A method for producing ultra-low carbon weather-resistant wire rod for protective netting.

Abstract

This invention belongs to the field of steel material processing technology and discloses an ultra-low carbon weather-resistant wire rod for protective netting and its production method. The composition of the wire rod, by weight percentage, is as follows: C≤0.10%, Si≤0.08%, Mn≤0.10%, P≤0.015%, S≤0.008%, Cu 0.20~0.30%, Cr≥1.85%, Mo≥0.45%; the balance is iron and unavoidable impurities. When C<0.03%, Cr+0.8Mo≥2.35%; when 0.03≤C≤0.06%, Cr+0.8Mo≥2.85%; when 0.06%<C≤0.10%, Cr+0.8Mo≥3.20%. The steel wire produced by this invention has suitable strength and excellent corrosion resistance. It does not require hot-dip galvanizing, overcoming the disadvantages of hot-dip galvanized materials, meeting the requirements of coating-free and maintenance-free use, and reducing production and maintenance costs.

Description

Technical Field

[0001] This invention belongs to the field of steel material processing technology, specifically relating to an ultra-low carbon weather-resistant wire rod for protective netting and its production method. Background Technology

[0002] Protective netting is a widely used steel material, extensively applied in key projects such as railways and highways, with annual consumption reaching millions of tons, indicating a huge demand. Because it does not bear stress during use, and to facilitate subsequent processing and manufacturing, the strength requirements for this material are often set with an upper limit, typically ≤430MPa.

[0003] Due to my country's vast territory and diverse natural environment, the service environment of protective netting steel wire varies greatly. Special environments (high temperature, high humidity, high salinity, etc.) place stringent requirements on the weather resistance of the steel wire materials. Currently, this type of material is mainly processed using low-end steel grades such as Q195 and Q235. Through drawing and hot-dip galvanizing, the steel wire material achieves suitable strength and corrosion resistance. Hot-dip galvanizing is used to improve the weather resistance of the steel wire material and extend its service life. The hot-dip galvanizing process is costly, with a processing cost of approximately 800-1200 yuan per ton of steel, and it poses a significant environmental pollution risk. Furthermore, hot-dip galvanized materials require intermediate protective treatments such as painting, further increasing the cost of use.

[0004] In summary, protective netting wire serves various environments, requiring a certain level of weather resistance. Currently, hot-dip galvanizing is used to improve its weather resistance. However, hot-dip galvanizing has the following disadvantages: 1) high cost; 2) significant environmental pollution; 3) pitting corrosion can occur on the surface of hot-dip galvanized materials after impacts. Therefore, exploring wire rods for protective netting that do not require hot-dip galvanizing and can meet the requirements of outdoor coating-free and maintenance-free operation is of great significance. Summary of the Invention

[0005] The purpose of this invention is to address the problems associated with existing hot-dip galvanized wire rods and to provide an ultra-low carbon weather-resistant wire rod for protective netting and its production method. The steel wire produced by this invention has a suitable strength and excellent corrosion resistance. It does not require hot-dip galvanizing during subsequent deep processing, thus overcoming the shortcomings of hot-dip galvanized materials. It meets the requirements for outdoor use without coating and maintenance, and is predicted to have a service life of over 30 years. It significantly reduces production and maintenance costs, resulting in significant economic advantages.

[0006] To achieve the above objectives, the technical solution adopted in this application is as follows:

[0007] The first objective of this invention is to provide an ultra-low carbon weather-resistant wire rod for protective netting, the composition of which, by weight percentage, is as follows: C≤0.10%, Si≤0.08%, Mn≤0.10%, P≤0.015%, S≤0.008%, Cu 0.20-0.30%, Cr≥1.85%, Mo≥0.45%; the balance being iron and unavoidable impurities.

[0008] Preferably, when C < 0.03%, Cr + 0.8Mo ≥ 2.35%; when 0.03 ≤ C ≤ 0.06%, Cr + 0.8Mo ≥ 2.85%; and when 0.06% < C ≤ 0.10%, Cr + 0.8Mo ≥ 3.20%.

