The forged crankshaft process produces better quality under the same conditions than other machining methods and the crankshafts obtained with the forged crankshaft process have the full fiber nature of the internal metal flow lines and are capable of increasing not less than 20% Fatigue strength. Here we come to a simple understanding of the process route selection.
According to the actual production situation to analyze, the current forging crankshaft used in the typical process can be summarized as follows: blanking - peeling - heating - roll forging billet - flattening - pre-forging - final forging - trimming - twisting - hot finishing - suspension temperature cooling - normalizing + quenching and tempering - straightening - to stress - shot peening - testing - anti-rust treatment, the final inspection storage.
Among them in the unloading stage, the general is the use of refined 45 steel as raw material. Due to the deep decarburization of the domestic raw materials, in order to avoid affecting the surface quality of the forged crankshaft forgings, the material should be peeled off after it is discharged. In the heating sector, the general is the use of step gas heating furnace, the initial forging temperature of 1180 ℃.
In the forging process, the main can be divided into two parts, one is the pre-forging, the other is the final forging. The reason to be pre-cut, mainly to ensure that the metal blank can be evenly distributed, is conducive to the final forging full; In addition, it can significantly reduce the final forging groove load, thereby enhancing the service life of the die. Refining 45 steel forging crankshaft final forging temperature control in 1050 ℃ above. After final forging, the forging is trimmed on a crank press.
Next, the forging crankshaft forgings are also completed turn twist process, calibration process, heat treatment process, cleaning and subsequent processing of other processes. This is because after the heat treatment is completed, the forged crankshaft forgings must first be inspected. Finally check the forging crankshaft forging oil to be qualified to prevent inventory rust.