Process for the production of a glass-lined enamel

Abstract

The present application belongs to the technical field of glass lining enamel, and particularly relates to a production process of glass lining enamel. The glass lining enamel formula of the present application is composed of the following components in mass fraction: 34-40 parts of silicon dioxide, 12-18 parts of boron oxide, 5.5-10 parts of diaphosphorus pentoxide, 12-15 parts of aluminum oxide, 2-4 parts of sodium fluorosilicate, 1.5-3 parts of titanium dioxide, 10-15 parts of sodium oxide, 3-5 parts of potassium oxide, 3-8 parts of calcium oxide, 1-2 parts of nickel oxide and 0.5-1 part of cobalt oxide. The present application reduces the melting temperature and sintering temperature by adjusting the components of the existing technology, so that the sintered glass lining enamel has a compact structure network, good chemical corrosion resistance, and the toughening auxiliary agent forms a physical barrier to hinder crack propagation in the glass lining enamel structure network, so as to reduce the porosity and improve the mechanical properties and thermal shock resistance of the glass lining enamel.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of glass lining enamel, and particularly relates to a production process of glass lining enamel. BACKGROUND

[0002] The glass lining enamel is a composite material formed by spraying the enamel material to the surface of the carbon steel body and adhering to the surface of the carbon steel body through 860-950 DEG C multiple sintering phase transition. The glass lining enamel has a stable irregularly arranged network structure composed of silicon oxygen (or boron oxygen, phosphorus oxygen) polyhedron, which makes the exchange of dissolved oxygen and non-bridge oxygen difficult, and thus has excellent oxidation resistance and corrosion resistance.

[0003] The scale explosion of the glass lining equipment is a phenomenon that the enamel layer produces fish scale-shaped fragments, and once the scale explosion occurs, it means that the glass lining equipment is scrapped. During the glass lining process of the glass lining enamel, the over-high glass lining temperature and the over-long holding time can cause the redissolution and growth of the second phase particles in the steel substrate, reduce the hydrogen traps, and reduce the anti-scale explosion performance. In order to reduce the reduction of the anti-scale explosion performance of the glass lining equipment in the glass lining process, it is necessary to research the glass lining enamel with low sintering temperature and high adhesion.

[0004] The Chinese invention patent with the publication number CN117966163B discloses a glass lining enamel improved based on calcium silicate and a preparation method thereof, which comprises the following steps: S1. weighing; S2. enamel preparation; S3. stirring; S4. spraying; S5. standing; S6. firing: placing the steel substrate after standing into a muffle firing furnace for programmed temperature rising and falling, and firing for 30-40 min after reaching the highest temperature of 880 DEG C to obtain the glass lining enamel; the invention successfully prepares a glass lining with high toughness, high bending strength and high hardness by adding a proper amount of calcium silicate solid powder in the glass lining preparation process and strictly controlling the calcination process, and the glass lining also has the advantages of high corrosion resistance and low porosity, and the improvement of the existing glass lining preparation process has certain guiding value.

[0005] The Chinese invention patent with the publication number CN116282924B discloses a low-temperature enamel composition, which is composed of the following raw materials in percentage: quartz 10-20%, potassium feldspar 10-20%, borax 25-35%, soda ash 7-17%, sodium nitrate 2-12%, potassium nitrate 5-15%, calcium chloride 2-12%, zirconium phosphate 0.5-5%, vanadium pentoxide 1-10%, and mixed fluxing agent 30-40%. The mixed fluxing agent is composed of the following raw materials in percentage: K2O 18-25%, Na2O 12-15%, TiO2 11-14%, B2O3 7-11%, Li2O 1-4%, P2O5 1-5%, Al2O3 1-5%, CaO 6-10%, F 4-8%, SrO 8-13%, and SiO2 9-14%. Through the above technical solution, the gloss and adhesion strength of the enamel are improved, and the harmful substances in the enamel are also reduced.

[0006] However, the prior art has the technical problem of not further improving the enamel formula to reduce the sintering temperature and improve the thermal shock resistance. SUMMARY

[0007] The purpose of the present application is to provide a production process of enamel for glass lining, which solves the technical problem of not further improving the enamel formula to reduce the sintering temperature and improve the thermal shock resistance in the prior art.

