The forging process of forging with certain mechanical properties, shape and size is obtained by applying pressure on metal billet with forging machinery to produce plastic deformation. One of the two major components of forging. Through forging can eliminate the metal casting loose, welded holes, forging mechanical properties are generally better than the same material castings. In the machinery of high load, severe working conditions of important parts, in addition to the shape of the simple available rolling plate, profile or welding parts, forging parts.

Forging parts according to the forming method can be divided into: ① open forging (free forging). The use of impact force or pressure to make the metal in the upper and lower two iron (anvil block) deformation to obtain the required forgings, forging than the main manual forging and mechanical forging two. ② Closed mode forging. Metal billets are deformed under pressure in a forging die chamber with a certain shape, which can be divided into die forging, cold heading, rotary forging, extrusion and so on. According to the deformation temperature, forging can be divided into hot forging (the processing temperature is higher than the recrystallization temperature of the billet metal), warm forging (lower than the recrystallization temperature) and cold forging (room temperature).

Forging materials are mainly carbon steel and alloy steel of various components, followed by aluminum, magnesium, titanium, copper and their alloys. Raw materials include bars, ingots, metal powders and liquid metals. The ratio of the cross-sectional area of a metal before deformation to the cross-sectional area after deformation is called the forging ratio. The correct choice of forging ratio to improve product quality and reduce cost is very important.

Railway rail coupler is used to connect rail and sleeper (or other types of rail under the foundation) parts, also known as the middle connection parts. Its function is to fix the rail on the rail pillow, maintain the gauge and prevent the rail from moving in the vertical and horizontal direction with respect to the sleeper. Railway rail coupler system is divided into: shrapnel coupler system, coupler system, spring coupler system.