High-toughness bainite wear-resistant steel suitable for liner plate of large semi-autogenous mill and preparation method of high-toughness bainite wear-resistant steel

Abstract

The invention provides high-toughness bainite wear-resistant steel suitable for a liner plate of a large semi-autogenous mill. The high-toughness bainite wear-resistant steel is prepared from, by masspercent, 0.4% to 0.8% of C, 1.4% to 2.5% of Si, 0.7% to 1.6% of Mn, 1.5% to 2.5% of Cr, 0.2% to 0.7% of Mo, 0.01% to 0.05% of Nb, 0.1% to 0.5% of Cu, 0.1% to 0.5% of Ni, 0 to 0.03% of Al, 0.01% to 0.2% of RE, 0.008% to 0.015% of N, not larger than 0.015% of P, not larger than 0.01% of S, not larger than 0.004% of O and the balance Fe and inevitable impurities. A preparation method is further provided, and comprises the steps that a thick plate formed through smelt forging or rolling is subjected to spheroidizing annealing and heat treatment; and the obtained wear-resistant steel contains nanoscale or submicron-scale carbide-free bainite, thin-film-shaped bainite and a small amount of blocky bainite.

Description

technical field [0001] The invention belongs to the technical field of wear-resistant steel, and in particular relates to a high-strength toughness bainitic wear-resistant steel suitable for lining plates of large semi-autogenous mills and a preparation method thereof. Background technique [0002] In the actual use of semi-autogenous mills, in order to improve work efficiency, the diameter of the cylinder gradually increases, and the diameter of large semi-autogenous mills has exceeded 12m. The liner of the large semi-autogenous mill is subjected to strong repeated impacts of steel balls and mineral materials, grinding and stripping, corrosion of the slurry, and the interaction of wear and corrosion during work, resulting in the continuous migration of the surface material of the liner and accelerating the wear of the liner. Wear and tear, and sometimes even cause the liner to break and fail, especially the damage to the cylinder liner is more serious. According to current...

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Problems solved by technology

Although the hardness reaches HRC60~65 and the toughness reaches 40~80J / cm2 after adopting this technology, it is suitable for use under high stress and low stress wear conditions, but it contains high Al, which increases the difficulty of smelting, and contains a large amount of W increased cost

[0012] The nano-bainite structure obtained in the above patents, in order to shorten the isothermal treatment time, usually requires the addition of expensive alloying elements Co or Al that increases the difficulty of smelting, and the Mn content is high, segregation is prone to occur, and it takes a long time before isothermal quenching The 1100~1200℃ high temperature diffusion annealing, long time high temperature homogenization also increases the cost

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