# Principles and Characteristics of Different EDM Processes in Machining Tool and Die Steels
## 4 Research in EDM of Tool Steel  
In this section, the studies dealing with tool steels in EDM processes are reviewed based on the classification scheme below.  
_Type of EDM process._ The relevant studies are classified according to the EDM process used to machine the tool steel workpiece are as follows:  
D-S Die sinking EDM  
W Wire EDM  
Micro-EDM  
P-M Powder-mixed EDM  
D Dry EDM  
**Objective function:** The following objective functions are reported in the current relevant literature:  
_Objective 1: Performance measures in EDM of tool steels_  
_Objective 2: Effect of EDM process on the surface integrity_  
_Objective 3: Development of new methods and methodologies_  
_Objective 4: Modeling and Simulation of EDM process_  
_Objective 5: Electrode material and shape in the EDM of tool steel_  
_Objective 6: Combined and hybrid processes of tool steel_  
_Objective 7: Dielectric fluid research_  
_Objective 8: Other objective functions_  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Different Grades and** & **Composition (Weight** & **Properties** \\
**Operations** & **\%)** & **This grade has high abrasive resistance, adhesive wear resistance, and compressive** \\ \hline
**DIN 1.2379** & C 1.50, Si 0.30, Cr 12.0, Mo 0.80, V 0.80 & strength. It also has good toughness and good dimensional stability [183]. \\
**DIN 1.2738** & C 0.4, Mn 1.5, Cr 1.9, Ni & This grade has good toughness, wear resistance, stability in hardness, and high hardenability. \\
**DIN 1.2714** & C 0.50–0.60, Si 0.10–0.40, Mn 0.65–0.95, Cr 1.0–1.2, Mo 0.45–0.55 & DIN 1.2714 has good hardenability and uniform hardness over sections with big dimensions. Furthermore, it has good strength and toughness in addition to its tempering resistance and dimensional stability [187]. \\
**DIN 1.2080** & C 2.00–2.35, Mn 0.60, Si & DIN 1.2080 is high-carbon/chromium tool steel. It has very high wear resistance and compressive strength. It can be hardened with a very slight change in size. \\  & C 0.38–0.43, Si 0.15–0.35, Ni & AISI 4340 is a heat-treatable and low-alloy steel containing chromium, nickel, and molybdenum. It has high toughness and strength in the heat-treated conditions [189]. \\
**AISI 4340** & Mn 0.6–0.8, P 0.035, S & steel containing chromium, nickel, and molybdenum. It has high toughness and strength in the heat-treated conditions [189]. \\
**Die sinking EDM [188]** & C 1.64, Cr 4.80, W 10.40, Mn 0.60, Ni & This material has the ability to maintain its strength and hardness level under extremely high cutting temperatures. \\
**S390** & C 8.00, V 4.80, Mo 2.00, Ni 0.60, Mn 0.30 & strength and hardness level under extremely high cutting temperatures. \\ Wire EDM [148]** & C 0.36 0, Si 0.28, Mn 1.52, Mo 1.52, Mo 0.22, Ni 0.95, Al 0.021 & It is hardened and tempered plastic mold steel. There is reduction of hardness in the center of large sizes due to the Ni-addition. \\
**M238 HH** & C 0.008, S 0.001, Cr 1.88, Mo 0.22, Ni 0.95, Al 0.021 & There is reduction of hardness in the center of large sizes due to the Ni-addition. \\
**Die sinking EDM [74]** & C 1.4, Si 0.4, Mn 0.4, Cr & This grade has very good ductility, high abrasive/adhesive wear resistance, and high compressive strength. Moreover, it has good dimensional stability during heat treatment, good through-hardening properties, and temper back resistance [191]. \\ \hline \hline \end{tabular}
\end{table}
Table 1: Cont.  
Using this classification scheme, Table 2 chronologically lists the studies for different grades of tool steel machined in different EDM process.