[0008] In order to achieve the above-mentioned purpose, the present application adopts the following technical solution:

[0009] An enamel formula for glass lining, which comprises an enamel powder and a toughening auxiliary agent, the enamel powder is composed of the following components in mass fraction: silicon dioxide 34-40 parts, boron oxide 12-18 parts, phosphorus pentoxide 5.5-10 parts, aluminum oxide 12-15 parts, sodium fluosilicate 2-4 parts, titanium dioxide 1.5-3 parts, sodium oxide 10-15 parts, potassium oxide 3-5 parts, calcium oxide 3-8 parts, nickel oxide 1-2 parts, and cobalt oxide 0.5-1 part.

[0010] The toughening auxiliary agent is prepared by mixing porous mullite fibers, cerium oxide powder, and bentonite in a mass ratio of 3:1-2:1, and the mass ratio of the enamel powder to the toughening auxiliary agent is 100:1-3.

[0011] A production process of enamel for glass lining, which comprises the following steps:

[0012] S1, after weighing each component of the enamel powder, pour it into a ball mill for ball milling, and sieve to obtain a mixed powder;

[0013] S2, put the mixed powder into a crucible furnace to heat and smelt, and obtain a melt material; after the melt material is detected to be qualified, add deionized water to quench the melt material to obtain a porcelain enamel block; put the porcelain enamel block and a toughening auxiliary agent into a ball mill to grind, and then add deionized water to obtain a porcelain enamel glaze material after sieving;

[0014] S3, spray the porcelain enamel glaze material on the surface of the pretreated metal substrate, dry by heating, sinter at high temperature, and then test the performance of the finished product after cooling to obtain a porcelain enamel product.

[0015] Preferably, the grinding in S1 is performed for 4-6 hours, and the sieving is performed through a 100-200 mesh sieve.

[0016] Preferably, in S2, the heating is performed at a rate of 15-20 ℃ / min to 800-950 ℃ for 8-10 hours, the grinding is performed for 2-4 hours, and the sieving is performed through a 100-120 mesh sieve, and the bulk density of the porcelain enamel glaze material is 1.65-1.75 g / mL.

[0017] Preferably, in S2, the chemical composition of the melt material is detected by chemical analysis to determine whether it meets the range specified in the enamel porcelain enamel formula.

[0018] Preferably, in S3, the pretreatment process of the metal substrate includes surface grinding, sandblasting, cleaning, and drying.

[0019] Preferably, in S3, the sandblasting parameters are set as follows: the sandblasting air pressure is 0.5-0.6 MPa, the spraying distance is 80-120 mm, the spraying angle is 50-70°, the sandblasting time is 20-60 s, and the average roughness Ra of the metal substrate after sandblasting is 5-8 μm.

[0020] Preferably, in S3, the heating is performed to dry and remove water at 100-150 ℃, the heating is performed at a rate of 15-20 ℃ / min to 530-550 ℃ for 20-40 min, and the thickness of the enamel porcelain enamel layer after sintering is 0.8-1.8 mm.

[0021] Preferably, in S3, after the enamel porcelain enamel is sintered, the surface of the enamel layer is tested to determine whether it is flat, the number of impurities on the surface of the enamel porcelain enamel per square meter should not exceed three, and the area of each impurity should be less than 4 mm 2 , and there should be no cracks, scale explosion, peeling, and deformation surface defects. If the above surface defects exist, the enamel porcelain enamel needs to be re-melted and re-sintered.

[0022] Preferably, the preparation method of the toughening auxiliary agent comprises the following steps:

[0023] S11, polyaluminum chloride is added into deionized water, acid silica sol is added dropwise, and stirring is performed under temperature rise to prepare a mullite gel precursor, the mullite gel precursor and polyvinyl alcohol template agent are added into paraffin oil to perform homogenizing stirring to prepare a spinning solution, the spinning solution is added into a syringe to perform electrospinning, and calcination and cooling are performed to prepare a porous mullite fiber;

[0024] S12, the porous mullite fiber, cerium oxide powder and bentonite are mixed and ball milled to prepare a toughening auxiliary agent.