[0009] The second objective of this invention is to provide a method for preparing the above-mentioned ultra-low carbon weather-resistant wire rod for protective netting, comprising the following steps:

[0010] S1. Billet heating: Place the billet in a calcining furnace and heat it to 1070-1130℃ to achieve solid solution;

[0011] S2. Rolling and wire drawing: Control the initial rolling temperature to 1020~1080℃, the finishing rolling inlet temperature to 890~930℃, the reduction setting inlet temperature to 890~910℃, and the wire drawing temperature to 870~890℃.

[0012] S3. Wire rod cooling: The inlet roller speed is 0.30m / s. Except for the two sets of insulation covers closest to the winding port, all other insulation covers are closed, or some tail fans are turned on to ensure that the winding temperature is below 550℃. After cooling to room temperature, ultra-low carbon weather-resistant wire rod for protective netting is obtained.

[0013] Preferably, in S1, the cross-section of the billet is 160mm*160mm.

[0014] Preferably, in S1, the heating time is ≥130 min, wherein the time of the heat soaking period is not less than 40 min.

[0015] Preferably, in S1, the temperature difference of the billet cross section is ≤30℃.

[0016] Preferably, in S2, the wire rod diameter is 6.5–8.0 mm.

[0017] Preferably, in S3, the cooling rate of the coil after the tail fan is turned on is 3-5℃ / s.

[0018] Preferably, in S3, the roller speed range is 1.01.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0020] (1) The steel wire produced by this invention has a strength within a suitable range and excellent corrosion resistance. It does not require hot-dip galvanizing during the later deep processing, which can overcome the disadvantages of hot-dip galvanized materials, meet the requirements of outdoor use without coating and maintenance, and is predicted to have a service life of more than 30 years. It significantly reduces production and maintenance costs and has significant economic advantages.

[0021] (2) The wire rod for protective netting produced by this invention has suitable strength (≤430MPa), and the carbon content is controlled to not exceed 0.10%, which facilitates subsequent processing. It can be used directly without intermediate maintenance and has stronger corrosion resistance. Deep processing does not require hot-dip galvanizing treatment. It can be achieved by adjusting the wire rod composition and production process, which reduces processing costs and has environmental advantages. It is easy to operate and has strong feasibility. Attached Figure Description

[0022] Figure 1 This is a metallographic image of the wire rod prepared according to the present invention. Detailed Implementation

[0023] The technical solutions of the present invention will be clearly and completely described below with reference to the data in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0024] It should be noted that the technical terms used in this invention are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of this invention. Unless otherwise specified, all raw materials, reagents, instruments and equipment used in the following embodiments of this invention can be purchased from the market or prepared by existing methods.

[0025] An ultra-low carbon weather-resistant wire rod for protective netting, the composition of which, by weight percentage, is as follows: C≤0.10%, Si≤0.08%, Mn≤0.10%, P≤0.015%, S≤0.008%, Cu 0.20~0.30%, Cr≥1.85%, Mo≥0.45%; the balance being iron and unavoidable impurities; when C<0.03%, Cr+0.8Mo≥2.35%; when 0.03≤C≤0.06%, Cr+0.8Mo≥2.85%; when 0.06%<C≤0.10%, Cr+0.8Mo≥3.20%.

[0026] The ultra-low carbon weather-resistant wire rod used in protective netting has only an upper limit requirement for strength (≤430MPa). Carbon is the element with the most significant solid solution strengthening effect, which leads to a substantial increase in material strength. Therefore, it is crucial to control the carbon content of the material. This patent requires that its carbon content not exceed 0.10%. Copper can improve the corrosion resistance of the material to a certain extent, so the required range is 0.20% to 0.30%. The higher the strength of the material, the worse its weather resistance. Therefore, to ensure the weather resistance of the material, different amounts of corrosion-resistant elements need to be added according to different carbon contents (strengths). However, in order to stably control the carbon content of the material at a low level, the carbon content of scrap steel and raw materials in the smelting process needs to be precisely controlled, which will increase the smelting cost. Therefore, it is necessary to comprehensively consider the carbon content, weather-resistant element content, and smelting cost of the material.

