On the influence of batch-to-batch microstructural variations on tool wear when machining C38 micro-alloyed steel

Journal article, 2024

Sustainable machining in micro-alloyed carbon steels necessitates a thorough understanding of microstructural variations and their subsequent influence on the machinability of different batches. This research investigates the machinability variation between two batches of a modified pearlitic-ferritic C38 micro-alloyed steel with a similar nominal chemical composition, through correlation of their tool wear responses at different cutting conditions to discrepancies in the microstructure and non-metallic inclusions between both batches. One batch of steel exhibits enhanced machinability for all investigated cutting conditions, showing remarkably different levels of wear development under similar cutting conditions and spiral cutting lengths. The different wear responses are then compared in association with the thermo-mechanical loads and microstructural discrepancies, where the less machinable batch is determined to have a lower ferritic volume fraction, higher hardness, and more abrasive nitrides than the other batch.