Magnesium, calcium and sulfur containing 20MnCr free-cutting gear steel and preparation method thereof

A gear steel, easy-cutting technology, applied in the field of iron and steel metallurgy, can solve the problems of difficult cutting, poor fatigue life of 20MnCr type gear steel, etc.

Inactive Publication Date: 2016-06-15
SHANGHAI UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0009] Aiming at the problems of poor fatigue life and difficult cutting of 20MnCr gear steel produced by existing enterprises,

Method used

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  • Magnesium, calcium and sulfur containing 20MnCr free-cutting gear steel and preparation method thereof
  • Magnesium, calcium and sulfur containing 20MnCr free-cutting gear steel and preparation method thereof
  • Magnesium, calcium and sulfur containing 20MnCr free-cutting gear steel and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0079] Production of new 20MnCr free-cutting gear steel containing magnesium, calcium and sulfur:

[0080] See Table 3 for specific parameters

[0081]

[0082] A. Primary smelting: The primary smelting furnace melts the primary molten steel, and the primary smelting furnace adopts an electric furnace or a converter; control the end point composition, end point carbon 0.12wt.%, end point silicon ≤ 0.07wt.%, end point [S] ≤ 0.020wt. .%, and the desulfurization rate should be ≥ 55%; no slag or less slag is tapped; the temperature of the primary smelting furnace is controlled at 1660°C; steel is tapped within the range of 1630°C, and slag is strictly prohibited during the tapping process; t steel added synthetic slag. When 1 / 3 of the steel is tapped, 2Kg / t steel core aluminum is added for pre-deoxidation along with the steel flow to ensure that the dissolved oxygen content of the molten steel at the refining station is not greater than 70ppm. Alloying in the ladle, Mn and Cr...

Embodiment 2

[0088] Production of new 20MnCr free-cutting gear steel containing magnesium, calcium and sulfur:

[0089] See Table 4 for specific parameters

[0090]

[0091] A. Primary smelting: The primary smelting furnace melts the primary molten steel, and the primary smelting furnace adopts an electric furnace or a converter; control the end point composition, the end point carbon 0.12%, the end point silicon ≤ 0.05%, the end point [S] ≤ 0.015%, and the desulfurization rate It should be ≥65%, and the end point P≤0.015%; no slag or less slag is tapped; the temperature of the primary smelting furnace is controlled at 1660°C; steel is tapped within the range of 1620°C, and slag is strictly prohibited during tapping, and the slag furnace must be removed scum. During the tapping process, synthetic slag is added at 13Kg / t steel. It is strictly forbidden to add Si-based deoxidizers such as Si iron and SiC in the ladle for pre-deoxidation, and to add special pre-melted slag when tapping t...

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Abstract

The invention discloses magnesium, calcium and sulfur containing 20MnCr free-cutting gear steel and a preparation method thereof. The steel is prepared from, by weight percent, 0.15%-0.25% of C, not larger than 0.12% of Si, 0.80%-1.50% of Mn, not larger than 0.035% of P, 0.02%-0.055% of S, 0.80%-1.30% of Cr, 0.015%-0.055% of Al, 0.004%-0.015% of N, 0.0006%-0.004% of Mg, 0.0006%-0.005% of Ca, not larger than 0.0025% of [O] and the balance iron and inevitable impurities. Composite modification is carried out on inclusion by adding a small quantity of calcium and magnesium elements in the refining process, and the composite inclusion with oxide (including multiple oxide) as a core is formed, wherein the core of the composite inclusion is wrapped by sulfide; splitting of the oxide to a steel substrate can be relieved, the anti-fatigue performance can be improved, and the transverse mechanical property of the steel can be improved; and the magnesium, calcium and sulfur containing 20MnCr free-cutting gear steel both good in mechanical performance and cutting performance is produced, and has large economic benefits.

Description

technical field [0001] The invention relates to the technical field of iron and steel metallurgy, in particular to 20MnCr free-cutting gear steel containing magnesium, calcium and sulfur and a preparation method thereof. Background technique [0002] Gears are important transmission components in the automobile and machinery manufacturing industries. During the operation of transmitting power and changing speeds, there are both rolling and sliding between the meshing tooth surfaces, and the roots of the gear teeth are also subject to pulsating and alternating bending stresses. effect. Gear steel is the key material for manufacturing gears, rods and shafts of automobiles and mechanical transmission systems, and its quality requirements are extremely strict. In recent years, good processing performance (including cold, hot workability and machinability) is an important index concerned by the gear industry. [0003] At present, the development of high-performance and economic...

Claims

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Application Information

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IPC IPC(8): C22C38/04C22C38/02C22C38/06C22C38/18C22C38/60C22C33/04C21C7/06C21C7/10
CPCC21C7/0056C21C7/06C21C7/10C22C33/04C22C38/02C22C38/04C22C38/06C22C38/18C22C38/60Y02P10/20
Inventor 付建勋徐杰朱玉员胡德林张明龚涛李健曹中佳李徐吴彦欣
Owner SHANGHAI UNIV
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