[0025] Preferably, in S11, the acid silica sol has a pH of 2-3.5 and a silica content of 25-35 wt%.

[0026] Preferably, in S11, the molar ratio of aluminum ions to silicon ions in the polyaluminum chloride and the acid silica sol is 3:1-2, the mass ratio of the mullite gel precursor, the polyvinyl alcohol and the paraffin oil is 50-60:5-10:20-25, and electrospinning is performed at room temperature under a voltage of 15-20 kV and a perfusion speed of 1-5 mL / h.

[0027] Preferably, in S11, stirring is performed at 60-70 DEG C for 4-6 h, and calcination is performed at 1200-1400 DEG C for 1-2 h to remove the template agent.

[0028] Preferably, in S12, ball milling is performed for 2-4 h, the porous mullite fiber has an average diameter of 5-9 μm and an average length of 20-50 μm, and the cerium oxide powder has an average particle size of 30-60 μm.

[0029] As described above, due to the adoption of the above technical solutions, the present application has the following beneficial effects:

[0030] 1. The enamel enamel formula of the present application comprises enamel powder and a toughening auxiliary agent, the enamel powder is composed of the following components in mass parts: 34-40 parts of silicon dioxide, 12-18 parts of boron oxide, 5.5-10 parts of diaphosphorus pentoxide, 12-15 parts of aluminum oxide, 2-4 parts of sodium fluorosilicate, 1.5-3 parts of titanium dioxide, 10-15 parts of sodium oxide, 3-5 parts of potassium oxide, 3-8 parts of calcium oxide, 1-2 parts of nickel oxide and 0.5-1 part of cobalt oxide, and belongs to a borosilicate and phosphate composite system enamel. The present application reduces the melting temperature and the sintering temperature by adjusting the components of the enamel of the prior art. The silicon dioxide and the boron oxide form a borosilicate skeleton main network, and the diaphosphorus pentoxide modifier is added to adjust the network structure, so that the enamel structure network prepared by sintering is dense and has good chemical corrosion resistance. The addition of the toughening auxiliary agent forms a physical barrier that hinders crack propagation in the enamel structure network to improve the mechanical properties and thermal shock resistance of the enamel.

[0031] 2. The toughening agent of this invention is prepared by mixing porous mullite fiber, cerium oxide powder and bentonite. As an additive, porous mullite fiber cannot completely melt and participate in chemical reactions to enter the structural network in a short time. Thus, it is embedded in the enamel as a reinforcing phase in its original crystalline state, thereby improving the toughness of the enamel. The porous structure increases the number of micropores in the enamel by constructing internal pores, thereby improving the enamel's resistance to damage under load and thermal shock conditions. Bentonite improves the suspension stability of the enamel and extends the processing time of the enamel. Cerium oxide refines the grains through a crystallization reaction during the sintering process of the enamel, reduces defects, enhances adhesion, and improves the mechanical properties of the enamel. Detailed Implementation

[0032] The technical solutions in the embodiments of the present invention will be clearly and completely described below. 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 skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] The metal matrix involved in this invention is low-carbon aluminum-killed steel, and the specific elemental contents are as follows: carbon 0.10%, manganese 0.35%, silicon 0.02%, phosphorus 0.015%, sulfur 0.02%, aluminum 0.05%, copper, nickel, chromium and molybdenum total 0.70%, and the balance is iron.

[0034] The pretreatment process of the metal substrate in this invention is as follows: the surface of the metal substrate is polished to remove impurities, the polishing depth is 0.05~0.1mm, the sandblasting air pressure is 0.5MPa, the spraying distance is 80mm, the spraying angle is 60°, the sandblasting time is 20s, the average roughness Ra of the metal substrate after sandblasting is 6.25μm, it is cleaned with ethanol, and dried at 100℃ to obtain the pretreated metal substrate.

