The crack problem and cause analysis of the piston rod
Crack causes: The 45 steel forged piston rod with cracks was studied by means of chemical composition, metallographic microscope, scanning electron microscope, energy spectrum analysis, etc. The results show that there are severe decarbonization layers and oxide particles near the crack, and the fracture is dark gray. Therefore, the crack is caused by forging folding. At the same time, observing the metallographic structure that was not quenched and tempered after forging, the grains are coarse and uneven. Therefore, normalizing treatment should be carried out after forging to refine the grains and reduce the cracking tendency of the product during quenching and tempering.
English 
