @ 3.5 and It certainly hasn't hurt my little Boxford.