[0035] Example 1: A formulation for an enamel glaze in this example includes glaze powder and toughening additives. The glaze powder is composed of the following components by weight: 3.7 kg silicon dioxide, 1.75 kg boron oxide, 0.59 kg phosphorus pentoxide, 1.21 kg aluminum oxide, 0.22 kg sodium fluorosilicate, 0.28 kg titanium dioxide, 1.05 kg sodium oxide, 0.415 kg potassium oxide, 0.55 kg calcium oxide, 0.16 kg nickel oxide, and 0.075 kg cobalt oxide.

[0036] The toughening agent is prepared by mixing porous mullite fibers with an average diameter of 5 μm and an average length of 30 μm, cerium oxide powder with an average particle size of 50 μm and bentonite in a mass ratio of 3:2:1. The mass ratio of porcelain enamel powder to toughening agent is 97:3.

[0037] The production process of the enamel of the embodiment comprises the following steps:

[0038] S1, after weighing the components of the enamel powder, pour them into a ball mill and ball mill for 4h, and sieve through a 200-mesh sieve to obtain a mixed powder;

[0039] S2, put the mixed powder into a crucible furnace and heat it to 800℃ at a rate of 20℃ / min for 8h to obtain a melt material, after the material is detected to be qualified, quench it in deionized water to obtain an enamel block, put the enamel block and the toughening auxiliary agent into a ball mill and ball mill for 4h, sieve through a 120-mesh sieve, and then add deionized water to obtain an enamel glaze with a bulk density of 1.7g / mL;

[0040] S3, spray the enamel glaze on the surface of the pretreated metal substrate, dry it at a temperature of 150℃ to remove water, heat it to 530℃ at a rate of 20℃ / min and sinter it for 20min, the thickness of the enamel layer after sintering is 1.3mm, and the performance of the finished product is tested after cooling to obtain an enamel product.

[0041] The preparation method of the toughening auxiliary agent of the embodiment comprises the following steps:

[0042] S11, add 220g of polyaluminum chloride to 300mL of deionized water, add 66.7g of silica sol with a pH of 3.1 and a silicon dioxide content of 30wt% dropwise, heat to 60℃ and stir for 6h to obtain a mullite gel precursor, add 50g of the mullite gel precursor and 10g of a polyvinyl alcohol template agent to 25g of paraffin oil, homogenize and stir to obtain a spinning solution, load the spinning solution into a syringe, electrospun at a voltage of 15kV and a perfusion rate of 5mL / h at room temperature, calcine at 1300℃ for 2h to remove the template agent, and cool to obtain a porous mullite fiber;

[0043] S12, mix the porous mullite fiber, cerium oxide powder and bentonite, and ball mill for 2h to obtain a toughening auxiliary agent.

[0044] Embodiment 2, the formula of the enamel of the embodiment comprises an enamel powder and a toughening auxiliary agent, and the enamel powder is composed of the following components with the following mass: 4kg of silicon dioxide, 1.21kg of boron oxide, 0.86kg of phosphorus pentoxide, 1.45kg of aluminum oxide, 0.31kg of sodium fluorosilicate, 0.15kg of titanium dioxide, 1.05kg of sodium oxide, 0.36kg of potassium oxide, 0.38kg of calcium oxide, 0.15kg of nickel oxide, and 0.08kg of cobalt oxide;

[0045] The toughening auxiliary agent is prepared by mixing porous mullite fibers with an average diameter of 9 μm and an average length of 50 μm, cerium oxide powder with an average particle size of 30 μm, and bentonite at a mass ratio of 3:1:1, and the mass ratio of the enamel powder to the toughening auxiliary agent is 100:1.

[0046] The production process of the enamel of the embodiment comprises the following steps:

[0047] S1, after weighing the components of the enamel powder, the components are poured into a ball mill and ball milled for 6 h, and then sieved through a 100-mesh sieve to obtain a mixed powder;

[0048] S2, the mixed powder is placed in a crucible furnace and heated at a rate of 15 ℃ / min to 950 ℃ for 10 h to obtain a melt material, and then the melt material is quenched in deionized water to obtain an enamel block after detection, and then the enamel block and the toughening auxiliary agent are added into a ball mill and ball milled for 4 h, sieved through a 100-mesh sieve, and then added into deionized water to obtain an enamel frit with a bulk density of 1.65 g / mL;

[0049] S3, the enamel frit is sprayed on the surface of a pretreated metal substrate, dried at a temperature of 150 ℃ to remove water, and then sintered at a rate of 20 ℃ / min to 530 ℃ for 30 min, and then the enamel layer of the enamel has a thickness of 1.5 mm after sintering, and then the performance of the product is tested after cooling to obtain an enamel product.

