Effect of tempering temperature on the mechanical properties and micro-structures of 1500 MPa hot stamping steel after quenching
Quenching and tempering treatment were carried out on a 1 500 MPa hot formed steel,and the effects of tempering temperature on the microstructures and mechanical properties were studied us-ing methods such as metallographic microscopy,room temperature tensile testing,and scanning elec-tron microscopy.The results show that if the Cr content is too high,it will reduce the activity of C and inhibit the formation of carbides.Therefore,the main carbides in the steel are M23C6 and M7C3.As the tempering temperature increases to around 400℃,the carbides will transform from M23C6 to M7C3,and the tensile strength,yield strength,and hardness will gradually decrease with the increase of temper-ing temperature.When the tempering temperature exceeds 400℃,the strength will significantly de-crease,the elongation will gradually increase by enhancing tempering temperatures.The strength plastic product will first increase and then decrease with the increase of tempering temperature.The high-dens-ity dislocations in Flat noodles martensite will decrease,and the martensite will engulf and merge with each other,and then gradually blur with the increase of tempering temperature.Ferrites appear in the matrix.In addition,carbides will also precipitate and grow up.
1 500 MPa hot stamping steeltemperingcarbidesmartensitic flat noodles
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