Preparation method of rare earth-containing guide and guard material for production of section steel

Abstract

This invention discloses a method for preparing rare-earth-containing guide materials for producing steel profiles. The chemical composition of the rare-earth-containing guide material, by weight percentage, is as follows: C 0.80–2.30%; Si 0.10–0.65%; Mn 0.85–2.50%; P ≤0.020%; S ≤0.025%; V ≤0.03%; Cr 0.65–1.35%; Mo 0.06–0.77%; RE content ≥0.0020%; and the remainder being Fe and unavoidable impurities. The preparation method includes steelmaking processes and ingot rolling processes. The purpose of this invention is to provide a method for preparing rare-earth-containing guide materials for producing steel profiles, and to smelt and prepare guide materials with good strength and toughness ratios and excellent wear resistance.

Description

Technical Field

[0001] This invention relates to the field of metallurgical materials technology, and in particular to a method for preparing rare earth-containing guide materials for producing steel profiles. Background Technology

[0002] During the rolling process of structural steel, guides are required on the rolling mill to prevent the rails from twisting, which places higher demands on the quality and preparation of the guides. Whether using BD roll systems or universal roll systems, the main function of the guides is to guide and support the rails during rolling, reducing rail bends and buckles, and preventing direct impacts between the rails and rolls, roller conveyors, or other equipment. The guides maintain contact with the rails (especially at both ends) during rolling, thus significantly impacting the surface quality of the rails.

[0003] Guide plates slide directly in contact with high-temperature, high-speed rolled workpieces during operation. Although forced cooling with water is provided, field tests show that the temperature of the guide plate's working surface can reach 300℃. This necessitates that the guide plate possess high wear resistance and resistance to thermal fatigue. Under these conditions, even though the guide plate is typically made of chilled cast iron with high hardness and good wear resistance, its wear and damage are still very severe. Given the special working conditions of guide plate materials, innovation and improvement of guide plate materials are crucial. Therefore, designing new wear-resistant guide materials is of great significance. Summary of the Invention

[0004] The purpose of this invention is to provide a method for preparing rare earth-containing guide materials for producing steel profiles, thereby smelting and preparing wear-resistant guide materials with excellent mechanical properties.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] This invention discloses a method for preparing rare earth-containing guide materials for producing steel profiles. The chemical composition of the rare earth-containing guide material, by weight percentage, is as follows: C 0.80–2.30%; Si 0.10–0.65%; Mn 0.85–2.50%; P ≤0.020%; S ≤0.025%; V ≤0.03%; Cr 0.65–1.35%; Mo 0.06–0.77%; RE content is above 0.0020%; and the remainder is Fe and unavoidable impurities.

[0007] The steelmaking process is as follows: high-quality scrap steel → electromagnetic induction smelting in a 25kg vacuum furnace → alloy addition → demolding into ingots; the smelting adopts aluminum-free deoxidation alloying, the vacuum degree throughout the process is ≤0.10KPa, the deep vacuum time is ≥30min, and the total smelting time is ≥45min.

[0008] The main ingot rolling process is as follows: ingot casting → heating → two-roll rolling → cooling → sawing → reheating → laboratory heat treatment → cooling; the ingot heating temperature is 1250℃-1400℃; the heating power is 10℃ / min, and the holding time is 40min-100min; the forging temperature is ≥1150℃, and the final forging temperature is 720~760℃; after forging, it is sawn into 230mm×150mm×22mm size, reheated to 930℃, held for 30min and then cooled naturally.

[0009] Furthermore, the chemical composition of the rare earth-containing guide material by mass percentage is as follows: C 1.85%; Si 0.25%; Mn 1.45%; P 0.012%; S 0.007%; V 0.030%; Cr 1.22%; Mo 0.35%; RE 0.0050%; with the remainder being Fe and unavoidable impurities.

[0010] Furthermore, the chemical composition of the rare earth-containing guide material by mass percentage is as follows: C 2.14%; Si 0.20%; Mn 1.30%; P 0.013%; S 0.004%; V 0.030%; Cr 0.87%; Mo 0.48%; RE 0.0060%; with the remainder being Fe and unavoidable impurities.

[0011] Furthermore, the chemical composition of the rare earth-containing guide material by mass percentage is as follows: C 2.07%; Si 0.22%; Mn 1.41%; P 0.013%; S 0.003%; V 0.029%; Cr 0.95%; Mo 0.32%; RE 0.0070%; with the remainder being Fe and unavoidable impurities.

[0012] Furthermore, the rare earth-containing guide material prepared by the aforementioned method for preparing rare earth-containing guide materials for production steel exhibits improved strength and toughness.

[0013] Compared with the prior art, the beneficial technical effects of the present invention are as follows:

[0014] This invention designs a new guided satellite material, optimizes its chemical composition and preparation process, and improves the strength and toughness of the material by adjusting the main elemental composition of the material. Detailed Implementation

[0015] The chemical composition of each embodiment for preparing the new guide material is shown in Table 1.

[0016] Table 1. Components of each embodiment (mass percentage / %)

[0017]

[0018] Table 2 Process of each embodiment

[0019]

[0020]

[0021] Sample properties: Mechanical properties were tested by compression test. 0.5 mm was ground off the top surface of the sample plate, 5 test points were set, and Rockwell hardness was tested. The average value was calculated. The test temperature was 20℃ ± 5℃. The experimental results are shown in Table 3.

[0022] Table 3 Mechanical properties of each embodiment

[0023]

[0024] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for preparing rare earth-containing guide materials for producing steel profiles, characterized in that, The chemical composition of the rare earth-containing guide material by mass percentage is: C 1.85%; Si 0.25%; Mn 1.45%; P 0.012%; S 0.007%; V 0.030%; Cr 1.22%; Mo 0.35%; RE 0.0050%; the remainder being Fe and unavoidable impurities; wherein: The steelmaking process is as follows: high-quality scrap steel → electromagnetic induction smelting in a 25kg vacuum furnace → alloy addition → demolding into ingots; the smelting adopts aluminum-free deoxidation alloying, the vacuum degree is 0.09KPa throughout the process, the deep vacuum time is 30min, and the total smelting time is 48min. The main ingot rolling process is as follows: ingot casting → heating → two-roll rolling → cooling → sawing → reheating → laboratory heat treatment → cooling; the ingot heating temperature is up to 1260℃; the heating power is 10℃ / min, and the holding time is 80min; the initial rolling temperature is 1230℃, and the final rolling temperature is 730℃; after rolling, it is sawed into 230mm×150mm×22mm size, reheated to 930℃, held for 30min and then cooled naturally. Its yield strength is 282 MPa, its tensile strength is 435 MPa, and its average Rockwell hardness is 64.3 HRC.

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