A TIC-enhanced martensitic wear-resistant steel plate with high toughness and good bending performance and its manufacturing method

Abstract

The invention relates to a TiC enhanced martensitic wear-resistant steel plate with high toughness and good bending performance and a manufacturing method thereof. Element content: C: 0.18-0.30%, Si: ≤0.30%, Mn: 0.60-1.20%, Ti :0.20~0.40%, Al: 0.04~0.08%, Ni: ≤0.10%, Cu: ≤0.10%, Cr: 0.20~1.00%, Mo: 0.10~0.60%, B: 0.0010~0.0040%, Ca: 0.001~ 0.005%, P: ≤0.015%, S: ≤0.003%, O: ≤0.0015%, N: ≤0.0030%, H: ≤0.0002%, the balance is Fe; and satisfy 0.13≤C‑Ti / 4≤0.25, The hardness of the martensite matrix after forming TiC thus reaches 400-480HB; the carbon equivalent CEV: ≤0.65%, and the machining and welding performance can meet the manufacturing requirements of high wear resistance equipment. The process flow is: converter or electric furnace steelmaking->LF refining->vacuum degassing->Ca treatment->continuous casting->heating->hot rolling->quenching->low temperature tempering. Elongation A 50 ≥8%; low temperature impact toughness: ‑40°C Akv≥20J, cold bending performance of steel plate: d=5a cold bending at 90° without cracking. The wear resistance reaches 1.4 times or more than that of low alloy martensitic 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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