Secondary hardening behavior of 2000 MPa level low cost compound strengthened ultra-high strength steel

doi:10.13251/j.issn.0254-6051.2020.11.002

Abstract

Abstract: Secondary hardening behavior of 2000 MPa level low cost compound strengthened ultra-high strength AIR0509 steel was studied by means of SEM and HRTEM, and compared with the AerMet100 steel widely used in the aviation field. The results show that the experimental steel exhibits an obvious secondary hardening phenomenon, the best combination of strength and toughness is obtained when tempered at 535 ℃ for 4 h, and the tensile strength, yield strength and impact absorbed energy are 2020 MPa, 1780 MPa and 68 J, respectively, the yield strength increases by 480 MPa compared to the quenched steel, which is dominated by the co-precipitation of both M₂C carbide and β-NiAl intermetallic. Moreover, the AIR0509 steel shows strong resistance to overaging compared to AerMet100 steel.

Key words: ultra-high strength steel, compound strengthening, secondary hardening, M₂C, β-NiAl

CLC Number:

TG142.1

Wang Chunxu, Zhang Pengjie, Gao Yuanhang, Li Yong, Han Shun, Liu Shaozun. Secondary hardening behavior of 2000 MPa level low cost compound strengthened ultra-high strength steel[J]. Heat Treatment of Metals, 2020, 45(11): 7-10.

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