A preparation method of a titanium reinforced hot-dip galvanizing aluminum magnesium S350GD+XM steel suitable for high-cold desert areas

Abstract

This invention belongs to the field of photovoltaic steel technology, specifically disclosing a method for preparing titanium-reinforced hot-dip galvanized aluminum-magnesium S350GD+XM steel suitable for high-altitude desert regions. The S350GD+XM steel uses a specific component ratio, adding titanium to strengthen the matrix. It is produced as a slab through hot-rolling, cold-rolling, continuous annealing, hot-dip galvanizing, cooling, finishing, and straightening processes. Precise control of temperature, reduction, welding parameters, furnace atmosphere, and roller conditions at each stage significantly improves zinc layer adhesion and processability. The product has a yield strength ≥370MPa, tensile strength 420~560MPa, and elongation after fracture ≥16%. It can withstand extreme environments such as strong winds, large temperature differences, and strong ultraviolet radiation, with a corrosion resistance life of up to 30 years, meeting the long-term maintenance-free use requirements of photovoltaic bases in high-altitude desert regions.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic steel technology, specifically to a method for preparing titanium-reinforced hot-dip galvanized aluminum-magnesium S350GD+XM steel suitable for high-altitude and cold desert regions. Background Technology

[0002] Xinjiang, located in Northwest my country, is the core area for the construction of large-scale wind and solar power bases in deserts, Gobi, and arid lands (sand-golands). Its solar power installed capacity and construction speed rank among the top in the country. According to the plan, Xinjiang aims to add 50 million kilowatts of solar power installed capacity by 2025, leading to an explosive growth in demand for structural steel materials such as solar photovoltaic brackets, foundation piles, and module frames.

[0003] The barren desert region of Xinjiang presents an extreme environment characterized by strong winds and sand erosion, large temperature differences between day and night, and strong ultraviolet radiation, which places stringent requirements on the corrosion resistance, mechanical stability, and processing adaptability of photovoltaic structural steel.

[0004] Under strong wind and sand erosion, the coating of current mainstream structural steel wears off quickly, and its anti-corrosion life is far from meeting the 25-year maintenance-free requirement. Ordinary weathering steel relies on a dense protective rust layer to achieve corrosion resistance, but its processing performance such as cold bending, welding, and stamping is poor, and it is prone to cracking, which cannot meet the needs of large-scale forming of photovoltaic components. Conventional zinc-aluminum-magnesium coated steel has insufficient balance between corrosion resistance and cost, and the coating adhesion is weak. During edge bending and cold bending processes, the zinc layer is prone to cracking and peeling, and it cannot pass the bending reliability verification. The risk of anti-corrosion failure at the cut and bending points is prominent. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing titanium-reinforced hot-dip galvanized aluminum-magnesium S350GD+XM steel for photovoltaic applications in high-altitude and cold desert regions, in order to solve the problem that existing photovoltaic steel materials cannot simultaneously meet the requirements of the high-altitude and cold desert environment in Xinjiang and good processability.

