Study on the transformative effects of cryogenic treatment on the mechanical, corrosion and machinability behaviour of mild steel parts

Abstract In this study, a modest attempt has been made to study the impact of deep cryogenic treatment on the mechanical, corrosion and machinability behaviour of the mild steel components. The cryogenic treatment was carried out for a time period of 48 and 72 h and the outcomes are compared with non-cryogenic treated samples. Taguchi L27 orthogonal array was framed by considering spindle speed (N), feed rate (f), depth of cut (d) and cryogenic treatment time (T) as input parameters and material removal rate (MRR), surface roughness (Ra, Rz) as output parameters. The hardness, wear resistance, impact test and salt spray corrosion test were also conducted to analyse the mechanical and corrosion behaviour. The optimization results exposed that 72 h cryogenic treatment significantly improved the MRR with reduced surface roughness compared to non-treated samples. Microhardness showed a remarkable improvement of 28.4%, and wear resistance increased by 35.2%, indicating enhanced durability and performance. The red rust formation is observed in all samples in corrosion test. Furthermore, cryogenic treatment positively influenced the microstructural properties of the material and increased the impact energy. The 72 h treated samples exhibited refined grain structures and reduced residual stresses. The 48 h cryogenic treatment also improved the properties of mild steel but not as like 72 h treatment. The outcomes of this study underscore the potential of deep cryogenic treatment, particularly for 72 h duration, in significantly enhancing the machinability, mechanical performance, and durability of mild steel.