2026 Volume 70 Issue 2 Pages 99-104
To improve the production efficiency of steam turbine blades, this study was performed to experimentally examine the relationship between cutting speed and tool wear before and after heat treatment of four types of stainless steel (SUS Cr9, SUS Cr12, SUS 13Cr, and SUS 15Cr) used as turbine blade materials. The sudden increase in peripheral flank wear of SUS 9Cr before heat treatment was attributed to the high affinity of Ti present in both the endmill coating and the additive element of stainless steel, which facilitates welding and increases the cutting point temperature, exceeding the heat resistance temperature of the coating. The sudden increase in peripheral flank wear of SUS15 Cr before heat treatment was attributed to the fact that the combined addition of Cu+P to the workpiece accelerates wear and raises the cutting point temperature, which exceeds the heat resistance temperature of the coating. After heat treatment, the peripheral flank wear increased at low and high cutting speeds, and the peripheral flank wear decreased in the intermediate cutting speed range. The greater flank wear at low cutting speeds was attributed to the fact that the workpiece surface became harder due to heat treatment, resulting in a greater impact on the cutting edge. A machining condition map showing the relationship between cutting speed and cutting volume, with a focus on productivity, is proposed.