[0006] To achieve the above objectives, the basic solution provided by this invention is as follows: a method for preparing titanium-reinforced hot-dip galvanized aluminum-magnesium S350GD+XM steel for photovoltaic applications in cold desert regions, the chemical composition of which includes C: 0.12-0.15%, Si: 0.09-0.15%, Mn: 0.35-0.45%, Ti: 0.035-0.045%, Al: 0.015-0.035%, P≤0.018%, S≤0.008%, N≤70ppm, and residual elements Cr≤0.25%, Ni≤0.15%, Cu≤0.20%, and further includes the following steps: S1. Molten iron undergoes desulfurization, converter smelting, LF furnace refining, and continuous casting processes to form slabs. The [C] content at the time of converter tapping is controlled to be 0.05-0.10%, [P] content ≤0.015%, and [S] content ≤0.035%. S2. The slab is rolled through a hot rolling process, wherein the slab heating temperature, rough rolling temperature, final rolling temperature and coiling temperature are dynamically controlled according to the thickness of the slab. S3. The strip steel after the hot rolling process is sent to the cold rolling process for cold rolling. To improve the adhesion of the zinc coating, the surface roughness Ra is controlled to [specific parameters]. Surface reflectivity ≥60%, and emulsion concentration in the final frame controlled to 0.8%–1.2%; S4. Before the cold-rolled steel strip enters the annealing furnace, the following parameters must be controlled: the surface of the three furnace rolls at the end of the NOF section and the furnace rolls in the PTF section is treated with LOC56 coating; the outlet plate temperature of the NOF section heating section is 620±20℃; the plate temperature of the PTF section soaking section is 700±20℃; the plate temperature difference between the PTF and NOF sections is controlled to 70~85℃; the unit speed is 50~100m / min; the outlet plate temperature of the rapid cooling section is 460±20℃; the heating temperature of the middle section of the furnace nose is set to 450~480℃; and the dew point is controlled to <-30℃. When the strip thickness is <2.5mm, the dew point of the JCF and TDS sections of the annealing furnace is <-20℃, and the oxygen content is <20ppm. When the strip thickness is 2.5~3.0mm, the dew point of the JCF and TDS sections of the annealing furnace is <-25℃, and the oxygen content is <15ppm. After heat treatment, the strip enters the zinc pot, and the zinc liquid temperature is 440±20℃. S5. After zinc plating, the steel strip is cooled. The outlet temperature of the moving cooling fan is <370℃, and the temperature of the steel strip at the top of the No. 1 tower is <240℃. S6. The cooled steel strip is finished and straightened. The finishing mill is controlled by rolling force mode, with a rolling force control range of 100-200t, a finishing elongation of 0.5%-0.9%, and a tension straightening elongation of 0.6%-1.2%.

[0007] The beneficial effects of this invention are as follows: by designing a titanium-reinforced substrate and a Zn-Al-Mg multi-element coating, it achieves the effects of drought resistance, strong ultraviolet radiation resistance and large temperature difference resistance, extending the life of photovoltaic structural components to 30 years. The product has excellent performance, a smooth surface that supports the layout of new energy in extreme areas, adapts to extreme environments, and takes into account wind load resistance, complex bending requirements and total life cycle cost.

[0008] Option 2, which is the preferred option of the basic option, in S1, the target liquidus temperature in the continuous casting process is 1525℃, the average temperature of the molten steel in the ladle of the first casting furnace is 1535~1563℃, the average temperature of the molten steel in the ladle of the continuous casting furnace is 1535~1555℃, and the target temperature of the molten steel in the intermediate ladle is 1545℃.

[0009] Option 3, which is the preferred option of the basic option, in S2, when the thickness of the slab is 1.5 to 3.0 mm, the slab heating temperature is 1220±30℃, the rough rolling temperature is 1090±30℃, the final rolling temperature is 880±20℃, and the coiling temperature is 610±20℃; when the thickness of the slab is 3.01 to 5.0 mm, the slab heating temperature is 1240±30℃, the rough rolling temperature is 1100±30℃, the final rolling temperature is 880±20℃, and the coiling temperature is 580±20℃.

[0010] Option 4, which is the preferred option of the basic option, involves further controlling the performance stability of the cold rolling process by dynamically controlling the total roll reduction based on the finished product thickness in S3. The specific control is as follows: When the finished product thickness is 0.4–0.6 mm: the total reduction is 70%–77%; When the finished product thickness is 0.601–1.199 mm: the total reduction is 60%–75%; When the finished product thickness is 1.200–1.499 mm: the total reduction is 55%–65%; When the finished product thickness is 1.500–1.700 mm: the total reduction is 51%–58%; When the finished product thickness is 1.701–2.0 mm: the total reduction is 50%–57%; When the finished product thickness is 2.001–2.5 mm: the total reduction is 50%–56%; When the finished product thickness is 2.501~3.0mm: the total reduction is 40%~55%.