[0050] The toughening auxiliary agent of the embodiment has the same preparation method as that of the embodiment 1.

[0051] In the embodiment 3, a formula of the enamel comprises an enamel powder and a toughening auxiliary agent, and the enamel powder is composed of the following components with the following mass: 3.7 kg of silicon dioxide, 1.5 kg of boron oxide, 0.85 kg of phosphorus pentoxide, 1.35 kg of aluminum oxide, 0.4 kg of sodium fluorosilicate, 0.25 kg of titanium dioxide, 1.08 kg of sodium oxide, 0.33 kg of potassium oxide, 0.42 kg of calcium oxide, 0.1 kg of nickel oxide, and 0.05 kg of cobalt oxide.

[0052] The toughening auxiliary agent is prepared by mixing porous mullite fibers with an average diameter of 6 μm and an average length of 35 μm, cerium oxide powder with an average particle size of 60 μm, and bentonite at a mass ratio of 3:1.5:1, and the mass ratio of the enamel powder to the toughening auxiliary agent is 100:2.

[0053] The production process of the enamel of the embodiment comprises the following steps:

[0054] S1, after weighing the components of the enamel powder, the components are poured into a ball mill and ball milled for 4 h, and then sieved through a 120-mesh sieve to obtain a mixed powder;

[0055] S2, the mixed powder is put into a crucible furnace to smelt for 10h at a rate of 17℃ / min to 850℃, the melt material is prepared, after the qualified material is taken for detection, it is water quenched in deionized water to prepare porcelain enamel blocks, the porcelain enamel blocks and the toughening auxiliary agent are added into a ball mill for ball milling for 4h, and then sieved through a 120 mesh sieve, and then deionized water is added to prepare a porcelain enamel glaze with a bulk density of 1.65g / mL;

[0056] S3, the porcelain enamel glaze is sprayed on the surface of the pretreated metal substrate, dried at a temperature of 120℃ to remove water, and then sintered at a rate of 17℃ / min to 55℃ for 40min, the thickness of the sintered enamel glass porcelain enamel layer is 0.9mm, and the performance of the finished product is checked after cooling to prepare an enamel glass porcelain enamel product.

[0057] The toughening auxiliary agent of the embodiment is different from that of embodiment 1 in that the molar ratio of aluminum ions to silicon ions of the porous mullite fiber is 3:1.5.

[0058] In embodiment 4, a formula of an enamel glass porcelain enamel includes a porcelain enamel powder and a toughening auxiliary agent, and the porcelain enamel powder is composed of the following components with the following mass: 3.6kg of silicon dioxide, 1.6kg of boron oxide, 0.55kg of diaphosphorus pentoxide, 1.37kg of aluminum oxide, 0.4kg of sodium fluorosilicate, 0.21kg of titanium dioxide, 1.1kg of sodium oxide, 0.31kg of potassium oxide, 0.59kg of calcium oxide, 0.2kg of nickel oxide, and 0.07kg of cobalt oxide.

[0059] The toughening auxiliary agent is prepared by mixing porous mullite fibers with an average diameter of 7μm and an average length of 40μm, cerium oxide powder with an average particle size of 40μm, and bentonite in a mass ratio of 3:1.2:1, and the mass ratio of the porcelain enamel powder to the toughening auxiliary agent is 100:3.

