A production method of a thin-gauge weathering-resistant steel for a photovoltaic support

Abstract

The application discloses a production method of a thin-gauge weather-resistant steel for a photovoltaic support, which comprises a smelting-continuous casting production process and a hot rolling production process; the casting billet discharge temperature is 1240±20 DEG C, the final rolling temperature of the finishing rolling is 890±10 DEG C, the cold speed is 10-20 DEG C / S, and the thickness of the hot rolled steel strip is 1.8-2.5 mm; laminar cooling is adopted, and the coiling temperature is 650±10 DEG C; the mass percentage of the chemical components of the weather-resistant steel is as follows: C: 0.06-0.08%, Si: 0.15-0.25%, Mn: 0.35-0.45%, P: 0.03-0.04%, S: ≤0.001%, Cu: 0.26-0.30%, Cr: 0.55-0.65%, Ti: 0.020-0.030%, and the rest is iron and impurities. The application adopts a conventional CSiMn component system design, appropriately reduces the content of corrosion-resistant alloy elements, and reduces the production cost.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of metallurgical plate production, and particularly relates to a production method of thin-gauge weather-resistant steel for photovoltaic supports. BACKGROUND

[0002] Atmospheric corrosion resistant steel (i.e. weather-resistant steel) refers to a low-alloy steel with good atmospheric corrosion resistance, which is prepared by adding a certain amount of Cu, P, C or Ni, Mo, Nb, Ti and other alloy elements in the steel. In the industrial and rural atmospheric environment, the weather-resistant steel has excellent atmospheric corrosion resistance and other properties because a dense and stable oxidation protective film is formed on the surface of the base body, which hinders the entry of the corrosion medium. The rust layer formed by the corrosion of the base body surface of the plain carbon steel has a loose structure and micro-cracks, and cannot truly protect the base steel. SUMMARY

[0003] The purpose of the application is to provide a production method of thin-gauge weather-resistant steel for photovoltaic supports, which adopts a conventional CSiMn component system design, adds corrosion-resistant elements Cu, P and Cr, appropriately reduces the content of corrosion-resistant alloy elements, and reduces the production cost. The product is mainly used for the manufacture of paint-free photovoltaic supports.

[0004] To solve the above technical problems, the application adopts the following technical scheme:

[0005] The production method of the thin-gauge weather-resistant steel for photovoltaic supports comprises the following steps:

[0006] The smelting-continuous casting production process flow is: hot metal pretreatment-converter-LF refining-casting machine;

[0007] The hot rolling production process flow is: slab heating-high pressure water descaling-width setting press-E1R1 rough rolling mill rolling-E2R2 rough rolling mill rolling-flying shear-high pressure water descaling-F1-F7 finishing mill rolling-encryption laminar cooling-coiling-warehousing-sampling and inspection-weighing and packaging;

[0008] Among them:

[0009] The casting blank discharge temperature is 1240±20 DEG C, the final rolling temperature of the finishing mill is 890±10 DEG C, the cold speed is 10-20 DEG C / S, the hot rolled steel strip thickness is 1.8-2.5 mm; the cooling adopts laminar cooling equipment, the front dispersion cooling mode, and the coiling temperature is 650±10 DEG C;

[0010] The chemical composition of the thin-gauge weathering steel for the photovoltaic support has mass percentage of C: 0.06-0.08%, Si: 0.15-0.25%, Mn: 0.35-0.45%, P: 0.03-0.04%, S: ≤0.001%, Cu: 0.26-0.30%, Cr: 0.55-0.65%, Ti: 0.020-0.030%, and the rest is Fe and inevitable impurities.

[0011] Further, the chemical composition of the thin-gauge weathering steel for the photovoltaic support has mass percentage of C: 0.07%, Si: 0.20%, Mn: 0.38%, P: 0.035%, S: 0.004%, Cu: 0.28%, Cr: 0.56%, Ti: 0.021%, and the rest is Fe and inevitable impurities.

[0012] Further, the chemical composition of the thin-gauge weathering steel for the photovoltaic support has mass percentage of C: 0.07%, Si: 0.22%, Mn: 0.38%, P: 0.036%, S: 0.004%, Cu: 0.28%, Cr: 0.58%, Ti: 0.019%, and the rest is Fe and inevitable impurities.