[0011] Option 5, the preferred option of the basic option, in S3, the rolling mill adopts micro-wave control. When the strip width is below 1200mm, the F1 to F4 rolling mills adopt large bending roll control, and the transverse thickness difference is... The thickness deviation from the target value at 15mm from the edge of the strip is controlled within... .

[0012] Option 6, the preferred option of the basic option, in S4, requires the strip steel to be welded together to ensure the continuity of subsequent processes. Before welding each coil, the welding wheel is inspected and ground. The specific welding parameters for strip steel with a thickness of less than 1.5mm are as follows: When the thickness of the strip is 0.4 to 0.5 mm: welding speed 10.0 ± 1 m / min, welding current 21.5 ± 1 kA, welding pressure 700 ± 50 daN, rolling pressure 1300 ± 50 daN, operating side overlap 3.7 ± 0.2 mm, transmission side overlap 3.4 ± 0.2 mm; When the thickness of the strip is 0.5 to 0.6 mm: welding speed 10.0 ± 1 m / min, welding current 21.7 ± 1 kA, welding pressure 800 ± 50 daN, rolling pressure 1350 ± 50 daN, operating side overlap 3.7 ± 0.2 mm, transmission side overlap 3.4 ± 0.2 mm; When the thickness of the strip is 0.6 to 0.7 mm: welding speed 10.0 ± 1 m / min, welding current 21.9 ± 1 kA, welding pressure 1050 ± 50 daN, rolling pressure 1400 ± 50 daN, operating side overlap 3.7 ± 0.2 mm, transmission side overlap 3.4 ± 0.2 mm; When the thickness of the strip is 0.7~0.8mm: welding speed 10.0±1m / min, welding current 22.4±1KA, welding pressure 1100±50 daN, rolling pressure 1500±50daN, operating side overlap 3.6±0.2 mm, transmission side overlap 3.3±0.2 mm; When the thickness of the strip is 0.8 to 0.9 mm: welding speed 10.0 ± 1 m / min, welding current 23.2 ± 1 kA, welding pressure 1200 ± 50 daN, rolling pressure 1500 ± 50 daN, operating side overlap 3.6 ± 0.2 mm, transmission side overlap 3.3 ± 0.2 mm; When the thickness of the strip is 0.9~1.0mm: welding speed 10.0±1m / min, welding current 24.4±1KA, welding pressure 1350±50 daN, rolling pressure 1500±50daN, operating side overlap 3.5±0.2 mm, transmission side overlap 3.3±0.2 mm; When the thickness of the strip is 1.0~1.1mm: welding speed 10.0±1m / min, welding current 24.8±1KA, welding pressure 1500±100 daN, rolling pressure 1500±50daN, operating side overlap 3.5±0.2 mm, transmission side overlap 3.3±0.2 mm; When the thickness of the strip is 1.1 to 1.2 mm: welding speed 10.0 ± 1 m / min, welding current 25.2 ± 1 kA, welding pressure 1600 ± 100 daN, rolling pressure 1500 ± 50 daN, operating side overlap 3.5 ± 0.2 mm, transmission side overlap 3.2 ± 0.2 mm; When the thickness of the strip is 1.2 to 1.3 mm: welding speed 10.0 ± 1 m / min, welding current 26.0 ± 1 kA, welding pressure 1700 ± 100 daN, rolling pressure 1500 ± 50 daN, operating side overlap 3.5 ± 0.2 mm, transmission side overlap 3.2 ± 0.2 mm; When the thickness of the strip is 1.3 to 1.4 mm: welding speed 10.0 ± 1 m / min, welding current 26.2 ± 1 kA, welding pressure 1700 ± 100 daN, rolling pressure 1500 ± 50 daN, operating side overlap 3.5 ± 0.2 mm, transmission side overlap 3.2 ± 0.2 mm; When the thickness of the strip is 1.4 to 1.5 mm: welding speed 10.0 ± 1 m / min, welding current 26.4 ± 1 kA, welding pressure 1700 ± 100 daN, rolling pressure 1500 ± 50 daN, operating side overlap 3.5 ± 0.2 mm, transmission side overlap 3.2 ± 0.2 mm.

