A kind of preparation method of bearing steel with low titanium content

A technology for bearing steel and titanium content, applied in the field of bearing steel smelting, can solve the problems of low Ti removal efficiency, affecting converter production efficiency, and low alloy recovery rate.

Active Publication Date: 2020-01-17
DAYE SPECIAL STEEL CO LTD
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  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Since it takes a certain time to melt the iron alloy and complete the oxidation reaction of Ti, this method affects the production efficiency of the converter, and the alloy is added in the converter, the recovery rate of the alloy is low, and the product cost is high
Using slag to adsorb titanium oxide in the refining furnace LF to remove titanium is a method adopted by every bearing steel enterprise. This method has low production cost and simple operation, but the efficiency of Ti removal is too low

Method used

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  • A kind of preparation method of bearing steel with low titanium content
  • A kind of preparation method of bearing steel with low titanium content

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preparation example Construction

[0027] The present invention provides a method for preparing bearing steel with low titanium content, comprising the following steps:

[0028] Step 1, primary smelting: the smelting raw materials are subjected to primary smelting treatment in an electric furnace or a converter, the smelting time is 40-80min, preferably 60min, and the temperature is 1600-1700°C, preferably 1640-1680°C; the whole process of the primary smelting treatment Blowing in argon, the flow rate is 50-150m 3 / h, preferably 100m 3 / h, and stir; when tapping in the primary refining process, add alloys (at least ferrosilicon alloy) to molten steel in the tapping process according to the design composition, and also add carbon powder to the molten steel to adjust it. The C content of the primary smelting steel is obtained, and then the refining slag is added to the primary smelting molten steel.

[0029] After analysis and sampling, the mass percentage of Ti in the above-mentioned primary molten steel is les...

Embodiment 1

[0050] This embodiment is a preparation method of SiMn bearing steel (mainly used for large wind power bearings).

[0051] The design composition of the above-mentioned SiMn type bearing steel is as follows in terms of mass percentage (wt%):

[0052] C Si mn P S Cr Ni Mo Cu Al Ti Ca lower limit 0.90 0.40 0.80 0 0 1.80 0 0.50 0 0 0 0 upper limit 1.05 0.70 1.10 0.025 0.015 2.10 0.25 0.70 0.30 0.050 0.0030 0.0010

[0053] The actual composition of the above-mentioned SiMn type bearing steel is as follows by mass percentage (wt%):

[0054] C Si mn P S Cr Ni Mo Cu Al Ti Ca 0.94 0.57 0.83 0.010 0.002 1.91 0.12 0.53 0.1 0.020 0.0010 0.0003

[0055] The process flow of this embodiment is: electric furnace (hot metal+scrap steel)-refining furnace-VD furnace-casting, and the preparation method includes the following steps:

[0056] (1) Initial smelting: The smelting raw mater...

Embodiment 2

[0076] This embodiment is a preparation method of SiMn bearing steel (mainly used for large wind power bearings).

[0077] The design composition of the above-mentioned SiMn-type bearing steel is the same as that of Example 1, and the actual composition of the above-mentioned SiMn-type bearing steel is as follows in terms of mass percentage (wt%):

[0078] C Si mn P S Cr Ni Mo Cu Al Ti Ca 0.90 0.42 1.04 0.020 0.005 1.85 0.23 0.65 0.2 0.025 0.0018 0.0004

[0079] The preparation method of the present embodiment comprises the following steps:

[0080] (1) Primary smelting: The smelting raw materials (45 tons of molten iron + 35 tons of scrap steel) are subjected to primary smelting treatment in an electric furnace. The smelting time is 80 minutes, the temperature is 1690-1700 ° C, and argon gas is blown into the whole process with a flow rate of 150 m 3 / h, and stir;

[0081] When tapping the steel, add 4.7kg / t of ferrosilicon alloy...

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Abstract

The invention relates to a smelting method of bearing steel, in particular to a preparation method of the bearing steel with the low titanium content. The bearing steel comprises, by mass, no more than 0.0018% of Ti, more than 0.4% of Si (preferably, 0.4-0.6%), and more than 0.9% of C (preferably, 0.90-1.00%). The preparation method comprises the steps of primary smelting, fine smelting, vacuum degassing, pouring and rolling. According to the preparation method, the problem that the titanium content of a bearing steel product is too high is solved under the condition that the smelting cost isnot increased.

Description

technical field [0001] The invention relates to a method for smelting bearing steel, in particular to a method for preparing bearing steel with low titanium content. Background technique [0002] Bearing steel is an important steel material. The nitrides in bearing steel mainly exist in TiN or TiCN. Titanium nitride is a hard and brittle inclusion, which is particularly harmful to the fatigue life of steel. Now users are concerned about metallurgical plants. The internal metallurgical quality of the produced bearing steel, such as inclusions, carbides, etc., is very strict, especially for the size, quantity and distribution of large particles of titanium nitride TiN in the steel. This is because ①Titanium nitride TiN inclusions destroy the steel When the steel is deformed or heat-treated, due to the difference in thermal expansion coefficient between the metal matrix and the TiN inclusions, an initial crack is formed at the interface between the metal and the TiN inclusions,...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C22C33/06C21C7/076C21C7/10C22C38/02
CPCC21C7/076C21C7/10C21C2007/0093C22C33/06C22C38/02Y02P10/20
Inventor 彭先锦潘明旭刘月云
Owner DAYE SPECIAL STEEL CO LTD
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