Effect of discharge temperature during annealing at 750 ℃ on microstructure and properties of QT450-10 nodular cast iron

doi:10.13251/j.issn.0254-6051.2022.01.043

Abstract

Abstract: Effect of the discharge temperature on pearlite content, cementite morphology, tensile strength and hardness of the QT450-10 nodular cast iron annealed at 750 ℃ was studied by means of optical microscope and scanning electron microscope. The results show that the microstructure of the nodular cast iron samples are composed of ferrite, globular graphite, graphite particles and a small amount of cementite under different discharge temperatures of the annealing process. Due to the decomposition of pearlite, the residue of cementite and the formation of graphite particles, the tensile strength and Brinell hardness of the samples decrease about 7% and 13% respectively when the discharge temperature is 750 ℃. Due to the decomposition of residual cementite and the growth of graphite particles when the discharge temperature decreases, the tensile strength and hardness decrease. When the discharge temperature is 100 ℃, the tensile strength and Brinell hardness decrease about 10% and 20%, respectively.

Key words: nodular cast iron, annealing, discharge temperature, microstructure, mechanical property

CLC Number:

TG156.25

Gao Yongwang, Kong Xiangling, Li Pengming, Liu Yue. Effect of discharge temperature during annealing at 750 ℃ on microstructure and properties of QT450-10 nodular cast iron[J]. Heat Treatment of Metals, 2022, 47(1): 261-265.

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