[0027] The preparation method of ultra-low carbon weather-resistant wire rod for protective netting includes the following steps:

[0028] S1. Billet Heating: Place the billet in a calcining furnace and heat it to 1070-1130℃, with a cross-sectional temperature difference of ≤30℃. Maintain a slight positive pressure in the furnace. The 165 square steel billet with a cross-section of 160mm*160mm should be in the furnace for ≥130min, of which the time in the soaking zone should not be less than 40min. Since this material has a high alloy content, it is necessary to ensure the residence time in the soaking zone, because the furnace temperature in the soaking zone is high and uniform, which can ensure that the alloy material is fully dissolved and exert the effect of the alloying elements.

[0029] S2. Rolling and Wire Drawing: The initial rolling temperature is controlled at 1020–1080℃, the finishing rolling inlet temperature at 890–930℃, the reducing inlet temperature at 890–910℃, and the wire drawing temperature at 870–890℃. Wire drawing temperature is a key control indicator for steel rolling and requires precise control. Because this steel contains a certain amount of chromium and molybdenum, which increases the hardenability of the material, the wire drawing temperature must not be too high. Otherwise, during subsequent cooling, excessively high material temperatures can lead to localized rapid cooling, resulting in abnormal structures such as martensite and bainite.

[0030] S3. Wire Rod Cooling: The inlet roller conveyor speed is 0.30 m / s. The entire roller conveyor uses a fixed acceleration range of 1.01, and the overlap point is not fixed to reduce the difference in the same roll. The fans on the Stellmore roller conveyor do not need to be turned on separately to ensure that the microstructure fully completes the ferrite transformation. Except for the two sets of insulation covers closest to the coiling port, all other insulation covers are closed. The front insulation covers are closed to keep the wire rod warm and reduce the cooling rate. The degree of opening of the last two insulation covers depends on the coiling temperature of the wire rod. The coiling temperature is kept below 550℃ to avoid self-tempering of the wire rod due to excessive coiling temperature, which would cause the iron oxide scale on the surface to be too thick and easy to peel off, ultimately affecting the weather resistance of the surface. Under necessary conditions, the tail fans can be turned on appropriately to ensure that the coiling temperature is below 550℃. After cooling to room temperature, ultra-low carbon weather-resistant wire rod for protective netting is obtained.

[0031] The following description, in conjunction with specific embodiments, provides further details.

[0032] Example 1

[0033] An ultra-low carbon weather-resistant wire rod for protective netting has the following composition by weight percentage: C 0.028%, Si 0.063%, Mn 0.031%, P 0.011%, S 0.004%, Cu 0.25%, Cr 1.95%, Mo 0.65%; the balance being iron and unavoidable impurities; when C is 0.028%, C < 0.03%, and Cr + 0.8Mo = 2.47%.

[0034] The preparation method of the ultra-low carbon weather-resistant wire rod for the above-mentioned protective net includes the following steps:

[0035] S1. Heating of billet: Place a 160mm*160mm square billet in a calcining furnace and heat it to 1095℃ with a cross-sectional temperature difference of 20℃. The furnace pressure is kept slightly positive. The 165mm square billet is in the furnace for 155 minutes, of which the time in the soaking zone is not less than 52 minutes.

[0036] S2. Rolling and wire drawing: The starting rolling temperature is controlled at 1053℃, the finishing rolling inlet temperature is 915℃, the reducing inlet temperature is 904℃, the wire drawing temperature is 885℃, and the wire drawing diameter is 6.5mm.

[0037] S3. Wire rod cooling: The inlet roller speed is 0.30m / s, the roller speed range is 1.01, all fans are turned off, the set of heat preservation covers closest to the winding port is opened, and the rest are closed. The winding temperature is 535℃. After cooling to room temperature, ultra-low carbon weather-resistant wire rod for protective netting is obtained.

[0038] Example 2

[0039] An ultra-low carbon weather-resistant wire rod for protective netting has the following composition by weight percentage: C 0.045%, Si 0.024%, Mn 0.026%, P 0.008%, S 0.006%, Cu 0.27%, Cr 2.21%, Mo 0.97%; the balance being iron and unavoidable impurities; when C is 0.045%, then 0.03% < C < 0.06%, and Cr + 0.8Mo = 2.986%.