[0013] Further, the chemical composition of the thin-gauge weathering steel for the photovoltaic support has mass percentage of C: 0.07%, Si: 0.20%, Mn: 0.39%, P: 0.033%, S: 0.003%, Cu: 0.28%, Cr: 0.59%, Ti: 0.019%, and the rest is Fe and inevitable impurities.

[0014] Further, the molten iron is pretreated by desulfurization, and the molten iron is dephosphorized and decarburized to obtain molten steel by adopting top and bottom combined blowing converter smelting, the converter smelting is blown with argon throughout, scrap steel is added into the converter, and the converter tapping temperature is 1620℃; then the molten steel after the converter smelting is subjected to LF furnace outer refining, the refining in-place temperature is ≥1560℃, the LF furnace outer refining is measured for temperature and the composition is finely adjusted; the slab continuous casting superheat is 25℃, and then the slab cleaning, slow cooling and continuous casting blank quality inspection are performed; the slab heating temperature is 1230℃, the heating time is 43min, and hot continuous rolling mill is adopted for rolling; the finish rolling temperature is 890℃, and the finished product thickness is 2mm; the laminar flow cooling adopts front dispersion cooling, the cooling speed is 14℃ / S, the steel strip temperature is reduced to 646℃ for coiling; and finally the product performance detection is performed.

[0015] Further, the molten iron is pretreated by desulphurization, and is smelted by top and bottom combined blowing converter to remove phosphorus and carbon to obtain molten steel, argon is blown in the whole process of converter smelting, scrap steel is added into the converter, and the tapping temperature of the converter is 1623℃; then the molten steel after converter smelting is refined by LF external refining, the in-place temperature of refining is greater than or equal to 1560℃, temperature measurement and component fine adjustment are carried out in the LF external refining; the slab continuous casting superheat is 25℃, then slab cleaning, slow cooling and continuous casting blank quality inspection are carried out; the slab heating temperature is 1235℃, the heating time is 45min, and hot continuous rolling mill is used for rolling; the finish rolling temperature of finish rolling is 893℃, the finished product thickness is 2mm; the laminar flow cooling adopts front dispersion cooling, the cooling speed is 14℃ / S, the steel strip temperature is reduced to 650℃ for coiling; finally, product performance detection is carried out.

[0016] Further, the molten iron is pretreated by desulphurization, and is smelted by top and bottom combined blowing converter to remove phosphorus and carbon to obtain molten steel, argon is blown in the whole process of converter smelting, scrap steel is added into the converter, and the tapping temperature of the converter is 1623℃; then the molten steel after converter smelting is refined by LF external refining, the in-place temperature of refining is greater than or equal to 1560℃, temperature measurement and component fine adjustment are carried out in the LF external refining; the slab continuous casting superheat is 25℃, then slab cleaning, slow cooling and continuous casting blank quality inspection are carried out; the slab heating temperature is 1235℃, the heating time is 45min, and hot continuous rolling mill is used for rolling; the finish rolling temperature of finish rolling is 893℃, the finished product thickness is 2mm; the laminar flow cooling adopts front dispersion cooling, the cooling speed is 14℃ / S, the steel strip temperature is reduced to 650℃ for coiling; finally, product performance detection is carried out.

[0017] Compared with the prior art, the beneficial technical effects of the present application are:

[0018] The metallographic microstructure of the present application is mainly ferrite and contains a small amount of pearlite. The grain size is between 11 and 11.5. The 500MPa grade hot-rolled high-strength structural steel produced by the method provided by the present application meets the relevant technical standard requirements of automobile factories in terms of surface quality and performance indicators, and meets the use requirements of relevant automobile factories. The mechanical properties and process properties meet the relevant standards and user requirements. At the same time, the alloy cost is low, the preparation method is simple, and it is suitable for industrial production. BRIEF DESCRIPTION OF DRAWINGS

[0019] The present application will be further described below in conjunction with the drawings.

[0020] Figure 1 The microstructure diagram of the present application is shown in Figure 1. DETAILED DESCRIPTION

[0021] The present application will be further described below in conjunction with the drawings.

