Provided is a glass composition comprising a glass frit containing P.sub.2O.sub.5, BaO, ZnO, group I-based oxide and group II-based oxide, wherein the P.sub.2O.sub.5 is contained in an amount of 20 wt % to 55 wt % based on a total weight of the glass frit, wherein each of the BaO and ZnO is contained in an amount of 2 to 30% by weight based on the total weight of the glass frit, wherein the group I-based oxide is contained in an amount of 5 to 20% by weight based on the total weight of the glass frit, wherein the group II-based oxide is contained in an amount of 1 to 15% by weight based on the total weight of the glass frit.

A cooking apparatus including an enamel coating layer having an improved cleaning efficiency and a manufacturing method therefor are provided. The cooking apparatus includes a cooking compartment configured to accommodate a cooking object, a door configured to open and close the cooking compartment, and an enamel coating layer provided on a surface of the cooking compartment. The enamel coating layer includes, in percent (%) by weight of the entire composition, 5% or less (excluding 0%) of a silicon dioxide (SiO.sub.2), 10% to 20% of an aluminum oxide (Al.sub.2O.sub.3), 10% to 20% of a phosphorous pentoxide (P.sub.2O.sub.5), 5% to 15% of a rare earth oxide, and 5% to 10% of a ferric oxide (Fe.sub.2O.sub.3).

A cooking apparatus including an enamel coating layer having an improved cleaning efficiency and a manufacturing method therefor are provided. The cooking apparatus includes a cooking compartment configured to accommodate a cooking object, a door configured to open and close the cooking compartment, and an enamel coating layer provided on a surface of the cooking compartment. The enamel coating layer includes, in percent (%) by weight of the entire composition, 5% or less (excluding 0%) of a silicon dioxide (SiO.sub.2), 10% to 20% of an aluminum oxide (Al.sub.2O.sub.3), 10% to 20% of a phosphorous pentoxide (P.sub.2O.sub.5), 5% to 15% of a rare earth oxide, and 5% to 10% of a ferric oxide (Fe.sub.2O.sub.3).

An enamel composition, a method for preparing an enamel composition, and a cooking appliance are provided. The enamel composition may include 15 to 50 wt % of phosphorus pentoxide (P.sub.2O.sub.5); 5 to 20 wt % of one or more of lithium oxide (Li.sub.2O), sodium oxide (Na.sub.2O), or potassium oxide (K.sub.2O); 1 to 5 wt % of one or more of sodium fluoride (NaF), calcium fluoride (CaF.sub.2), or aluminum fluoride (AlF.sub.3); 1 to 35 wt % of one or more of magnesium oxide (MgO), barium oxide (BaO), or calcium oxide (CaO); and 5 to 30 wt % of one or more of manganese dioxide (MnO.sub.2), molybdenum trioxide (MoO.sub.3), bismuth oxide (Bi.sub.2O.sub.3), or nickel oxide (NiO). The enamel composition may be cleaned without being putting it into water.

The invention discloses a metal anticorrosive coating. The coating is an inorganic coating used for metal anticorrosion. This coating has a double-layer structure, including an outer enamel coating and an inner base oxide coating. Meanwhile, the content of the base metal oxide decreases from the inner layer to the outer layer, which causes the thermal expansion coefficient of the coating to increase from the inner layer to the outer layer, ensures that the overall thermal expansion coefficient of the coating is coordinate with various base metals. The composition of the outer layer enamel coating includes: by weight, 1-40 parts of silicon, 1-30 parts of sodium, 1-20 parts of potassium, 2-20 parts of calcium, 0.5-15 parts of fluorine, 0.3-10 parts of cobalt, 0.2-10 parts of nickel, 1-18 parts of boron, 0.5-10 parts of phosphorus, 0.1-8 parts of magnesium, and the rest is oxygen; the composition of the base oxide coating of the inner layer includes the base metal and oxygen. A preparation process of a double-layer dense metal anticorrosive coating formed by low-temperature sintering is also disclosed, including the following steps: 1) grinding; 2) preparation of mixture; 3) grinding; 4) high temperature reaction; 5) grinding; 6) coating; 7) sintering. The coating of the invention has the advantages of improving the corrosion resistance by more than 14 times, has a high ductility which can be coordinated with the reinforcing steel bar in tensile deformation, has a thermal expansion coefficient gradient which can be applied to different metals and different types of the same metal.

