Microstructure and properties of grade E steel after quenching and tempering treatment

doi:10.13251/j.issn.0254-6051.2022.07.030

Abstract

Abstract: Through the optimization of quenching and tempering heat treatment process of grade E steel, the internal reason for the increase of low temperature impact properties was obtained. The microstructure of the steel was studied by optical microscope, and the tensile properties and -40 ℃ impact properties of grade E steel after different heat treatments were studied by tensile testing machine. The results show that uniform sorbite structure is obtained after quenching at 910 ℃ and tempering, and the impact properties is the best. Through the observation of the impact fracture and the study of the precipitation behavior of carbides in steel, the results show that the toughness of the grade E steel quenched and tempered is related to the morphology and distribution of carbides. When tempering temperature is below 550 ℃, carbides mainly precipitate at lath boundary and grain boundary, the impact properties of low temperature is low. When tempering temperature is above 550 ℃, carbides mainly precipitate in the grain and are coarse grained and the ferrite is equiaxed, the impact properties is high.

Key words: E steel, quenching and tempering treatment, couplers, impact properties

CLC Number:

U671.6

Wang Hao, Tian Changliang, Wang An, He Jianchao, Qin Zuoxiang. Microstructure and properties of grade E steel after quenching and tempering treatment[J]. Heat Treatment of Metals, 2022, 47(7): 168-176.

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