Heating and rolling production method for improving surface quality of 10Cr17 steel strip

Abstract

The invention discloses a heating and rolling production method for improving the surface quality of a 10Cr17 steel belt, and belongs to the technical field of steel smelting. The 10Cr17 steel strip heating and rolling production method is improved, technological parameters in the 10Cr17 steel strip production process are optimized, the rolling production technology, the surface treatment technology and quality monitoring are improved, the generation of surface defects of the 10Cr17 steel strip is reduced, the surface quality of the produced 10Cr17 steel strip is effectively improved, and technical progress and industrial upgrading of the iron and steel industry are promoted.

Description

Technical Field

[0001] The invention belongs to the technical field of steel smelting, and in particular relates to a heating and rolling production method for improving the surface quality of a 10Cr17 steel strip. Background Art

[0002] In the field of materials science, stainless steel is highly favored for its excellent corrosion resistance, high strength, and good processing properties. Among them, 10Cr17 stainless steel, with its high carbon and chromium content, plays an irreplaceable role in specific application scenarios. However, during the hot rolling production process, defects such as oxide scale, short-line peeling, pad scratches, and banded white spots often appear on the surface of 10Cr17 hot-rolled steel plates. These defects are mainly caused by the following three aspects: First, the hydrogen sulfide gas content in the heating furnace gas is too high. Second, the iron oxide scale formed on the surface of the steel strip is thick and uneven. Third, the heating and rolling process.

[0003] The chemical reaction between hydrogen sulfide and the surface of stainless steel can cause pitting and crevice corrosion, affecting the surface smoothness and cleanliness of the stainless steel. Furthermore, the reaction between hydrogen sulfide and the stainless steel surface can produce black spots, and after pickling, white spots or color defects can appear, affecting the appearance and service life of the stainless steel. The presence of hydrogen sulfide can also increase the surface roughness of the stainless steel, affecting the heating efficiency of the heating furnace and the rolling accuracy of the hot rolling mill, thereby affecting the surface quality after hot rolling.

[0004] At present, the 10Cr17 stainless steel of Taishan Stainless Steel Co., Ltd.'s rolling mill is benchmarked against that of its peers in stainless steel continuous rolling mills. The oxide scale of our hot-rolled black coils is thicker, about 4-6μm thicker than that of continuous rolling production. The oxide scale on both sides and the head and tail of the strip is thicker than that in the middle, which has a greater impact on subsequent pickling. The pickling speed is slow, which affects the improvement of pickling efficiency. Thick and uneven oxide scale will cause white spots or color defects on the surface of the pickled steel strip.

[0005] As an important basic material, the surface quality of 10Cr17 hot-rolled steel plate is directly related to the performance of 10Cr17 stainless steel, affecting the product's aesthetics, corrosion resistance and service life. Therefore, improving the surface quality of 10Cr17 steel strip is an important issue that needs to be urgently addressed in the current steel industry. Summary of the Invention

[0006] In view of the above-mentioned prior art, the purpose of the present invention is to provide a heating and rolling production method for improving the surface quality of 10Cr17 steel strip. The heating and rolling process is a key factor affecting the surface quality of hot-rolled steel plates. By accurately controlling the heating temperature, reducing the amount of reduction, and optimizing the rolling rhythm, the generation of surface defects of 10Cr17 hot-rolled steel plates can be effectively reduced, and the surface quality of 10Cr17 steel strips can be improved.

[0007] To achieve the above object, the present invention adopts the following technical solutions:

[0008] In a first aspect, the present invention provides a heating and rolling production method for improving the surface quality of a 10Cr17 steel strip, the heating and rolling method comprising the following steps:

[0009] (1) During heating, control the hydrogen sulfide gas content in the heating furnace gas to ≤150mg / m3 per standard cubic meter 3 , the heating temperature is controlled in the range of 5-10℃, the gas calorific value is stable at 1600-1700 kcal, and the gas pressure is stable at 8±1KPa;

[0010] (2) During rolling, no rough rolling is performed to remove phosphorus, the oxide scale is retained, and the rolled material does not directly contact the roller surface;

[0011] (3) When producing stainless steel cover unwinding coils, add horizontal spray headers before and after the laminar cooling zone, add cooling water to the horizontal spray headers for horizontal spraying, and set the solenoid valve for automatic start and stop control.

[0012] Preferably, in step (1), the hydrogen sulfide gas content in the heating furnace gas can be controlled by using low-sulfur coal during the heating process and installing a desulfurization device to reduce the hydrogen sulfide gas content.

[0013] Preferably, in step (1), the heating temperature is controlled using a high-precision pyrometer to monitor and accurately control the heating temperature in real time.

[0014] In step (3), the purpose of setting the automatic start and stop control of the solenoid valve is to reduce the cooling water remaining on the surface of the steel strip, ensure the uniform surface temperature of the steel strip, improve the white spot defect of the stainless steel cover during unwinding and peeling, and improve the surface quality of the 10Cr17 steel strip.

[0015] In step (3), the cooling water added to the horizontal spray header is roller cooling water.

[0016] Preferably, the surface quality inspection of the hot rolled steel strip is strengthened to timely discover and treat roller marks and hot rolling scratches, thereby improving the surface quality of the produced 10Cr17 steel strip.

[0017] In a second aspect, the present invention provides an application of the above-mentioned heating and rolling production method in reducing short-line peeling and band-shaped white spot defects on the surface of 10Cr17 steel strip.