[0040] The preparation method of the ultra-low carbon weather-resistant wire rod for the above-mentioned protective net includes the following steps:

[0041] S1. Heating of billet: Place a 160mm*160mm square billet in a calcining furnace and heat it to 1115℃ with a cross-sectional temperature difference of 18℃. The furnace pressure is kept slightly positive. The 165 square billet is in the furnace for 148 minutes, of which the time in the soaking zone is not less than 49 minutes.

[0042] S2. Rolling and wire drawing: The starting rolling temperature is controlled at 1067℃, the finishing rolling inlet temperature is 922℃, the reducing inlet temperature is 909℃, the wire drawing temperature is 889℃, and the wire drawing diameter is 8.0mm.

[0043] S3. Wire rod cooling: The inlet roller speed is 0.30m / s, the roller speed range is 1.01, the last fan is turned on at 10%, and the rest are all turned off. After the tail fan is turned on, the cooling rate of the wire rod is 4℃ / s. The two sets of heat preservation covers closest to the winding port are turned on, and the rest are all turned off. The winding temperature is 514℃. After cooling to room temperature, ultra-low carbon weather-resistant wire rod for protective netting is obtained.

[0044] Example 3

[0045] An ultra-low carbon weather-resistant wire rod for protective netting has the following composition by weight percentage: C 0.053%, Si 0.029%, Mn 0.029%, P 0.0013%, S 0.007%, Cu 0.22%, Cr 2.32%, Mo 0.83%; the balance being iron and unavoidable impurities; when C is 0.053%, then 0.03% < C < 0.06%, and Cr + 0.8Mo = 2.984%.

[0046] The preparation method of the ultra-low carbon weather-resistant wire rod for the above-mentioned protective net includes the following steps:

[0047] S1. Heating of billet: Place a 160mm*160mm square billet in a calcining furnace and heat it to 1125℃ with a cross-sectional temperature difference of 15℃. The furnace pressure is kept slightly positive. The 165 square billet is in the furnace for 150 minutes, of which the time in the soaking zone is not less than 51 minutes.

[0048] S2. Rolling and wire drawing: The initial rolling temperature is controlled at 1069℃, the finishing rolling inlet temperature at 921℃, the reduction setting inlet temperature at 896℃, and the wire drawing temperature at 882℃; the wire drawing diameter is 7.0mm.

[0049] S3. Wire rod cooling: The inlet roller speed is 0.30m / s, the roller speed range is 1.01, the fan is completely off, the insulation cover is completely closed, the winding temperature is 529℃, and after cooling to room temperature, ultra-low carbon weather-resistant wire rod for protective netting is obtained.

[0050] Example 4

[0051] An ultra-low carbon weather-resistant wire rod for protective netting has the following composition by weight percentage: C 0.087%, Si 0.042%, Mn 0.033%, P 0.009%, S 0.005%, Cu 0.24%, Cr 2.54%, Mo 1.05%; the balance being iron and unavoidable impurities; when C is 0.087%, then 0.06% < C ≤ 0.1%, and Cr + 0.8Mo = 3.38%.

[0052] The preparation method of the ultra-low carbon weather-resistant wire rod for the above-mentioned protective net includes the following steps:

[0053] S1. Heating of billet: Place a 160mm*160mm square billet in a calcining furnace and heat it to 1090℃ with a cross-sectional temperature difference of 23℃. The furnace pressure is kept slightly positive. The 165 square billet is in the furnace for 146 minutes, of which the time in the soaking zone is not less than 56 minutes.

[0054] S2. Rolling and wire drawing: The starting rolling temperature is controlled at 1069℃, the finishing rolling inlet temperature is 921℃, the reducing inlet temperature is 905℃, the wire drawing temperature is 876℃, and the wire drawing diameter is 6.5mm.

[0055] S3. Wire rod cooling: The inlet roller speed is 0.30m / s, the roller speed range is 1.01, all fans are off, the set of heat preservation covers closest to the winding port is open, and the rest are closed. The winding temperature is 543℃. After cooling to room temperature, ultra-low carbon weather-resistant wire rod for protective netting is obtained.

