TiC-reinforced martensite wear-resistant steel plate with high toughness and good bending performance and manufacturing method thereof

Abstract

The invention relates to a TiC-reinforced martensite wear-resistant steel plate with high toughness and good bending performance and a manufacturing method thereof. The TiC-reinforced martensite wear-resistant steel plate comprises the following elements including 0.18 to 0.30% of C, less than or equal to 0.30% of Si, 0.60 to 1.20% of Mn, 0.20 to 0.40% of Ti, 0.04 to 0.08% of Al, less than or equal to 0.10% of Ni, less than or equal to 0.10% of Cu, 0.20 to 1.00% of Cr, 0.10 to 0.60% of Mo, 0.0010 to 0.0040% of B, 0.001 to 0.005% of Ca, less than or equal to 0.015% of P, less than or equal to 0.003% of S, less than or equal to 0.0015% of O, less than or equal to 0.0030% of N, less than or equal to 0.0002% of H and the balance of Fe, and C-Ti / 4 is more than or equal to 0.13 and less than orequal to 0.25, so that the hardness of a martensite matrix reaches 400-480 HB after TiC is formed; the carbon equivalent CEV is smaller than or equal to 0.65%, and the machining welding performance can meet the manufacturing requirement of high-abrasion-resistance equipment. The technological process comprises the steps of converter or electric furnace steelmaking, LF refining, vacuum degassing, Ca treatment, continuous casting, heating, hot rolling, quenching and low-temperature tempering; the elongation A50 is greater than or equal to 8%; the low-temperature impact toughness Akv at -40 DEG Cis larger than or equal to 20 J, and the cold bending performance d of the steel plate d is equal to 5a and the steel plate does not crack after 90-degree cold bending; and the wear resistance is 1.4times or more than 1.4 times that of low-alloy martensite wear-resistant steel NM450.

Description

technical field [0001] The invention belongs to the field of iron and steel metallurgy, and in particular relates to a TiC reinforced martensitic wear-resistant steel plate with high toughness and good bending performance and a production method thereof. Background technique [0002] Wear-resistant steel plates are widely used in construction machinery, mining and transportation, road transportation and other industries that require high strength and good wear resistance for key components of mechanical equipment, such as excavator buckets, scraper conveyor middle grooves, mining dump trucks bucket and so on. The wear resistance of wear-resistant steel is generally determined by the hardness of the steel plate. At present, the wear-resistant steel on the market is mainly low-alloy martensitic wear-resistant steel, and the hardness is increased by increasing the C content, thereby increasing the wear resistance. However, with the increase of C content and hardness, the cutt...

AI Technical Summary

Problems solved by technology

Hot continuous rolling requires a unique rolling mill and can only produce thin plates, which limits the promotion of this steel type on large-scale construction machinery equipment; at the same time, coiling, flattening, and straightening greatly increase the production process and cost of steel plates

In terms of chemical composition, the C content of this invention is as high as 0.32-0.38%; the Ti content is more than 0.60%; at the same time, 0.02-0.03% Nb is added, and the cost is high; high C and high Ti design will produce a large number of TiC particles, Not good for engineering applications such as welding, cutting, cold bending

In addition, in order to dissolve some coarse TiC particles, the invention adopts a high temperature of 1250-1300°C when rolling steel, which is not good for the production structure and the life of the heating furnace, and will also lead to the coarseness of the original grains, which is not good for the toughness of the steel plate

[0006] In summary, the current production technologies involving TiC particle-reinforced martensitic wear-resistant steel are mainly designed with high C (>0.30%) and high Ti (≥0.40%) content, which requires high superheat continuous casting or high temperature heating Hot continuous rolling process for production; insufficient research on bending properties and low temperature impact toughness of steel plates

In addition, because the Ti element is very active, before TiC is precipitated during the solidification process, it will preferentially react with O and N elements in the molten steel to precipitate a large number of TiO2 or TiN particles, which will not only greatly reduce the low-temperature impact toughness and bending of the steel plate, etc. performance, it will also lead to the consumption of a large amount of Ti and reduce the amount of TiC precipitated, thereby reducing the wear resistance of the steel plate

How to ensure the precipitation of TiC superhard particles and avoid a large amount of precipitation of Ti nitrides or oxides has not been described in the prior art

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