[0018] Beneficial effects of the present invention:

[0019] The present invention improves the 10Cr17 steel strip heating and rolling production method, and controls the hydrogen sulfide gas content in the heating furnace gas to ≤150mg / m3 during heating. 3The heating temperature is controlled from the original ±10-±20°C range to a more precise 5-10°C range, stabilizing the gas calorific value and gas pressure. During rolling, rough rolling and dephosphorization are omitted, retaining the oxide scale and preventing direct contact between the rolled material and the roll surface, reducing surface damage. When producing hood-undoing coils, a horizontal spray header is added, replacing the current side spray. A solenoid valve is also installed for automatic on / off control, reducing the amount of cooling water remaining on the strip surface, ensuring a uniform strip surface temperature, and improving the white spot defect that occurs during hood-undoing of stainless steel strips.

[0020] 2. The present invention reduces the occurrence of surface defects of 10Cr17 steel strips by optimizing the process parameters in the production process of 10Cr17 steel strips, improving the rolling production process, surface treatment technology and quality monitoring, effectively improving the surface quality of the produced 10Cr17 steel strips, and promoting technological progress and industrial upgrading in the steel industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 In order to improve the typical appearance of the surface defects of the steel strip before Figure 1 A in the middle is a strip-shaped white spot defect on the surface of the 10Cr17 steel strip. Figure 1 Figure B indicates that there are short-line peeling defects on the surface of the 10Cr17 steel strip.

[0022] Figure 2 To improve the surface quality of the steel strip. DETAILED DESCRIPTION

[0023] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present application belongs.

[0024] The following detailed description is for illustrative purposes only and is intended to provide further explanation of the present invention, rather than to limit the scope of the present invention.

[0025] Example 1: 10Cr17 steel strip production method

[0026] Rolling process: slab heating - descaling - rough rolling - Steckel mill - F3 finishing mill - laminar cooling - coiler - air cooling.

[0027] Pickling process: uncoiler - nine-roller straightening machine - welding - scale breaking - shot blasting - sulfuric acid section - mixed acid section - coiling machine - baling machine - packaging.

[0028] (1) A continuous casting slab with a thickness of 200 mm and a width of 1200-1520 mm was selected. The continuous casting slab was composed of the following components by mass fraction: C: 0.12%, Si: 1.00%, Mn: 1.00%, P: 0.040%, S: 0.030%, Ni: 0.75%, and Cr: 16.00-18.00.

[0029] (2) Heating: Place the continuous casting slab in a heating furnace for heating, and control the hydrogen sulfide content in the heating furnace gas to ≤150mg / m3 per standard cubic meter 3 The gas calorific value is stable at 1600-1700 kcal, the gas pressure is stable at 8±1KPa, the heating time is 210min, and the heating temperature is 1190±5℃;

[0030] (3) Rough rolling: During rolling, rough rolling is not performed to remove phosphorus, the oxide scale is retained, and the rolled material does not directly contact the roller surface;

[0031] (4) Laminar cooling: When producing stainless steel cover unwinding coils, add horizontal spray headers before and after the laminar cooling zone, add cooling water to the horizontal spray headers for horizontal spraying, and set the solenoid valve for automatic start and stop control.

[0032] Example 2: 10Cr17 steel strip quality inspection

[0033] Quality inspection was performed on 10Cr17 steel strips produced using conventional technology and 10Cr17 steel strips produced using improved production technology in Example 1. The number of defects in the produced steel strips (the defects refer to short-line peeling defects and / or banded white spot defects) was counted. The inspection results are shown in Table 1.

[0034] Table 1: 10Cr17 steel strip quality inspection

[0035]

[0036]

[0037] As can be seen from Table 1, the 10Cr17 steel strip produced by the present invention by adjusting the heating process, dephosphorization and cooling means eliminates defects such as banded white spots and short-line peeling, obtains better steel strip surface quality, greatly reduces the pickling cost, and improves the pickling first-class product rate, meeting the requirements of downstream users.

[0038] The above description is merely a preferred embodiment of the present application and is not intended to limit the present application. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent replacements, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A heating and rolling production method for improving the surface quality of 10Cr17 steel strip, characterized in that: The heating and rolling method comprises the following steps: (1) During heating, control the hydrogen sulfide gas content in the heating furnace gas to ≤150mg / m3 per standard cubic meter 3 , the heating temperature is controlled in the range of 5-10℃, the gas calorific value is stable at 1600-1700 kcal, and the gas pressure is stable at 8±1KPa; (2) During rolling, no rough rolling is performed to remove phosphorus, the oxide scale is retained, and the rolled material does not directly contact the roller surface; (3) When producing stainless steel cover unwinding coils, add horizontal spray headers before and after the laminar cooling zone, add cooling water to the horizontal spray headers for horizontal spraying, and set the solenoid valve for automatic start and stop control.

2. The heating and rolling production method according to claim 1, characterized in that In step (1), the hydrogen sulfide gas content in the heating furnace gas can be controlled by using low-sulfur coal during the heating process and installing a desulfurization device to reduce the hydrogen sulfide gas content.

3. The heating and rolling production method according to claim 1, characterized in that In step (1), the heating temperature is controlled by using a high-precision pyrometer to monitor and accurately control the heating temperature in real time.

4. The heating and rolling production method according to claim 1, characterized in that In step (3), the purpose of setting the automatic start and stop control of the solenoid valve is to reduce the cooling water remaining on the surface of the steel strip, ensure the uniform surface temperature of the steel strip, improve the white spot defect of the stainless steel cover during unwinding and peeling, and improve the surface quality of the 10Cr17 steel strip.

5. The heating and rolling production method according to claim 1, characterized in that In step (3), the cooling water added to the horizontal spray header is roller cooling water.

6. Use of the heating and rolling production method according to claim 1 in reducing short-line peeling and band-shaped white spot defects on the surface of 10Cr17 steel strip.

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