Formula and manufacturing method of niobium-added brake disc

Abstract

The formula comprises the following components in percentage by mass: 3.6 to 3.95 percent of C, 1.75 to 1.95 percent of Si, 0.5 to 0.8 percent of Mn, less than or equal to 0.25 percent of Cr, less than or equal to 0.04 percent of Ni, less than or equal to 0.02 percent of Al, less than or equal to 0.4 percent of Cu, 0.15 to 0.3 percent of Nb, less than or equal to 0.12 percent of S, less than or equal to 0.10 percent of P, less than or equal to 0.02 percent of Ti, less than or equal to 0.07 percent of Sn, less than or equal to 0.2 percent of Sb and the balance of Fe. According to the formula of the niobium-added brake disc and the manufacturing method of the niobium-added brake disc, the optimal value of niobium is obtained through multiple tests, meanwhile, FNC treatment is adopted, so that a high-quality product with the pearlite sheet fluctuation value up to 0.52 + / -0.1 mu m and the hardness up to 189.2 + / -2.2 HB is obtained, the quality of the product is unified to a great extent, and meanwhile it is ensured that on the premise that an existing production line is reserved, the production efficiency is greatly improved. And the quality requirement of the current technology is well met, and the development footstep of the automobile technology is followed.

Description

Technical Field

[0001] The invention relates to the technical field of brake disc manufacturing, in particular to a formula of a niobium-added brake disc and a manufacturing method thereof. Background Art

[0002] The brake disc is a braking device for braking and emergency braking of a car. The braking methods of a car can be divided into disc brakes and drum brakes. Disc brakes have better heat dissipation than drum brakes, and are not prone to thermal decay under high-speed braking, so their high-speed braking effect is good. Disc brakes are mainly composed of brake calipers and brake discs. The brake disc is a round disc and is the key to braking. With the development of the automobile industry, the performance requirements for brake discs are getting higher and higher.

[0003] In the prior art, taking Patent 2014104949307 (high-low carbon silicon niobium-containing cast iron brake disc and preparation method thereof) as an example, although there is a process for adding niobium to the brake disc formula, the niobium content is controlled at 0.1-0.3% (of course, it may also be due to the limitation of the process precision at the time). The range is relatively large, which easily leads to uneven product quality and is difficult to adapt to the quality requirements of current technology. With the development of the automotive industry, it is gradually being eliminated. Summary of the invention

[0004] 1. Technical issues to be resolved In view of the shortcomings of the prior art, the present invention provides a formula of a niobium-added brake disc and a preparation method thereof, which solves the problems existing in the prior art.

[0005] (II) Technical solution To achieve the above purpose, the present invention is implemented through the following technical scheme: a formula of a niobium-added brake disc, including C: 3.6-3.95%, Si: 1.75-1.95%, Mn: 0.5-0.8%, Cr: ≤0.25%, Ni: ≤0.04%, Al: ≤0.02%, Cu: ≤0.4%, Nb: 0.15-0.3%, S: ≤0.12%, P: ≤0.10%, Ti: ≤0.02%, Sn: ≤0.07%, Sb: ≤0.2%, and the rest is Fe, and the above-mentioned parts are all mass ratios.

[0006] A method for making a niobium-added brake disc, comprising the above-mentioned formula of the niobium-added brake disc, and the specific operations are as follows: S1. According to the formula of niobium-added brake disc, materials of corresponding mass of C, Mn, Cr, Ni, Al, Cu, Ti, Sn, Sb and Fe and FeNb alloy powder with a particle size of 5 mm are mixed and added into a medium frequency induction furnace for melting; S2, baking the casting treatment ladle, placing the flow inoculant, the inoculant in the mold and the vermicular iron filings at the bottom of the ladle and compacting them; S3, pouring the molten liquid after smelting in the medium frequency induction furnace into the casting treatment bag obtained in step S2 by the flushing method for inoculation and in-mold inoculation; S4, enter the pouring operation and perform FNC treatment to obtain the product.

[0007] Preferably, in step S1, the particle size of the FeNb alloy powder is 5 mm.

[0008] Preferably, in step S1, the temperature of the medium frequency induction furnace is 1450-1500°C.

[0009] Preferably, in step S2, the inoculant is ferrosilicon alloy, and the amount added is determined according to the proportion of Si in the formula of the niobium-added brake disc.

