Modelling for cost and productivity optimisation in sustainable manufacturing: a case of dry versus wet machining of mould steels

Under certain conditions, dry machining has been known to offer improved efficiency. To determine the effectiveness of dry machining in the production of steel, it is necessary to identify optimal machinability conditions for commonly used mould steel products and their economic aspects. The present study expands on a comparative analysis of dry and wet optimum machinability conditions for universally used industrial mould steels; SF-5, SF-2312, SF-2-000, and SP-300. In this study, the newly developed MICO (Machining Inventory and Cost Optimisation) tool was used to determine the machining related production cost and identify optimal productivity parameters for these mould steels. The MICO analysis presented utilised the established tool wear equations for both dry and wet milling conditions to determine machining costs and productivity. The results of the case study revealed that during dry machining, materials with lower-hardness steels (SF-5 and SF-2312) saw increased productivity and a reduction of total costs with optimal conditions. In wet milling operations, the added use of lubrication increased costs by 5–8% at optimal machining conditions. The overall cost was found to be more sensitive to the influence of lubrication than were the tool usage and inventory costs.