Influences Of Heat Treatment Methods On Properties Of Axle Steel LZ45CrV

As the conventional transport enterprise, rail transport has a directimpact on the development of national economy. Train axle is one of theimportant load-bearing components of railway vehicle during transportprocess, its quality has consanguineous relation with the safety of therailway transport. With the development of velocity and heavy load for lorry,the extensive existing LZ50axle cannot fully meet the requirements ofsafety for lorry. The Ministry of Railways has proposed the development ofnew axle steel LZ45CrV.This paper systematically studied the influence of different normalizingand tempering heat treatment on the microstructure and mechanicalproperties of the new axle steel LZ45CrV. In the dissertation, different heattreatment methods including normalizing+tempering and doublenormalizing+tempering has been designed. Optical microscope, scanningelectron microscope were employed to investigate the phases of LZ45CrVunder different heat treatments. The type, morphology, distribution, structure,composition and impact section proifle of the microstructure were revealed.Impact test, tensile test and other mechanical property test wereimplemented.The normalizing+tempering tests showed that after heat treatment themicrostructure of LZ45CrV was pearlite and ferrite. LZ45CrV obtains thebest matching of strength and toughness after850°C X3.0min/mmnormalizing+500°C tempering.The double normalizing+tempering tests showed that the materialobtained ifner and uniform distribution pearlite and ferrite grains, and hadbetter mechanical properties. The second normalizing played a signiifcantrole on the reifnement and uniform distribution of pearlite. LZ45CrV obtains the best matching of strength and toughness after910°C X2.43min/mm ifrstnormalizing+790。C X1.4min/mm second normalizing+500。C X1.4min/mm tempering. The impact section proifle has small and densedimples. The last normalizing temperature had great effect on the hardnessofLZ45CrV.