[0056] Comparative Example 1

[0057] An ultra-low carbon wire rod for protective netting has the following composition by weight percentage: C 0.113%, Si 0.049%, Mn 0.023%, P 0.012%, S 0.006%, Cu 0.25%, Cr 2.35%, Mo 1.63%; the balance being iron and unavoidable impurities; when C is 0.113%, C > 0.1%, and Cr + 0.8Mo = 3.654%.

[0058] The preparation method of the ultra-low carbon weather-resistant wire rod for the above-mentioned protective net includes the following steps:

[0059] S1. Billet Heating: Place a 160mm*160mm square billet in a calcining furnace and heat it to 1100℃, with a cross-sectional temperature difference of 20℃. Maintain a slightly positive furnace pressure. The 165mm square billet should be in the furnace for 149 minutes, of which the time in the soaking zone should not be less than 52 minutes.

[0060] S2. Rolling and wire drawing: The starting rolling temperature is controlled at 1059℃, the finishing rolling inlet temperature is 911℃, the reducing inlet temperature is 902℃, the wire drawing temperature is 886℃, and the wire drawing diameter is 6.5mm.

[0061] S3. Wire rod cooling: The inlet roller speed is 0.30m / s, the roller speed range is 1.01, all fans are off, the set of heat preservation covers closest to the winding port is open, and the rest are closed. The winding temperature is 539℃. After cooling to room temperature, wire rod is obtained.

[0062] Comparative Example 2

[0063] An ultra-low carbon wire rod for protective netting has the following composition by weight percentage: C 0.108%, Si 0.062%, Mn 0.019%, P 0.009%, S 0.007%, Cu 0.21%, Cr 2.54%, Mo 1.27%; the balance being iron and unavoidable impurities; when C is 0.108%, C > 0.1%, and Cr + 0.8Mo = 3.556%.

[0064] The preparation method of the ultra-low carbon weather-resistant wire rod for the above-mentioned protective net includes the following steps:

[0065] S1. Heating of billet: Place a 160mm*160mm square billet in a calcining furnace and heat it to 1094℃ with a cross-sectional temperature difference of 26℃. The furnace pressure is kept slightly positive. The 165 square billet is in the furnace for 143 minutes, of which the time in the soaking zone is not less than 49 minutes.

[0066] S2. Rolling and wire drawing: The initial rolling temperature is controlled at 1061℃, the finishing rolling inlet temperature is 918℃, the reduction setting inlet temperature is 906℃, the wire drawing temperature is 882℃, and the wire drawing diameter is 8.0mm.

[0067] S3. Wire rod cooling: The inlet roller speed is 0.30m / s, the roller speed range is 1.01, all fans are off, the set of heat preservation covers closest to the winding port is open, and the rest are closed. The winding temperature is 545℃. After cooling to room temperature, wire rod is obtained.

[0068] Figure 1 The metallographic structure of the wire rod in Embodiment 1 of the present invention is shown below. Figure 1In the diagram, 'a' represents magnification by 50 times, and 'b' represents magnification by 100 times. For example... Figure 1 As shown, its microstructure is equiaxed ferrite with a grain size of 6.5, lacking pearlite, bainite, martensite, and other abnormal structures.

[0069] The microstructure and properties of the ultra-low carbon weather-resistant wire rods for protective netting prepared in Examples 1-4 and Comparative Examples 1-2 were tested, and the results are shown in Table 1.

[0070] Table 1. Microstructure and properties of ultra-low carbon weather-resistant wire rods used in protective netting in Examples 1-4 and Comparative Examples 1-2

[0071]

[0072]

[0073] As shown in Table 1, the mechanical properties corresponding to Example 1 are as follows: tensile strength Rm = 395 MPa, Rm difference within the same ring = 8 MPa, area reduction Z = 78%, elongation A = 53%, grain size range = 6.5 grade, pearlite ratio = 0, and no abnormal structures such as bainite and martensite; the corrosion resistance of the wire rod is: at 1.0 × 10⁻⁶... -2 A 72-hour cyclic immersion corrosion test was conducted in a mol / L NaHSO3 solution, and the weight loss ratio of the test steel [W(this material) / W(Q235)] = 28.5%; the corrosion rate R after 24 hours of full immersion in a 10% H2SO4 + 3.5% NaCl solution was 0.63 g / (m³). 2 *h), meets the requirements.

