Yang Yu,Wang Tianxiao,Song Xiaoming,et al.Effect of Nioblum on Microstructure and Properties of 65Mn High Carbon Cutting Tool Steel[J].Special Steel,2026,47(01):28-33.
Yang Yu,Wang Tianxiao,Song Xiaoming,et al.Effect of Nioblum on Microstructure and Properties of 65Mn High Carbon Cutting Tool Steel[J].Special Steel,2026,47(01):28-33. DOI: 10.20057/j.1003-8620.2025-00067.
Effect of Nioblum on Microstructure and Properties of 65Mn High Carbon Cutting Tool Steel
In order to solve the problem of poor toughness and brittle fracture of 65Mn high carbon cutting tool steel, tensile and impact tests, optical microscope, scanning electron microscope and other technical means were used to compare and analyze the influence of
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[Nb]0.03% addition on the microstructure and properties of 65Mn cutting tool steel during hot rolling and heat treatment.The results showed that the diameter of pearlite clusters in 65MnNb hot-rolled plates was 21 μm smaller than that in 65Mn hot-rolled plates, and the interlayer spacing of pearlite was 0.14 μm smaller. When 250 ℃-500 ℃tempering was carried out after 820 ℃ quenching, with the increased of tempering temperature, the strength and hardness of two kinds of component tool steel samples gradually decreased, and the elongation and impact toughness gradually increased; Under the same heat treatment process conditions, the strength and impact absorption of 65MnNb cutting tool steels were higher, while there was no obvious difference in hardness and elongation.The optimum heat treatment temperature of 65MnNb cutting tool steel was about 350 ℃ to 400 ℃, and the structure was tempered sorbite. The yield strength was 1 753 MPa, the tensile strength was 1 820 MPa, the hardness was 52.3HRC, and the impact energy was 22.1 J. However the optimum tempering temperature 65Mn steel sample was about 450 ℃, the yield strength was 1 067 MPa, the tensile strength was 1 263 MPa, the hardness was 46.6HRC, and the impact energy was 18.7 J. Its tempering and embrittlement temperature was about 400 ℃.