THE EFFECT OF VARIOUS CUTTING ENVIRONMENTS ON TOOL WEAR AND ENERGY CONSUMPTION IN HIGH-FEED MILLING (HFM) OF TOOL STEEL

High-Feed Milling (HFM) is a highly productive method for machining tool steels. However, selecting the optimal cutting environment remains a critical factor for ensuring tool life and energy efficiency. This study compares five different cooling strategies – dry machining, conventional external fluid cooling, high-pressure internal fluid cooling, cooling via compressed air through the spindle, and external compressed air nozzle cooling – during the milling of X37CrMoV5-1 (300 HB) tool steel. The evaluation focused on flank wear kinetics (VBB), carbide tool degradation mechanisms, and total machine power consumption, followed by the determination of specific cutting energy and carbon footprint (CF1h). The results demonstrated that liquid cooling leads to premature tool failure due to thermal shocks and comb cracking, reducing tool life by more than 50% compared to gaseous media. Energy analysis demonstrated that liquid cooling increases machine power consumption by approximately 1000 W and doubles the specific cutting energy compared to dry machining. The study confirmed that for this HFM application, compressed air cooling or dry machining is an optimal strategy from both a durability and machining sustainability perspective.