[0060] A production process of an enamel glass porcelain enamel of the embodiment includes the following steps:

[0061] S1, after the components of the porcelain enamel powder are weighed, they are added into a ball mill for ball milling for 5h, and then sieved through a 160 mesh sieve to prepare a mixed powder;

[0062] S2, the mixed powder is put into a crucible furnace to smelt for 9.5h at a rate of 16℃ / min to 860℃, the melt material is prepared, after the qualified material is taken for detection, it is water quenched in deionized water to prepare porcelain enamel blocks, the porcelain enamel blocks and the toughening auxiliary agent are added into a ball mill for ball milling for 3h, and then sieved through a 100 mesh sieve, and then deionized water is added to prepare a porcelain enamel glaze with a bulk density of 1.75g / mL;

[0063] S3, the enamel frit is sprayed on the surface of the pretreated metal substrate, dried at 150℃ to remove moisture, and sintered at a rate of 16℃ / min to 535℃ for 20min. The thickness of the sintered enamel layer is 1.6mm. After cooling, the performance of the finished product is tested to obtain the enamel product.

[0064] The difference between the toughening auxiliary agent of the present embodiment and that of embodiment 1 is that the molar ratio of aluminum ions and silicon ions of the porous mullite fiber is 3:2.

[0065] Embodiment 5, a formula of an enamel of the present embodiment, includes an enamel powder and a toughening auxiliary agent. The enamel powder is composed of the following components by mass: silicon dioxide 3.51kg, boron oxide 1.73kg, phosphorus pentoxide 0.76kg, aluminum oxide 1.23kg, sodium fluorosilicate 0.26kg, titanium dioxide 0.2kg, sodium oxide 1.37kg, potassium oxide 0.44kg, calcium oxide 0.41kg, nickel oxide 0.01kg, and cobalt oxide 0.08kg.

[0066] The toughening auxiliary agent is prepared by mixing porous mullite fibers with an average diameter of 9μm and an average length of 37.5μm, cerium oxide powder with an average particle size of 55μm, and bentonite in a mass ratio of 3:1.8:1. The mass ratio of the enamel powder and the toughening auxiliary agent is 100:2.5.

[0067] A production process of an enamel of the present embodiment includes the following steps:

[0068] S1, after weighing the components of the enamel powder, the components are poured into a ball mill and ball milled for 4-6h. The mixture is sieved through a 100-200 mesh sieve to obtain a mixed powder;

[0069] S2, the mixed powder is placed in a crucible furnace and heated at a rate of 15-20℃ / min to 800-950℃ for 8-10h to obtain a melt. After the melt is detected to be qualified, it is quenched in deionized water to obtain an enamel block. The enamel block and the toughening auxiliary agent are added to a ball mill and ball milled for 2-4h. The mixture is sieved through a 100-120 mesh sieve and then added to deionized water to obtain an enamel frit with a bulk density of 1.65-1.75g / mL;

[0070] S3, the enamel frit is sprayed on the surface of the pretreated metal substrate, dried at 150℃ to remove moisture, and sintered at a rate of 16℃ / min to 535℃ for 20min. The thickness of the sintered enamel layer is 1.6mm. After cooling, the performance of the finished product is tested to obtain the enamel product.

[0071] The preparation method of the toughening auxiliary agent of the present embodiment is the same as that of embodiment 1.

[0072] Comparative Example 1, the difference between this comparative example and Example 1 is that the components of the enamel powder are replaced by the following components: 4 kg of silicon dioxide, 0.5 kg of aluminum oxide, 1.4 kg of boron oxide, 1.581 kg of sodium oxide, 0.519 kg of potassium oxide, 0.28 kg of titanium dioxide, 0.2 kg of manganese oxide, 0.15 kg of nickel oxide, 0.07 kg of cobalt oxide, 0.4 kg of sodium fluorosilicate, and 0.2 kg of iron oxide. The enamel powder with the above-mentioned components is melted at 1000°C for 8 hours, and sintered at 800°C for 20 minutes to obtain the enamel for glass casting.

[0073] Comparative Example 2, the difference between this comparative example and Example 1 is that the components of the enamel powder are replaced by the following components: 6.4 kg of silicon dioxide, 0.2 kg of aluminum oxide, 0.4 kg of boron oxide, 1.12 kg of sodium oxide, 0.2 kg of potassium oxide, 0.8 kg of titanium dioxide, 0.35 kg of zirconium oxide, 0.2 kg of calcium oxide, 0.07 kg of cobalt oxide, 0.03 kg of manganese dioxide, and 0.03 kg of vanadium pentoxide. The enamel powder with the above-mentioned components is melted at 1200°C for 8 hours, and sintered at 900°C for 30 minutes to obtain the enamel for glass casting.

