Production method of Mn-Cr high-performance gear steel

A gear steel, high-performance technology, applied in the field of alloy steel, can solve the problems of unstable carburized structure of gears, affect the precision and service life of gears, achieve optimal shape and distribution, solve the contradiction of deoxidation and sulfur retention, and optimize the refining process Effect

Active Publication Date: 2016-08-10
ZENITH STEEL GROUP CORP +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] Whether the end hardenability is stable or not has a great influence on the deformation of the gear after heat treatment, and the deformation of the gear directly affects the noise of the gearbox; fine and uniform austenite grains can stabilize the end harden On the other hand, after carburizing the gear steel, the fatigue cracks start at the inclusions and expand along the grain boundaries in the carburized layer, so the grain refinement can also be Significantly improve the fatigue performance; however, the appearance of the banded structure in steel often easily causes the instability of the carburized structure of the gear, making the deformation of the carburized layer irregular, resulting in the deformation of the gear workpiece and the reduction of fatigue performance, affecting the accuracy and service life of the gear ; In addition, good cutting performance is an important condition to ensure gear machining accuracy and reduce machining costs

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0021] The process route of EAF-CONVERTER electric converter smelting→LF furnace refining→VD vacuum treatment→CCM continuous casting is used to produce Mn-Cr series high-performance gear steel.

[0022] Smelting product composition control: C: 0.17~0.22%, Si: 0.15~0.25%, Mn: 1.10~1.40%, Cr: 1.00~1.30%, Mo≤0.08%, B≤0.0005%, Cu≤0.02%, Ni≤ 0.02%, Al: 0.025-0.055%, P: ≤0.015%, S: 0.020-0.035%, N: ≤130ppm.

[0023] The total charge of the electric converter is controlled at 102.2 tons, the molten iron ratio is 90%, the pig iron addition is 3.6 tons, and the rest is high-quality steel scrap. Tapping end point composition C: 0.10%, P: 0.008%, tapping temperature T: 1645°C, tapping volume 86.3 tons; adding 100kg of Al blocks and 50kg of calcium carbide for deoxidation during tapping, adding 780kg of low-carbon ferromanganese and 220kg of low-titanium Ferrosilicon, 1550kg of low-carbon and low-titanium ferrochrome and 375kg of high-carbon ferromanganese are alloyed after the furnace, ...

Embodiment 2

[0029] The process route of EAF-CONVERTER electric converter smelting→LF furnace refining→VD vacuum treatment→CCM continuous casting is used to produce Mn-Cr series high-performance gear steel.

[0030] Smelting product composition control: C: 0.17~0.22%, Si: 0.15~0.25%, Mn: 1.10~1.40%, Cr: 1.00~1.30%, Mo≤0.08%, B≤0.0005%, Cu≤0.02%, Ni≤ 0.02%, Al: 0.025-0.055%, P: ≤0.015%, S: 0.020-0.035%, N: ≤130ppm.

[0031] The total charge of the electric converter is controlled at 103.4 tons, the molten iron ratio is 91%, the pig iron addition is 3.1 tons, and the rest is high-quality steel scrap. Tapping end point composition C: 0.12%, P: 0.0010%, tapping temperature T: 1641°C, tapping volume 86.8 tons; adding 100kg of Al blocks and 50kg of calcium carbide for deoxidation during tapping, adding 800kg of low-carbon ferromanganese and 210kg of low-titanium Ferrosilicon, 1750kg of low-carbon and low-titanium ferrochrome and 350kg of high-carbon ferromanganese are alloyed after the furnace,...

Embodiment 3

[0037] The process route of EAF-CONVERTER electric converter smelting→LF furnace refining→VD vacuum treatment→CCM continuous casting is used to produce Mn-Cr series high-performance gear steel.

[0038] Smelting product composition control: C: 0.17~0.22%, Si: 0.15~0.25%, Mn: 1.10~1.40%, Cr: 1.00~1.30%, Mo≤0.08%, B≤0.0005%, Cu≤0.02%, Ni≤ 0.02%, Al: 0.025-0.055%, P: ≤0.015%, S: 0.020-0.035%, N: ≤130ppm.

[0039] The total charge of the electric converter is controlled at 105.9 tons, the ratio of hot metal to 88%, the amount of pig iron added is 5.6 tons, and the rest is high-quality steel scrap. Tapping end point composition C: 0.08%, P: 0.006%, tapping temperature T: 1650°C, tapping amount 85.6 tons; adding 120kg of Al blocks and 50kg of calcium carbide for deoxidation, adding 700kg of low-carbon ferromanganese and 250kg of low-titanium Ferrosilicon, 1800kg of low-carbon and low-titanium ferrochrome and 500kg of high-carbon ferromanganese are alloyed after the furnace, and 750...

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Abstract

The invention belongs to the technical field of alloy steel, and in particular, relates to a manufacturing method of Mn-Cr gear steel. The gear steel comprises the following components: 0.17-0.22% of C, 0.15-0.25% of Si, 1.10-1.40% of Mn, 1.00-1.30% of Cr, Mo not more than 0.08%, B not more than 0.0005%, Cu not more than 0.02%, Ni not more than 0.02%, 0.025-0.055% of Al, P not more than 0.015%, 0.020-0.035% of S, N not more than 130 ppm, and the balance of iron. The method improves the cleanness of molten steel through optimizing the refining process and the slag system control, performs the nitrogen adding treatment through a wire feeding procedure to effectively refine grains of the aluminum deoxidation gear steel, realizes precise control of hardenability alloy elements, solves the deoxidation and sulfur maintaining contradiction, and guarantees excellent pouring performance of the molten steel and excellent cutting performance of the gear steel.

Description

technical field [0001] The invention belongs to the technical field of alloy steel, and in particular relates to a manufacturing method of Mn-Cr series gear steel. Background technique [0002] Based on the actual working environment and requirements of its finished parts, gear steel usually needs to have good strength, toughness and wear resistance. In addition, high-performance gear steel also needs to withstand impact, bending and contact stress well, and can It meets the requirements of small deformation, high precision and low noise. [0003] Due to the special purpose of gear steel, the various stresses that gears must bear during work are important reasons for their fatigue failure. The main source of fatigue cracks in gear steel is oxide inclusions, and the total amount of inclusions is mainly determined by the oxygen content in the steel. [0004] Whether the end hardenability is stable or not has a great influence on the deformation of the gear after heat treatme...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C22C38/18C22C38/04C22C38/02C22C38/12C22C38/16C22C38/08C22C38/06C22C33/06C21C7/06C21C7/10
CPCC21C7/0006C21C7/06C21C7/10C22C33/06C22C38/02C22C38/04C22C38/06C22C38/08C22C38/12C22C38/16C22C38/18C22C38/32
Inventor 朱富强高宇波徐必靖王二庆冷永磊万文华
Owner ZENITH STEEL GROUP CORP
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