[0074] Under the same rolling process conditions, when the carbon content exceeds 0.1%, such as in Comparative Examples 1 and 2, the produced wire rods have no difference in structure and toughness (shrunk area Z and elongation A) compared to the examples, but the strength is higher than the patent requirement range (not greater than 430 MPa), which causes the wire rods to fail to meet the target requirements for weather resistance, weight loss ratio and corrosion rate.

[0075] It should be noted that when numerical ranges are involved in this invention, it should be understood that both endpoints of each numerical range and any value between the two endpoints can be selected. Since the steps and methods used are the same as in the embodiments, preferred embodiments are described here to avoid redundancy. Although preferred embodiments of the invention have been described, those skilled in the art, once they understand the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this invention.

[0076] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A type of ultra-low carbon weather-resistant wire rod for protective netting, characterized in that, The composition of this wire rod by weight percentage is as follows: C≤0.10%, Si≤0.08%, Mn≤0.10%, P≤0.015%, S≤0.008%, Cu 0.20~0.30%, Cr≥1.85%, Mo≥0.45%; the balance is iron and unavoidable impurities. When C < 0.03%, Cr + 0.8Mo ≥ 2.35%; when 0.03 ≤ C ≤ 0.06%, Cr + 0.8Mo ≥ 2.85%; when 0.06% < C ≤ 0.10%, Cr + 0.8Mo ≥ 3.20%. The protective net uses ultra-low carbon weather-resistant wire rods with a tensile strength ≤430MPa; The preparation method of ultra-low carbon weather-resistant wire rod for protective netting includes the following steps: S1. Heating of billet: Place the billet in a calcining furnace and heat it to 1070~1130℃ to solidify it; S2. Rolling and wire drawing: Control the initial rolling temperature to 1020~1080℃, the finishing rolling inlet temperature to 890~930℃, the reduction setting inlet temperature to 890~910℃, and the wire drawing temperature to 870~890℃. S3. Wire rod cooling: The inlet roller speed is 0.30m / s. Except for the two sets of insulation covers closest to the winding port, all other insulation covers are closed, or some tail fans are turned on to ensure that the winding temperature is below 550℃. After cooling to room temperature, ultra-low carbon weather-resistant wire rod for protective netting is obtained.

2. A method for preparing ultra-low carbon weather-resistant wire rod for protective netting as described in claim 1, characterized in that, Includes the following steps: S1. Heating of billet: Place the billet in a calcining furnace and heat it to 1070~1130℃ to solidify it; S2. Rolling and wire drawing: Control the initial rolling temperature to 1020~1080℃, the finishing rolling inlet temperature to 890~930℃, the reduction setting inlet temperature to 890~910℃, and the wire drawing temperature to 870~890℃. S3. Wire rod cooling: The inlet roller speed is 0.30m / s. Except for the two sets of insulation covers closest to the winding port, all other insulation covers are closed, or some tail fans are turned on to ensure that the winding temperature is below 550℃. After cooling to room temperature, ultra-low carbon weather-resistant wire rod for protective netting is obtained.

3. The method for preparing ultra-low carbon weather-resistant wire rod for protective netting according to claim 2, characterized in that, In S1, the cross-section of the billet is 160mm*160mm.

4. The method for preparing ultra-low carbon weather-resistant wire rod for protective netting according to claim 2, characterized in that, In S1, the heating time is ≥130 min, wherein the time of the heat soaking section is not less than 40 min.

5. The method for preparing ultra-low carbon weather-resistant wire rod for protective netting according to claim 2, characterized in that, In S1, the temperature difference across the billet cross section is ≤30℃.

6. The method for preparing ultra-low carbon weather-resistant wire rod for protective netting according to claim 2, characterized in that, In S2, the wire rod diameter is 6.5~8.0mm.

7. The method for preparing ultra-low carbon weather-resistant wire rod for protective netting according to claim 2, characterized in that, In S3, the cooling rate of the coil is 3~5℃ / s after the tail fan is turned on.

8. The method for preparing ultra-low carbon weather-resistant wire rod for protective netting according to claim 2, characterized in that, In S3, the roller speed range is 1.01.

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