[0013] Option 7 is the preferred option of the basic option. In S4, the hardness of the submerged roller liner in the zinc-aluminum-magnesium process is Shore A67±5. When the strip thickness is above 0.8mm, the diameter of the submerged roller is 760-800mm. When the strip thickness is 0.4-0.8mm, the diameter of the submerged roller is 700-740mm. Detailed Implementation

[0014] The present invention will be further described in detail below through specific embodiments: A method for preparing titanium-reinforced hot-dip galvanized aluminum-magnesium S350GD+XM steel for photovoltaic applications in cold desert regions, comprising the following chemical composition: C: 0.12–0.15%, Si: 0.09–0.15%, Mn: 0.35–0.45%, Ti: 0.035–0.045%, Al: 0.015–0.035%, P≤0.018%, S≤0.008%, N≤70ppm, and residual elements Cr≤0.25%, Ni≤0.15%, Cu≤0.20%, and further comprising the following steps: S1. Molten iron undergoes desulfurization, converter smelting, LF furnace refining, and continuous casting processes to form slabs. The [C] content at the time of converter tapping is controlled to be 0.05-0.10%, [P] content ≤0.015%, and [S] content ≤0.035%. The target liquidus temperature in the continuous casting process is 1525℃, the average temperature of molten steel in the ladle in the first casting furnace is 1535-1563℃, the average temperature of molten steel in the ladle in the continuous casting furnace is 1535-1555℃, and the target temperature of molten steel in the intermediate ladle is 1545℃. S2. The slab undergoes a hot rolling process, during which the slab heating temperature, roughing rolling temperature, final rolling temperature, and coiling temperature are dynamically controlled according to the slab thickness. When the slab thickness is 1.5–3.0 mm, the slab heating temperature is 1220±30℃, the roughing rolling temperature is 1090±30℃, the final rolling temperature is 880±20℃, and the coiling temperature is 610±20℃. When the slab thickness is 3.01–5.0 mm, the slab heating temperature is 1240±30℃, the roughing rolling temperature is 1100±30℃, the final rolling temperature is 880±20℃, and the coiling temperature is 580±20℃. S3. The strip steel after the hot rolling process is sent to the cold rolling process for cold rolling. To improve the adhesion of the zinc coating, the surface roughness Ra is controlled to [specific parameters]. Surface reflectivity ≥60%, emulsion concentration on the last stand controlled to 0.8%–1.2%; the rolling mill adopts micro-wave control, and when the strip width is below 1200mm, the F1–F4 rolling mills adopt large bending roll control, with transverse thickness difference of… The thickness deviation from the target value at 15mm from the edge of the strip is controlled within... ; To further control performance stability in the cold rolling process, the total reduction of the rolls is dynamically controlled based on the finished product thickness, specifically as follows: 0.4–0.6 mm finished product thickness: 70%–77%; 0.601–1.199 mm finished product thickness: 60%–75%; 1.200–1.499 mm finished product thickness: 55%–65%; 1.500–1.700 mm finished product thickness: 51%–58%; 1.701–2.0 mm finished product thickness: 50%–57%; 2.001–2.5 mm finished product thickness: 50%–56%; 2.501–3.0 mm finished product thickness: 40%–55%. Pretreatment control requirements for strip steel entering the annealing furnace: Brush rollers must be replaced promptly when more than 1 / 5 of the brush bristles fall off; the alkaline point of alkali washing and electrolysis must be controlled to 23-27 g / L. When the ratio of total alkaline point to free alkaline point in the degreasing solution in the tank is greater than 2, or when the pH value of the circulating water for hot water washing and rinsing is greater than 9, it is necessary to consider reusing the liquid in sequence or changing the tank for cleaning; the electrolysis current should be 2000±500A (DC); after pretreatment, the surface of the strip steel after hot air drying must not be wet. Wipe the middle and both sides of the upper and lower surfaces of the strip steel with paper towels. When wiping, press your hand on the strip steel for 6-8 seconds. The paper towels should be dry and white or light smoky gray.

