Cold forging gear steel and preparation method thereof

A gear steel and cold forging technology, applied in the field of steel, can solve problems such as low hardness cold plasticity

Active Publication Date: 2021-12-14
SHOUGANG CORPORATION
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Therefore, traditional gear steel raw materials have been difficult to meet the requirements of cold precision forging technology, and a new type of gear stee

Method used

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  • Cold forging gear steel and preparation method thereof
  • Cold forging gear steel and preparation method thereof
  • Cold forging gear steel and preparation method thereof

Examples

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preparation example Construction

[0045] A preparation method of cold forged gear steel, the method comprising:

[0046] The smelted molten steel is sequentially poured and continuously cast to obtain a slab;

[0047] Heating the cast slab, and finally descaling to obtain the cast slab after descaling;

[0048] Rolling and cooling the cast slab after descaling in sequence to obtain the gear steel;

[0049] The rolling includes rough rolling and finishing rolling, the starting temperature of the rough rolling is 1050-1100°C, the temperature of the finishing rolling is 850-950°C, and the total deformation of the finishing rolling unit is 40% ~60%.

[0050] Through the method of low-temperature and large-deformation finish rolling, the number of deformation bands inside the austenite grains is greatly increased, and a large number of nucleation sites are provided for the ferrite transformation to promote the ferrite transformation. The method of slow cooling after rolling is adopted. , increasing the residence...

Embodiment 1

[0068] In this example, the constituent elements and mass percentages used in the gear steel are: C 0.17%, Si 0.08%, Mn 0.60%, P 0.010%, S 0.025%, Cr 1.30%, Ti 0.04%, Al 0.033%, Cu 0.13%, N0.0065%, the balance is Fe and unavoidable impurities. The metallographic structure of the gear steel includes austenite, and the grain size of the austenite is grade 6-7.

[0069] The production specification is Φ80mm new cold forged gear steel. The specific control parameters are:

[0070] (1) Electric furnace is used for smelting, and the carbon content (mass fraction) at the end of tapping is controlled at 0.10%; then it enters the LF furnace for out-of-furnace refining, and feeds aluminum wire 4.5m / t after the seat cladding, and controls the target aluminum content of J1 to reach 0.060%, Add lime and fluorite according to slag condition and sulfur content during tapping to ensure good slag fluidity; then carry out VD vacuum degassing on the molten steel, the pumping time is 5 minutes, ...

Embodiment 2

[0074] In this embodiment, the constituent elements and mass percentages of the gear steel are: C: 0.15%, Si: 0.05%, Mn: 0.30%, Cr: 0.80%, Ti: 0-0.05%, and the balance is Fe and not Avoid impurities. The metallographic structure of the gear steel includes austenite, and the grain size of the austenite is grade 6-7.

[0075] A kind of cold forging gear steel and preparation method thereof, described method comprises continuous casting, rolling successively, and specific process parameter is as follows:

[0076] pouring the molten steel at a temperature of 1500°C to obtain a slab;

[0077] Heating the billet at a temperature of 1150°C for 2.5 hours, and then descaling;

[0078] The rolling start temperature in the rolling is 1050°C, and the finish rolling temperature in the rolling is 850°C.

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Abstract

The invention belongs to the technical field of steel, and particularly relates to cold forging gear steel and a preparation method thereof. The gear steel is prepared from the following chemical components in percentage by mass: 0.15%-0.25% of C, 0.05%-0.40% of Si, 0.30%-1.40% of Mn, 0-0.03% of P, 0-0.035% of S, 0.80%-1.50% of Cr, 0-0.05% of Ti, 0-0.045% of Al, 0-0.15% of Cu, 0-0.0150% of N and the balance Fe and inevitable impurities. The metallographic structure of the gear steel comprises austenite, and the grain size of the austenite is 6-7 grades. The gear steel meets gear performance, and has low hardness in a hot rolling state, and the problem of large cold deformation resistance of conventional gear steel is solved; through reduction of the contents of Si and Mn elements, and the cold deformation resistance of a gear steel blank is reduced, and meanwhile the problem of local coarse grains is solved.

Description

technical field [0001] The invention belongs to the technical field of iron and steel, in particular to a cold forging gear steel and a preparation method thereof. Background technique [0002] In recent years, with the rapid development of the machining industry, cold forging technology, as a less / no cutting process with less consumables, high efficiency and superior performance, has been widely used in industrial fields such as automobiles, machine tools, and instruments. The huge technical superiority and good economic benefits exhibited by cold forging technology have gradually become the development direction of precision production of small and medium forgings such as gears. [0003] The conventional preparation process of gears is: gear steel raw material → blanking → hot forging → heat treatment after forging → gear processing (hobbing, shaping, milling, planing) → carburizing → quenching, tempering → surface cleaning → inspection → storage. At present, the product...

Claims

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Application Information

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IPC IPC(8): C22C38/28C22C38/20C22C38/06C22C38/04C22C38/02C22C33/04C21C7/06C21D8/00
CPCC22C38/28C22C38/20C22C38/06C22C38/04C22C38/02C22C38/001C22C33/04C21C7/06C21D8/005C21D2211/009C21D2211/005
Inventor 晁月林徐士新程四华孙齐松刘珂王翔丁宁穆相林刘洋洋王晓晨
Owner SHOUGANG CORPORATION
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