In the present time, advanced high strength steel (AHSS) has secured a dominant place in the automobile sector due to its high strength and good toughness along with the reduced weight of car body which results in increased fuel efficiency, controlled emission of greenhouse gases and increased passengers’ safety. In the present study, four new advanced high strength steels (AHSS) have been developed using three different processing routes, i.e., thermomechanical controlled processing (TMCP), quenching treatment (QT), and quenching & tempering (Q&T) processes, respectively. The current steels have achieved a better combination of the high level of strength with reasonable ductility in case of TMCP as compared to the other processing conditions. The achievable ultrahigh strength is primarily attributed to mixed microstructure comprising lower bainite and lath martensite as well as grain refinement and precipitation hardening.

Multiple response optimization of the machining of 17-4 PH stainless steel material, which is difficult to process with traditional methods, with EDM was made by Taguchi-based grey relational analysis method. Surface roughness (Ra), material removal rate (MRR), and electrode wear rate (EWR) were the responses, while current, pulse-on time, pulse-off time, and voltage were chosen as process parameters. According to the multi-response optimization, the experiment level that gave the best result was A1B2C2D2. Optimum machining outputs were found as A1B3C1D1 using the Taguchi method. As a result of the Taguchi analysis and ANOVA, it was determined that the significant parameters according to multiple performance characteristics were current (56.22%) and voltage (22.40%). The surfaces of the best GRG and optimal sample were examined with XRD, SEM and EDX analysis and the effects on the surfaces were compared.