[0010] Preferably, in step S2, the amount of vermicular iron chips added is 0.5-1% of the weight of the smelting liquid.

[0011] Preferably, in step S3, the pouring temperature is 1350-1400°C.

[0012] Preferably, when setting the formula ratio, the following scheme is adopted: C: 3.68%, Si: 1.85%, Mn: 0.6%, Cr: 0.11%, Ni: 0.02%, Al: 0, Cu: 0.14%, Nb: 0.19%, Ti: 0.013%, Sn: 0%, Sb: 0.14%, and the rest is Fe. The above-mentioned numbers are all mass ratios.

[0013] (III) Beneficial effects The present invention provides a formula of a niobium-added brake disc and a method for making the same. It has the following beneficial effects: The formula and production method of the niobium-added brake disc obtained the best niobium value through multiple tests. At the same time, the FNC treatment was used to obtain a high-quality product with a pearlite lamella pacing value of up to 0.52±0.1μm and a hardness of 189.2±2.2HB. This greatly unified the quality of the products and ensured that the existing production line could be retained to meet the quality requirements of the current technology and keep up with the development of automotive technology. This process introduces micron-sized NbB particles in the white bright layer and diffusion layer of FNC to increase wear resistance. It uses the composition of niobium-containing discs and adds 0.15-0.3% Nb through FeNb alloy powder with a particle size of 5 mm. It is suitable for the production of low-carbon and high-carbon discs. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a comparison diagram of the embodiments of the present invention. DETAILED DESCRIPTION

[0015] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0016] See also Figure 1 The present invention provides a technical solution: a formula for a niobium-added brake disc, comprising C: 3.6-3.95%, Si: 1.75-1.95%, Mn: 0.5-0.8%, Cr: ≤0.25%, Ni: ≤0.04%, Al: ≤0.02%, Cu: ≤0.4%, Nb: 0.15-0.3%, S: ≤0.12%, P: ≤0.10%, Ti: ≤0.02%, Sn: ≤0.07%, Sb: ≤0.2%, and the rest is Fe, and the above-mentioned parts are all mass ratios.

[0017] A method for making a niobium-added brake disc, comprising the above-mentioned formula of the niobium-added brake disc, and the specific operations are as follows: S1. According to the formula of niobium-added brake disc, materials of corresponding mass of C, Mn, Cr, Ni, Al, Cu, Ti, Sn, Sb and Fe and FeNb alloy powder with a particle size of 5 mm are mixed and added into a medium frequency induction furnace for smelting. The particle size of the FeNb alloy powder is 5 mm. The temperature of the medium frequency induction furnace is 1450-1500°C. S2, bake the casting treatment ladle, place the flow inoculant, the inoculant in the mold and the vermicular iron chips at the bottom of the ladle and tamp them. The flow inoculant is ferrosilicon alloy, and the amount added is determined according to the proportion of Si in the formula of the niobium-added brake disc. The amount of vermicular iron chips added is 0.5-1% of the weight of the smelting liquid; S3, pouring the smelting liquid after smelting in the medium frequency induction furnace into the casting treatment bag obtained in step S2 by the pouring method for in-stream inoculation and in-mold inoculation, and the pouring temperature is 1350-1400°C; S4, enter the pouring operation and perform FNC treatment to obtain the product.

[0018] It should be noted that when setting the formula ratio, the following scheme is adopted: C: 3.68%, Si: 1.85%, Mn: 0.6%, Cr: 0.11%, Ni: 0.02%, Al: 0, Cu: 0.14%, Nb: 0.19%, Ti: 0.013%, Sn: 0%, Sb: 0.14%, and the rest is Fe. The above numbers are all mass ratios. At this time, the pearlite lamella pacing value (Pearlite lamellarspacing) of the product reaches the highest value within the current Nb range, and the hardness (Hardness) of the product after FNC also reaches the highest value within the previous Nb range.

