High-carbon and low-alloy saw blade steel and production method of hot-rolled steel plate thereof

Abstract

The invention relates to high-carbon and low-alloy saw blade steel and a production method of a hot-rolled steel plate thereof. The high-carbon and low-alloy saw blade steel comprises the following chemical components in percentage by weight: 0.78-0.86% of C, 0.15-0.40% of Si, 0.40-0.70% of Mn, P not more than 0.025%, S not more than 0.015%, 0.005-0.050% of Al, 0-0.0050% of Ca, 0.50-0.80% of Cr, 0.15-0.25% of V, Ni not more than 0.25%, Cu not more than 0.20%, and the balance of Fe and inevitable impurities. The production method of the hot-rolled steel plate comprises the steps of blast furnace ironmaking, converter steelmaking, LF furnace refining, slab continuous casting, slab heating, hot continuous rolling, hot-rolled plate coil slow cooling and straightening. The steel produced by the production method has higher hardenability and temper resistant stability, has such characteristics as uniform structure property, excellent plate shape and low residual steel plate stress, and is suitable for producing thick-specification and large-size saw blades.

Description

technical field [0001] The invention relates to the technical field of iron and steel smelting and processing, in particular to a production method of high-carbon low-alloy saw blade steel and its hot-rolled steel plate. Background technique [0002] Saw blades rotate at high speed to cut wood, stone, metal and building structures, etc., and bear large radial and axial stresses. Saw blades are required to have high elastic limit, stiffness, fatigue strength, wear resistance and impact toughness. Therefore, there are strict requirements on the chemical composition, metallurgical quality, and mechanical properties of saw blade steel. For example, saw blade steel is required to have high rigidity and toughness, low heat sensitivity, high red hardness, and hardenability. [0003] At present, the steel types commonly used in the domestic manufacture of saw blades are medium carbon saw blade steel, medium carbon low alloy saw blade steel, high carbon saw blade steel and high carbo...

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Problems solved by technology

[0004] These commonly used saw blade steel grades mentioned above have some problems when they are produced in steel mills or when they are processed and made by saw blade manufacturers: 1. The hardenability is poor, resulting in low hardness of saw blades after heat treatment (such as 45, 30CrMo , 50Mn2V); 2. Insufficient hardenability, resulting in low and uneven hardness of the steel plate after quenching, making it impossible to manufacture thick and large-size saw blades (such as 45, 30CrMo, 65Mn); 3. Slab continuous casting and hot rolling are difficult, The slab defect sensitivity is high, the chemical element segregation is large, and cracks and fractures are easy to occur. After rolling, the strength of the steel plate is high, the residual stress is large, and the shape of the plate is poor. It is not convenient for users to perform mechanical processing, cold processing and heat treatment (such as 50Mn2V, 65Mn, 75Cr1, T8A, T10A); 4. The stability against tempering is poor, and the hardness of the tempered saw blade will decrease rapidly after quenching at a higher temperature (such as 45, 30CrMo, 50Mn2V, 65Mn, 75Cr1 and T8A, T10A )

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