The invention discloses a metal anticorrosive coating. The coating is an inorganic coating used for metal anticorrosion. This coating has a double-layer structure, including an outer enamel coating and an inner base oxide coating. Meanwhile, the content of the base metal oxide decreases from the inner layer to the outer layer, which causes the thermal expansion coefficient of the coating to increase from the inner layer to the outer layer, ensures that the overall thermal expansion coefficient of the coating is coordinate with various base metals. The composition of the outer layer enamel coating includes: by weight, 1-40 parts of silicon, 1-30 parts of sodium, 1-20 parts of potassium, 2-20 parts of calcium, 0.5-15 parts of fluorine, 0.3-10 parts of cobalt, 0.2-10 parts of nickel, 1-18 parts of boron, 0.5-10 parts of phosphorus, 0.1-8 parts of magnesium, and the rest is oxygen; the composition of the base oxide coating of the inner layer includes the base metal and oxygen. A preparation process of a double-layer dense metal anticorrosive coating formed by low-temperature sintering is also disclosed, including the following steps: 1) grinding; 2) preparation of mixture; 3) grinding; 4) high temperature reaction; 5) grinding; 6) coating; 7) sintering. The coating of the invention has the advantages of improving the corrosion resistance by more than 14 times, has a high ductility which can be coordinated with the reinforcing steel bar in tensile deformation, has a thermal expansion coefficient gradient which can be applied to different metals and different types of the same metal.

Induction heating facilitated coating systems and processes for pipes overcome corrosion and erosion of the pipes at extreme temperatures and pressures in applications including oil and gas downhole tubulars and pipelines as well as processing facilities. Being based on vitreous fused inorganic compounds, the present invention achieves very high corrosion resistance at remarkably modest cost. Attractive economics and immunity to chlorides and moisture permeation at extreme concentrations and temperatures also make it well suited to desalination plants and potable water piping applications. Due to its extreme temperature resistance, it also is very well suited for geothermal wells. Additionally, due to its characteristic smooth durable surface, the present invention is ideally suited for applications involving the opposite of corrosion, namely scaling problems, such as fouling in sewage systems and scale buildup in heavy oil wells.

Induction heating facilitated coating systems and processes for pipes overcome corrosion and erosion of the pipes at extreme temperatures and pressures in applications including oil and gas downhole tubulars and pipelines as well as processing facilities. Being based on vitreous fused inorganic compounds, the present invention achieves very high corrosion resistance at remarkably modest cost. Attractive economics and immunity to chlorides and moisture permeation at extreme concentrations and temperatures also make it well suited to desalination plants and potable water piping applications. Due to its extreme temperature resistance, it also is very well suited for geothermal wells. Additionally, due to its characteristic smooth durable surface, the present invention is ideally suited for applications involving the opposite of corrosion, namely scaling problems, such as fouling in sewage systems and scale buildup in heavy oil wells.

An enamel composition, a method for preparing an enamel composition, and a cooking appliance are provided. The enamel composition may include 15 to 50 wt % of phosphorus pentoxide (P.sub.2O.sub.5); 5 to 20 wt % of one or more of lithium oxide (Li.sub.2O), sodium oxide (Na.sub.2O), or potassium oxide (K.sub.2O); 1 to 5 wt % of one or more of sodium fluoride (NaF), calcium fluoride (CaF.sub.2), or aluminum fluoride (AlF.sub.3); 1 to 35 wt % of one or more of magnesium oxide (MgO), barium oxide (BaO), or calcium oxide (CaO); and 5 to 30 wt % of one or more of manganese dioxide (MnO.sub.2), molybdenum trioxide (MoO.sub.3), bismuth oxide (Bi.sub.2O.sub.3), or nickel oxide (NiO). The enamel composition may be cleaned without being putting it into water.

The present invention is aimed at providing an unprecedented novel electrostatic powder coating material. Provided is an unprecedented electrostatic powder coating material capable of forming a heat-resistant coating film, wherein the electrostatic powder coating material contains at least glass particles (A) that soften at a baking temperature and glass particles (B) that do not soften at the baking temperature.