[0074] Comparative Example 3, the difference between this comparative example and Example 1 is that the toughening auxiliary agent is replaced by aluminum oxide powder.

[0075] Comparative Example 4, the difference between this comparative example and Example 1 is that the porous mullite fibers are not added to the toughening auxiliary agent.

[0076] Performance test

[0077] The expansion coefficients of the enamel for glass casting of Examples 1-5 and Comparative Examples 1 and 2 are tested according to GB / T 7991.7-2019 “Test methods for enamel layers Part 7: Determination of the average linear coefficient of thermal expansion”.

[0078] The impact resistance of the enamel for glass casting of Examples 1-5 and Comparative Examples 1-4 is tested according to GB / T 7990-2013 “Test methods for enamel layers Part 7: Determination of the average linear coefficient of thermal expansion”.

[0079] The thermal shock resistance of the enamel for glass casting of Examples 1-5 and Comparative Examples 3 and 4 is tested according to GB / T 11419-2008 “Determination method for temperature shock resistance of enamel cookware”.

[0080] The corrosion resistance of Examples 1-5 and Comparative Examples 1-4 is tested according to GB / T 7938-2013 “Determination of the corrosion resistance of enamel for glass casting to boiling acid and its vapors”. The acid solution is 30wt% sulfuric acid, and the soaking time is 1 day. The calculation formula is as follows:

[0081] ;

[0082] Δρ is the weight loss rate, unit: g / m 2 .

[0083] m0 is the mass before acid corrosion, unit: g;

[0084] m1 is the mass before acid corrosion, unit: g;

[0085] A is the area of acid corrosion, unit: m 2 .

[0086] The test results are shown in Table 1 as follows:

[0087] Table 1 Test results

[0088]

[0089] According to the data in the above table, the expansion coefficients of the enamel porcelain glazes prepared in Examples 1-5 are between 10.03-11.85, which are within the range of the expansion coefficient of low-carbon aluminum killed steel substrate. The enamel porcelain glaze of Comparative Example 1 is a borosilicate porcelain glaze, and the enamel porcelain glaze of Comparative Example 2 is a silicate porcelain glaze, both of which have expansion coefficients greater than the range of the expansion coefficient of low-carbon aluminum killed steel substrate, and the mismatch of the expansion coefficients easily leads to thermal stress concentration and induces cracking or peeling of the porcelain glaze. The impact strength of the enamel porcelain glazes prepared in Examples 1-5 is 19-21 kg*cm, and increases with the increase of the amount of the added toughening auxiliary agent, indicating that the enamel porcelain glaze prepared in the present application has excellent impact resistance.

[0090] Due to the decrease of the sintering temperature, the softening point temperature and the working temperature of the enamel porcelain glaze are both decreased, but the thermal shock temperature of the enamel porcelain glaze prepared in Examples 1-5 is 258-267℃, which is greater than the specified thermal resistance temperature of the chemical industry department, indicating that the physical barrier formed by the addition of the toughening auxiliary agent in the present application improves the thermal shock resistance of the enamel porcelain glaze, further indicating that the enamel porcelain glaze prepared in the present application has excellent thermal shock resistance. The weight loss rate of the enamel porcelain glaze prepared in Examples 1-5 is 0.112-0.156 g / m 2 , indicating that the enamel porcelain glaze prepared in the present application has excellent acid corrosion resistance.

[0091] The above is only a preferred specific embodiment of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can make equivalent substitutions or changes to the technical solution and the inventive concept of the present application within the technical range disclosed by the present application, which should be covered within the protection scope of the present application.

[0092] The preferred embodiments of the application disclosed above are only to facilitate the elucidation of the application. The preferred embodiments do not describe all the details of the application and limit the application to the specific embodiments. Obviously, many modifications and variations can be made in light of the teachings above. The description is chosen and described in order to provide the best illustration of the application and its practical application to those skilled in the art and to enable those skilled in the art to best utilize the application. The application is limited only by the claims and their full scope and equivalents.

