Study On The Induction Hardening Process Of The Crankshaft Fillet

The crankshaft is one of the most important parts of the engine which main function is to make the piston's back and forth movement into rotating movement and output power.The crankshaft's stress is quite complex while working.The force conditions of main journal,neck connecting rod and crank arm are not identical,they are mainly under repeated bending and torsion load.The main journal and connecting rod journal also withstand strong friction.The main failure forms of crankshaft are fatigue fracture and diameter of axle wear and tear.With the launch of high-power engine,also with long stroke the crankshaft,which increases the size of connecting rod journal and main journal eccentricity,problems caused by technological change is relatively weak link neck down to the point of bending torque is bigger,thus the top priority is to improve the fatigue strength of crankshaft fillet.My company mainly adopts the crankshaft rotating hardening technology on crankshaft surface heat treatment of the main journal,connecting rod journal,flange and thrust surface which has a history of more than 20 years.With the progress of science and technology,more and more people has higher requirement for engine and high-power engine was also constantly updated.More than 90% of the crankshaft's fatigue fractures occur in the connecting rod under the neck to the point with rounded corners and its stress is the largest using Abaqus modeling analysis.Nowadays most famous automobile and engine manufacturers have begun to reinforce the crankshaft fillet which can greatly improve the quality of the service life of the crankshaft and the engine.In this paper,the quenched and tempered steel(45 steel,42CrMo)and non quenched and tempered steel(S38MnSiV)materials of crankshaft has been analyzed by means of raw material inspection,production and processing of crankshaft blank,rounded quenching inductor design,quenching process test plan formulation and adjustment of the crankshaft to the quenching hardness of finished products,quenching layer depthmeasurement and metallographic examination,the single-throw bending fatigue test and finally form a rational scientific technology.The results showed that the crankshaft fillet hardening process is an effective way to improve the crankshaft fatigue strength.