[0022] Example 1

[0023] The hot metal is desulphurized pretreatment, using top and bottom combined blowing converter smelting to make the hot metal decarburization, dephosphorization to obtain the molten steel, argon blowing in the whole process of converter smelting, scrap steel is added into the converter, the converter tapping temperature is 1630℃. Then the molten steel after converter smelting is subjected to LF furnace refining, the refining in place temperature is ≥1560℃, the temperature measurement and composition fine adjustment are carried out in the LF furnace refining, the chemical composition of the LF refining for the caster is shown in Table 1, calcium treatment is carried out after the LF treatment, and the soft blowing time is ensured to be more than 8 minutes after the calcium treatment. The slab continuous casting superheat is 25℃, then the slab cleaning, slow cooling and continuous casting blank quality inspection are carried out. The slab heating temperature is 1230℃, the heating time is 205min, the high pressure water phosphorus removal is carried out after the heated slab. The width is determined by the fixed width press, 2 rack rough rolling and 7 rack CVC finishing rolling are adopted. The finishing rolling final rolling temperature is 890℃, the finished product thickness is 7mm. The laminar cooling adopts front dispersion cooling, the steel strip temperature is reduced to 590℃ for coiling, and finally the product performance detection is carried out.

[0024] Example 2

[0025] The hot metal is desulphurized pretreatment, using top and bottom combined blowing converter smelting to make the hot metal decarburization, dephosphorization to obtain the molten steel, argon blowing in the whole process of converter smelting, scrap steel is added into the converter, the converter tapping temperature is 1630℃. Then the molten steel after converter smelting is subjected to LF furnace refining, the refining in place temperature is ≥1560℃, the temperature measurement and composition fine adjustment are carried out in the LF furnace refining, the chemical composition of the LF refining for the caster is shown in Table 1, calcium treatment is carried out after the LF treatment, and the soft blowing time is ensured to be more than 8 minutes after the calcium treatment. The slab continuous casting superheat is 25℃, then the slab cleaning, slow cooling and continuous casting blank quality inspection are carried out. The slab heating temperature is 1230℃, the heating time is 205min, the high pressure water phosphorus removal is carried out after the heated slab. The width is determined by the fixed width press, 2 rack rough rolling and 7 rack CVC finishing rolling are adopted. The finishing rolling final rolling temperature is 890℃, the finished product thickness is 7mm. The laminar cooling adopts front dispersion cooling, the steel strip temperature is reduced to 590℃ for coiling, and finally the product performance detection is carried out.

[0026] Example 3

[0027] The molten iron is pretreated by desulphurization, and the molten iron is decarburized and dephosphorized by top and bottom combined blowing converter smelting to obtain molten steel. The converter smelting is performed by blowing argon, scrap steel is added into the converter, and the converter tapping temperature is 1628℃. Then the molten steel after the converter smelting is subjected to LF furnace external refining, the refining in-place temperature is ≥1560℃, the temperature and composition are adjusted in the LF furnace external refining, the chemical composition of the LF furnace external refining for the casting machine is shown in Table 1, calcium treatment is performed after the F treatment, and the soft blowing time after the calcium treatment is ensured to be more than 8 minutes. The slab continuous casting superheat is 28℃, and then slab cleaning, slow cooling and continuous casting blank quality inspection are performed. The slab heating temperature is 1233℃, the heating time is 205 min, the heated slab is subjected to high-pressure water dephosphorization, the width of the slab is determined by a fixed-width press, 2-stand rough rolling and 7-stand CVC finishing rolling are adopted. The finishing rolling final rolling temperature is 896℃, and the finished product thickness is 7mm. The laminar flow cooling is performed by front dispersion cooling, the steel strip temperature is reduced to 593℃ for coiling, and finally product performance detection is performed.

[0028] Table 1 Chemical composition (wt%) of the steel coils of Examples 1-3 of the present application

[0029] Examples C Si Mn P S Alt Nb Ti 1 0.07 0.10 0.77 0.016 0.003 0.029 0.032 0.036 2 0.07 0.12 0.75 0.018 0.004 0.027 0.030 0.036 3 0.07 0.10 0.77 0.015 0.003 0.035 0.033 0.036

[0030] The steel coils of Examples 1-3 of the present application are subjected to mechanical property inspection, and the inspection results are shown in Table 2.

[0031] Table 2 Mechanical properties of the steel coils of Examples 1-3 of the present application

[0032]

[0033]

[0034] As shown in the data in Table 2, the mechanical properties and process properties of the 500MPa grade hot-rolled high-strength structural steel produced according to the method provided by the present application meet the requirements of the agreement signed with the user.

[0035] The above-described examples only describe the preferred modes of the present application, and do not limit the scope of the present application. Without departing from the design spirit of the present application, various modifications and improvements of the technical solutions of the present application made by those skilled in the art shall fall within the protection scope determined by the claims of the present application.