[0015] S4. Before the cold-rolled steel strip enters the annealing furnace, the following parameters must be controlled: the surface of the last three furnace rolls of the NOF section and the furnace rolls of the PTF section must be treated with LOC56 coating; the outlet plate temperature of the NOF section heating section must be 620±20℃; the plate temperature of the PTF section soaking section must be 700±20℃; the plate temperature difference between the PTF and NOF sections must be controlled to 70~85℃; the unit speed must be 50~100m / min; the outlet plate temperature of the rapid cooling section must be 460±20℃; the heating temperature of the middle section of the furnace nose must be set to 450~480℃; and the dew point must be controlled to <-30℃. When the strip thickness is <2.5mm, the annealing furnace JC... Section F and TDS have a dew point < -20℃ and an oxygen content < 20ppm. When the strip thickness is 2.5–3.0mm, the dew point of the annealing furnace JCF and TDS sections is < -25℃ and the oxygen content is < 15ppm. After heat treatment, the strip enters the zinc bath at a zinc bath temperature of 440±20℃. To ensure the continuity of subsequent processes, the strips need to be welded together. To further prevent strip breakage, visible defects such as oil and rust on the strip surface must be removed before welding. The welding wheel is inspected and ground before each coil is welded. The specific welding parameters for strips with a thickness of less than 1.5mm are as follows: When the thickness of the strip is 0.4 to 0.5 mm: welding speed 10.0 ± 1 m / min, welding current 21.5 ± 1 kA, welding pressure 700 ± 50 daN, rolling pressure 1300 ± 50 daN, operating side overlap 3.7 ± 0.2 mm, transmission side overlap 3.4 ± 0.2 mm; When the thickness of the strip is 0.5 to 0.6 mm: welding speed 10.0 ± 1 m / min, welding current 21.7 ± 1 kA, welding pressure 800 ± 50 daN, rolling pressure 1350 ± 50 daN, operating side overlap 3.7 ± 0.2 mm, transmission side overlap 3.4 ± 0.2 mm; When the thickness of the strip is 0.6 to 0.7 mm: welding speed 10.0 ± 1 m / min, welding current 21.9 ± 1 kA, welding pressure 1050 ± 50 daN, rolling pressure 1400 ± 50 daN, operating side overlap 3.7 ± 0.2 mm, transmission side overlap 3.4 ± 0.2 mm; When the thickness of the strip is 0.7~0.8mm: welding speed 10.0±1m / min, welding current 22.4±1KA, welding pressure 1100±50 daN, rolling pressure 1500±50daN, operating side overlap 3.6±0.2 mm, transmission side overlap 3.3±0.2 mm; When the thickness of the strip is 0.8 to 0.9 mm: welding speed 10.0 ± 1 m / min, welding current 23.2 ± 1 kA, welding pressure 1200 ± 50 daN, rolling pressure 1500 ± 50 daN, operating side overlap 3.6 ± 0.2 mm, transmission side overlap 3.3 ± 0.2 mm; When the thickness of the strip is 0.9~1.0mm: welding speed 10.0±1m / min, welding current 24.4±1KA, welding pressure 1350±50 daN, rolling pressure 1500±50daN, operating side overlap 3.5±0.2 mm, transmission side overlap 3.3±0.2 mm; When the thickness of the strip is 1.0~1.1mm: welding speed 10.0±1m / min, welding current 24.8±1KA, welding pressure 1500±100 daN, rolling pressure 1500±50daN, operating side overlap 3.5±0.2 mm, transmission side overlap 3.3±0.2 mm; When the thickness of the strip is 1.1 to 1.2 mm: welding speed 10.0 ± 1 m / min, welding current 25.2 ± 1 kA, welding pressure 1600 ± 100 daN, rolling pressure 1500 ± 50 daN, operating side overlap 3.5 ± 0.2 mm, transmission side overlap 3.2 ± 0.2 mm; When the thickness of the strip is 1.2 to 1.3 mm: welding speed 10.0 ± 1 m / min, welding current 26.0 ± 1 kA, welding pressure 1700 ± 100 daN, rolling pressure 1500 ± 50 daN, operating side overlap 3.5 ± 0.2 mm, transmission side overlap 3.2 ± 0.2 mm; When the thickness of the strip is 1.3 to 1.4 mm: welding speed 10.0 ± 1 m / min, welding current 26.2 ± 1 kA, welding pressure 1700 ± 100 daN, rolling pressure 1500 ± 50 daN, operating side overlap 3.5 ± 0.2 mm, transmission side overlap 3.2 ± 0.2 mm; When the thickness of the strip is 1.4 to 1.5 mm: welding speed 10.0 ± 1 m / min, welding current 26.4 ± 1 kA, welding pressure 1700 ± 100 daN, rolling pressure 1500 ± 50 daN, operating side overlap 3.5 ± 0.2 mm, transmission side overlap 3.2 ± 0.2 mm; The hardness of the submerged roll lining in the zinc-aluminum-magnesium process is Shore A67±5. When the strip thickness is above 0.8mm, the diameter of the submerged roll is 760-800mm. When the strip thickness is 0.4-0.8mm, the diameter of the submerged roll is 700-740mm. S5. After zinc plating, the steel strip is cooled. The outlet temperature of the mobile cooling fan should be <370℃, and the temperature at the top of the No. 1 tower turning roller should be <240℃. The steel strip is then passivated. The thickness of the chromium-free passivation film is controlled to 0.6-0.8um. ​​The product baking temperature is 120-140℃. The temperature of the plated steel strip before entering the straightening machine should be <40℃. Otherwise, the water spray pipe in the quenching tank should be opened for water cooling. After water cooling, it must be dried. The hot air temperature should be ≥100℃. S6. The cooled steel strip is finished and straightened. The finishing mill is controlled by rolling force mode, with a rolling force control range of 100-200t, a finishing elongation of 0.5%-0.9%, and a tension straightening elongation of 0.6%-1.2%.