Claims

1. A process for the production of a glass-lined enamel, characterized in that, It comprises the following steps: S1, after weighing the components of the raw materials for preparing the porcelain enamel block, pour them into a ball mill for ball milling, and sieve to obtain a mixed powder; S2, put the mixed powder into a crucible furnace for heating and smelting to obtain a melt, after taking the material and detecting that it is qualified, quench it in deionized water to obtain a porcelain enamel block, put the porcelain enamel block and the toughening auxiliary agent into a ball mill for ball milling, sieve, and then add them into deionized water to obtain a porcelain enamel frit; S3, spray the porcelain enamel frit on the surface of a pretreated metal substrate, heat and dry, high-temperature sinter, and then test the performance of the finished product after cooling to obtain an enamel porcelain enamel product; The raw materials for preparing the porcelain enamel block are composed of the following components in mass parts: Silicon dioxide 34-40 parts, boron oxide 12-18 parts, diaphosphoric anhydride 5.5-10 parts, aluminum oxide 12-15 parts, sodium fluosilicate 2-4 parts, titanium dioxide 1.5-3 parts, sodium oxide 10-15 parts, potassium oxide 3-5 parts, calcium oxide 3-8 parts, nickel oxide 1-2 parts, and cobalt oxide 0.5-1 part; The toughening auxiliary agent is prepared by mixing porous mullite fibers, cerium oxide powder, and bentonite in a mass ratio of 3:1-2:1, and the mass ratio of the porcelain enamel block and the toughening auxiliary agent is 100:1-3; The preparation method of the toughening auxiliary agent comprises the following steps: S11, add polyaluminum chloride into deionized water, drop acid silica sol, heat and stir to obtain a mullite gel precursor, add the mullite gel precursor and a polyvinyl alcohol template agent into paraffin oil for homogenizing and stirring to obtain a spinning solution, add the spinning solution into a syringe for electrospinning, remove the template agent by calcination, and cool to obtain porous mullite fibers; S12, mix the porous mullite fibers, cerium oxide powder, and bentonite for ball milling to obtain the toughening auxiliary agent; In S11, the pH of the acid silica sol is 2-3.5, the silicon dioxide content is 25-35 wt%, the molar ratio of aluminum ions and silicon ions in the polyaluminum chloride and the acid silica sol is 3:1-2, the mass ratio of the mullite gel precursor, the polyvinyl alcohol, and the paraffin oil is 50-60:5-10:20-25, the voltage is 15-20 kV, the perfusion speed is 1-5 mL / h, the stirring is carried out at room temperature for 4-6 h, and the template agent is removed by calcination at 1200-1400℃ for 1-2 h; in S12, the ball milling is carried out for 2-4 h, the average diameter of the porous mullite fibers is 5-9 μm, the average length is 20-50 μm, and the average particle size of the cerium oxide powder is 30-60 μm.

2. A process for the production of a glass-lined enamel according to claim 1, characterized in that, In S1, the ball milling is carried out for 4-6 h, and the sieving is carried out through a 100-200 mesh sieve; in S2, the heating is carried out at a rate of 15-20℃ / min to 800-950℃ for smelting for 8-10 h, the ball milling is carried out for 2-4 h, the sieving is carried out through a 100-120 mesh sieve, and the bulk density of the porcelain enamel frit is 1.65-1.75 g / mL.

3. A process for the production of a glass-lined enamel according to claim 1, characterized in that, The metal base pretreatment process in S3 includes surface polishing, sand blasting, cleaning and drying treatment, and the parameters of the sand blasting treatment are as follows: the sand blasting air pressure is 0.5-0.6 MPa, the spraying distance is 80-120 mm, the spraying angle is 50-70°, the sand blasting treatment time is 20-60 s, and the average roughness Ra of the metal base after the sand blasting treatment is 5-8 μm.

4. A process for the production of a glass-lined porcelain enamel according to claim 1, characterized in that, In S3, the temperature is increased to 100-150 DEG C for drying, the temperature is increased to 530-550 DEG C at a rate of 15-20 DEG C / min for sintering for 20-40 min, and the thickness of the enamel layer after sintering is 0.8-1.8 mm.

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