Claims

1. A method for producing a thin gauge weathering steel for photovoltaic racks, characterized by: Comprise: Smelting-continuous casting production process: hot metal pretreatment-converter-LF refining-casting machine; Hot rolling production process: slab heating-high pressure water descaling-width setting press-E1R1 rough rolling mill rolling-E2R2 rough rolling mill rolling-flying shear-high pressure water descaling-F1-F7 finishing rolling mill rolling-encryption laminar cooling-coiling-warehousing-sampling, inspection-weighing, packaging; Wherein: The casting blank tapping temperature is 1240±20℃, the finishing rolling temperature is 890±10℃, the cold speed is 10-20℃ / S, the hot rolled steel strip thickness is 1.8-2.5mm; the cooling adopts laminar cooling equipment, the front dispersion cooling mode, and the coiling temperature is 650±10℃; The mass percentage of the chemical composition of the thin gauge weathering steel for photovoltaic support is: C: 0.06-0.08%, Si: 0.15-0.22%, Mn: 0.35-0.39%, P: 0.03-0.04%, S: ≤0.001%, Cu: 0.26-0.30%, Cr: 0.55-0.59%, Ti: 0.020-0.030%, and the rest is Fe and inevitable impurities.

2. The method of producing thin gauge weathering steel for photovoltaic racks according to claim 1, characterized in that: The hot metal is subjected to desulfurization pretreatment, and the hot metal is subjected to dephosphorization and decarburization by adopting top and bottom combined blowing converter smelting to obtain molten steel, argon is blown throughout the converter smelting process, scrap steel is added into the converter, and the converter tapping temperature is 1620℃; then the molten steel after converter smelting is subjected to LF external refining, the refining in-place temperature is greater than or equal to 1560℃, temperature measurement and composition fine adjustment are performed in the LF external refining; the slab continuous casting superheat is 25℃, then slab cleaning, slow cooling and continuous casting blank quality inspection are performed; the slab heating temperature is 1230℃, the heating time is 43min, hot continuous rolling mill is adopted for rolling; the finishing rolling final rolling temperature is 890℃, the finished product thickness is 2mm; the laminar cooling adopts front dispersion cooling, the cooling speed is 14℃ / S, the steel strip temperature is reduced to 646℃ for coiling; finally, product performance detection is performed.

3. The method of producing thin gauge weathering steel for photovoltaic racks according to claim 1, characterized in that: The hot metal is subjected to desulfurization pretreatment, and the hot metal is subjected to dephosphorization and decarburization by adopting top and bottom combined blowing converter smelting to obtain molten steel, argon is blown throughout the converter smelting process, scrap steel is added into the converter, and the converter tapping temperature is 1623℃; then the molten steel after converter smelting is subjected to LF external refining, the refining in-place temperature is greater than or equal to 1560℃, temperature measurement and composition fine adjustment are performed in the LF external refining; the slab continuous casting superheat is 25℃, then slab cleaning, slow cooling and continuous casting blank quality inspection are performed; the slab heating temperature is 1235℃, the heating time is 45min, hot continuous rolling mill is adopted for rolling; the finishing rolling final rolling temperature is 893℃, the finished product thickness is 2mm; the laminar cooling adopts front dispersion cooling, the cooling speed is 14℃ / S, the steel strip temperature is reduced to 650℃ for coiling; finally, product performance detection is performed.

4. The method of producing thin-gauge weathering steel for photovoltaic racks according to claim 1, characterized in that: The molten iron is desulfurized and pretreated, and is smelted by top and bottom combined blowing converter to remove phosphorus and carbon to obtain molten steel, argon is blown in the whole process of converter smelting, scrap steel is added into the converter, and the tapping temperature of the converter is 1633 ℃; then the molten steel after converter smelting is subjected to LF external refining, the in-place temperature is greater than or equal to 1560 ℃, temperature measurement and composition fine adjustment are carried out in the LF external refining; the slab continuous casting superheat is 20 ℃, then slab cleaning, slow cooling and continuous casting blank quality inspection are carried out; the slab heating temperature is 1250 ℃, the heating time is 49 min, and hot continuous rolling mill is used for rolling; the finish rolling temperature is 899 ℃, and the finished product thickness is 2 mm; the laminar cooling adopts front dispersion cooling, the cooling speed is 14 ℃ / S, the steel strip temperature is reduced to 653 ℃ for coiling; finally, product performance detection is carried out.

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