[0016] Performance testing: Tensile test yield strength ≥370MPa, tensile strength 420~560MPa, elongation after fracture ≥16%, pass rate reaches 99.62%, as shown in the following example: The above descriptions are merely embodiments of the present invention, and common knowledge regarding specific structures and characteristics is not elaborated upon here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the structure of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A method for preparing titanium-reinforced hot-dip galvanized aluminum-magnesium S350GD+XM steel for photovoltaic applications in high-altitude desert regions, characterized in that... The chemical composition includes C: 0.12–0.15%, Si: 0.09–0.15%, Mn: 0.35–0.45%, Ti: 0.035–0.045%, Al: 0.015–0.035%, P≤0.018%, S≤0.008%, N≤70ppm, and residual elements Cr≤0.25%, Ni≤0.15%, Cu≤0.20%. It also includes the following steps: S1. Molten iron undergoes desulfurization, converter smelting, LF furnace refining, and continuous casting processes to form slabs. The [C] content at the time of converter tapping is controlled to be 0.05-0.10%, [P] content ≤0.015%, and [S] content ≤0.035%. S2. The slab is rolled through a hot rolling process, wherein the slab heating temperature, rough rolling temperature, final rolling temperature and coiling temperature are dynamically controlled according to the thickness of the slab. S3. The strip steel after the hot rolling process is sent to the cold rolling process for cold rolling. To improve the adhesion of the zinc coating, the surface roughness Ra is controlled to [specific parameters]. Surface reflectivity ≥60%, and emulsion concentration in the final frame controlled to 0.8%–1.2%; S4. Before the cold-rolled steel strip enters the annealing furnace, the following parameters must be controlled: the surface of the three furnace rolls at the end of the NOF section and the furnace rolls in the PTF section is treated with LOC56 coating; the outlet plate temperature of the NOF section heating section is 620±20℃; the plate temperature of the PTF section soaking section is 700±20℃; the plate temperature difference between the PTF and NOF sections is controlled to 70~85℃; the unit speed is 50~100m / min; the outlet plate temperature of the rapid cooling section is 460±20℃; the heating temperature of the middle section of the furnace nose is set to 450~480℃; and the dew point is controlled to <-30℃. When the strip thickness is <2.5mm, the dew point of the JCF and TDS sections of the annealing furnace is <-20℃, and the oxygen content is <20ppm. When the strip thickness is 2.5~3.0mm, the dew point of the JCF and TDS sections of the annealing furnace is <-25℃, and the oxygen content is <15ppm. After heat treatment, the strip enters the zinc pot, and the zinc liquid temperature is 440±20℃. S5. After zinc plating, the steel strip is cooled. The outlet temperature of the moving cooling fan is <370℃, and the temperature of the steel strip at the top of the No. 1 tower is <240℃. S6. The cooled steel strip is finished and straightened. The finishing mill is controlled by rolling force mode, with a rolling force control range of 100-200t, a finishing elongation of 0.5%-0.9%, and a tension straightening elongation of 0.6%-1.2%.

