A study of machining characteristics of AISI 4340 alloy steel by wire electrical discharge machining process

Abstract However, over the past fifty years the rapid growth in the development of harder, tougher and stronger work piece materials. The 4340 steel is a medium carbon, low alloy steel (Heat-treatable). It has excellent toughness, superior strength in the heat treated condition, good fatigue resistance, admirable hardness and wear resistance. The 4340 steel is widely used in different applications as: Automotive system, Aircraft landing gears, transmission, Gas & oil sectors, forged hydraulic and structural areas. A WEDM is a non-contact erosion cutting process. It has a capability of machining parts with varying hardness, intricate shapes, contours and complex shapes. The WEDM is a competitive and economical machining option fulfilling the demanding machining requirements. In WEDM the electric sparks is generated between the tool and workpiece and it used to cut the various types of electrical conductive as well as non-conductive materials. The machining process is controlled by various process parameters such as pulse on time, pulse off time and servo voltage. It was found that servo-voltage and pulse on time are the significant factors affecting the SR. While increases the pulse off time and pulse duration affects the MRR, as the reason of pulse off time limits the spark energy and interrupting the discharge energies. From the experimental result, increases the pulse duration, wire speed, open circuit voltage causes the increases in material removal rate. The wire speed and wire tension play the dominant role in the machining of 4340 steel. Machining with zinc coated brass is found to be the best alternative to the 4340 alloy steel.