Surface morphology evaluation of hardened HSLA steel using cryogenic-treated brass wire in WEDM process

Abstract

Surface morphology of a high strength low alloy steel is analyzed on wire electric discharge machining (WEDM) process with a cold-treated (CT) brass wire. Cold treatment process is carried out at − 70 °C for 24 h to refine the microstructure of brass wire for smooth discharge energy during machining process. Fractional factorial design is used to measure the response of recast layer thickness (RLT), wire material infusion (WMI), and micro-hardness (MH) of hardened HSLA steel. CT brass wire, servo voltage (SV), pulse on time (Ton), pulse off time (Toff), wire tension (Tw), and flushing pressure (Fp) of deionized water are selected as input process parameters. Analysis of variance (ANOVA) is performed to test the adequacy and significance of the developed mathematical models. Ton is observed as the most effective input process parameter followed by Toff and CT brass wire. Low-energy parameters with CT brass wire exhibits results with reduced RLT and WMI on machined surface as compared to NCT brass wire. CT brass wire is less wear off with respect to NCT brass wire while machining workpiece at same input process parameters.