2. The method for preparing titanium-reinforced hot-dip galvanized aluminum-magnesium S350GD+XM steel for photovoltaic applications in high-altitude desert regions, as described in claim 1, is characterized in that... In S1, the target liquidus temperature in the continuous casting process is 1525℃, the average temperature of molten steel in the ladle of the start casting furnace is 1535~1563℃, the average temperature of molten steel in the ladle of the continuous casting furnace is 1535~1555℃, and the target temperature of molten steel in the tundish is 1545℃.

3. The method for preparing titanium-reinforced hot-dip galvanized aluminum-magnesium S350GD+XM steel for photovoltaic applications in high-altitude desert regions, as described in claim 1, is characterized in that... In S2, when the slab thickness is 1.5–3.0 mm, the slab heating temperature is 1220±30℃, the rough rolling temperature is 1090±30℃, the final rolling temperature is 880±20℃, and the coiling temperature is 610±20℃; when the slab thickness is 3.01–5.0 mm, the slab heating temperature is 1240±30℃, the rough rolling temperature is 1100±30℃, the final rolling temperature is 880±20℃, and the coiling temperature is 580±20℃.

4. The method for preparing titanium-reinforced hot-dip galvanized aluminum-magnesium S350GD+XM steel for photovoltaic applications in high-altitude desert regions, as described in claim 1, is characterized in that... In S3, to further control performance stability during the cold rolling process, the total roll reduction is dynamically controlled based on the finished product thickness, as follows: When the finished product thickness is 0.4–0.6 mm: the total reduction is 70%–77%; When the finished product thickness is 0.601–1.199 mm: the total reduction is 60%–75%; When the finished product thickness is 1.200–1.499 mm: the total reduction is 55%–65%; When the finished product thickness is 1.500–1.700 mm: the total reduction is 51%–58%; When the finished product thickness is 1.701–2.0 mm: the total reduction is 50%–57%; When the finished product thickness is 2.001–2.5 mm: the total reduction is 50%–56%; When the finished product thickness is 2.501~3.0mm: the total reduction is 40%~55%.

5. The method for preparing titanium-reinforced hot-dip galvanized aluminum-magnesium S350GD+XM steel for photovoltaic applications in high-altitude desert regions, as described in claim 1, is characterized in that... In S3, the rolling mill uses micro-wave control. When the strip width is below 1200mm, the F1 to F4 rolling mills use large-bend roll control, with a transverse thickness difference of [missing information]. The thickness deviation from the target value at 15mm from the edge of the strip is controlled within... .