[0019] Example: The following operations are used to make the brake disc: S1. According to the formula of niobium-added brake disc, materials of corresponding mass of C, Mn, Cr, Ni, Al, Cu, Ti, Sn, Sb and Fe and FeNb alloy powder with a particle size of 5 mm are mixed and added into a medium frequency induction furnace for melting; S2, baking the casting treatment ladle, placing the flow inoculant, the inoculant in the mold and the vermicular iron filings at the bottom of the ladle and compacting them; S3, pouring the molten liquid after smelting in the medium frequency induction furnace into the casting treatment bag obtained in step S2 by the flushing method for inoculation and in-mold inoculation; S4, enter the pouring operation and perform FNC treatment to obtain the product.

[0020] Among them, in terms of formula, four groups of formulas are selected, and the four groups are defined as No.1, No.2, No.3, and No.4. The formulas of the four groups are as follows Figure 1 As shown; The obtained products were tested to determine the pearlite flake spacing and hardness. Figure 1 As shown; According to the test results, when the No. 3 formula is used, the pearlite flake spacing value (Pearlitelamellarspacing) is as high as 0.52±0.1μm, and the hardness reaches 189.2±2.2HB, which is significantly better than other control groups.

[0021] In summary, the formula and production method of the niobium-added brake disc obtained the best value of niobium through multiple tests, and adopted FNC treatment to obtain high-quality products with a pearlite lamella pacing value of up to 0.52±0.1μm and a hardness of 189.2±2.2HB, which greatly unified the quality of the products and ensured that the quality requirements of the current technology could be well adapted to the development of automobile technology under the premise of retaining the existing production line. This process introduces micron-sized NbB particles in the white bright layer and diffusion layer of FNC to increase wear resistance. It uses the composition of niobium-containing discs and adds 0.15-0.3% Nb through FeNb alloy powder with a particle size of 5 mm. It is suitable for the production of low-carbon and high-carbon discs.

[0022] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0023] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A formula for a niobium-added brake disc, characterized in that: Including C: 3.6-3.95%, Si: 1.75-1.95%, Mn: 0.5-0.8%, Cr: ≤0.25%, Ni: ≤0.04%, Al: ≤0.02%, Cu: ≤0.4%, Nb: 0.15-0.3%, S: ≤0.12%, P: ≤0.10%, Ti: ≤0.02%, Sn: ≤0.07%, Sb: ≤0.2%, and the rest is Fe. The above-mentioned numbers are all mass ratios.

2. A method for manufacturing a niobium-added brake disc, characterized in that: The formula of the niobium-added brake disc according to claim 1 is specifically performed as follows: S1. According to the formula of niobium-added brake disc, materials of corresponding mass of C, Mn, Cr, Ni, Al, Cu, Ti, Sn, Sb and Fe and FeNb alloy powder with a particle size of 5 mm are mixed and added into a medium frequency induction furnace for melting; S2, baking the casting treatment ladle, placing the flow inoculant, the inoculant in the mold and the vermicular iron filings at the bottom of the ladle and compacting them; S3, pouring the molten liquid after smelting in the medium frequency induction furnace into the casting treatment bag obtained in step S2 by the flushing method for inoculation and in-mold inoculation; S4, enter the pouring operation and perform FNC treatment to obtain the product.

3. The method for manufacturing a niobium-added brake disc according to claim 2, characterized in that: In step S1 , the particle size of the FeNb alloy powder is 5 mm.

4. The method for manufacturing a niobium-added brake disc according to claim 2, characterized in that: In step S1, the temperature of the medium frequency induction furnace is 1450-1500°C.

5. The method for manufacturing a niobium-added brake disc according to claim 2, characterized in that: In step S2, the inoculant is ferrosilicon alloy, and the amount added is determined according to the proportion of Si in the formula of the niobium-added brake disc.

6. The method for manufacturing a niobium-added brake disc according to claim 2, characterized in that: In step S2, the amount of vermicular iron chips added is 0.5-1% of the weight of the smelting liquid.

7. The method for manufacturing a niobium-added brake disc according to claim 2, characterized in that: In step S3, the pouring temperature is 1350-1400°C.

8. The method for manufacturing a niobium-added brake disc according to claim 2, characterized in that: When setting the formula ratio, the following scheme is adopted: C: 3.68%, Si: 1.85%, Mn: 0.6%, Cr: 0.11%, Ni: 0.02%, Al: 0, Cu: 0.14%, Nb: 0.19%, Ti: 0.013%, Sn: 0%, Sb: 0.14%, and the rest is Fe. The above-mentioned numbers are all mass ratios.

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