6. The method for preparing titanium-reinforced hot-dip galvanized aluminum-magnesium S350GD+XM steel for photovoltaic applications in high-altitude desert regions, as described in claim 1, is characterized in that... In S4, to ensure the continuity of subsequent processes, the strip steel needs to be welded together. Before welding each coil, the welding wheel is inspected and ground. The specific welding parameters for strip steel with a thickness of less than 1.5mm are as follows: When the thickness of the strip is 0.4 to 0.5 mm: welding speed 10.0 ± 1 m / min, welding current 21.5 ± 1 kA, welding pressure 700 ± 50 daN, rolling pressure 1300 ± 50 daN, operating side overlap 3.7 ± 0.2 mm, transmission side overlap 3.4 ± 0.2 mm; When the thickness of the strip is 0.5 to 0.6 mm: welding speed 10.0 ± 1 m / min, welding current 21.7 ± 1 kA, welding pressure 800 ± 50 daN, rolling pressure 1350 ± 50 daN, operating side overlap 3.7 ± 0.2 mm, transmission side overlap 3.4 ± 0.2 mm; When the thickness of the strip is 0.6 to 0.7 mm: welding speed 10.0 ± 1 m / min, welding current 21.9 ± 1 kA, welding pressure 1050 ± 50 daN, rolling pressure 1400 ± 50 daN, operating side overlap 3.7 ± 0.2 mm, transmission side overlap 3.4 ± 0.2 mm; When the thickness of the strip is 0.7~0.8mm: welding speed 10.0±1m / min, welding current 22.4±1KA, welding pressure 1100±50 daN, rolling pressure 1500±50daN, operating side overlap 3.6±0.2 mm, transmission side overlap 3.3±0.2 mm; When the thickness of the strip is 0.8 to 0.9 mm: welding speed 10.0 ± 1 m / min, welding current 23.2 ± 1 kA, welding pressure 1200 ± 50 daN, rolling pressure 1500 ± 50 daN, operating side overlap 3.6 ± 0.2 mm, transmission side overlap 3.3 ± 0.2 mm; When the thickness of the strip is 0.9~1.0mm: welding speed 10.0±1m / min, welding current 24.4±1KA, welding pressure 1350±50 daN, rolling pressure 1500±50daN, operating side overlap 3.5±0.2 mm, transmission side overlap 3.3±0.2 mm; When the thickness of the strip is 1.0~1.1mm: welding speed 10.0±1m / min, welding current 24.8±1KA, welding pressure 1500±100 daN, rolling pressure 1500±50daN, operating side overlap 3.5±0.2 mm, transmission side overlap 3.3±0.2 mm; When the thickness of the strip is 1.1 to 1.2 mm: welding speed 10.0 ± 1 m / min, welding current 25.2 ± 1 kA, welding pressure 1600 ± 100 daN, rolling pressure 1500 ± 50 daN, operating side overlap 3.5 ± 0.2 mm, transmission side overlap 3.2 ± 0.2 mm; When the thickness of the strip is 1.2 to 1.3 mm: welding speed 10.0 ± 1 m / min, welding current 26.0 ± 1 kA, welding pressure 1700 ± 100 daN, rolling pressure 1500 ± 50 daN, operating side overlap 3.5 ± 0.2 mm, transmission side overlap 3.2 ± 0.2 mm; When the thickness of the strip is 1.3 to 1.4 mm: welding speed 10.0 ± 1 m / min, welding current 26.2 ± 1 kA, welding pressure 1700 ± 100 daN, rolling pressure 1500 ± 50 daN, operating side overlap 3.5 ± 0.2 mm, transmission side overlap 3.2 ± 0.2 mm; When the thickness of the strip is 1.4 to 1.5 mm: welding speed 10.0 ± 1 m / min, welding current 26.4 ± 1 kA, welding pressure 1700 ± 100 daN, rolling pressure 1500 ± 50 daN, operating side overlap 3.5 ± 0.2 mm, transmission side overlap 3.2 ± 0.2 mm.

7. The method for preparing titanium-reinforced hot-dip galvanized aluminum-magnesium S350GD+XM steel for photovoltaic applications in high-altitude desert regions, as described in claim 1, is characterized in that... In S4, the hardness of the submerged roll liner in the zinc-aluminum-magnesium process is Shore A67±5. When the strip thickness is above 0.8mm, the diameter of the submerged roll is 760-800mm. When the strip thickness is 0.4-0.8mm, the diameter of the submerged roll is 700-740mm.

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