An enamel composition, a method for preparing an enamel composition, and a cooking appliance are provided. The enamel composition may include phosphorus pentoxide (P.sub.2O.sub.5) at 15 to 50 wt %; silicon dioxide (SiO.sub.2) at 10 to 20 wt %; boron oxide (B.sub.2O.sub.3) at 1 to 15 wt %; one or more of lithium oxide (Li.sub.2O), sodium oxide (Na.sub.2O), or potassium oxide (K.sub.2O) at 5 to 20 wt %; one or more of sodium fluoride (NaF), calcium fluoride (CaF.sub.2), or aluminum fluoride (AlF.sub.3) at 1 to 5 wt %; one or more of magnesium oxide (MgO), barium oxide (BaO), or calcium oxide (CaO) at 1 to 35 wt %; and one or more of titanium dioxide (TiO.sub.2), cerium dioxide (CeO.sub.2), molybdenum trioxide (MoO.sub.3), bismuth oxide (Bi.sub.2O.sub.3), or copper oxide (CuO) at 10 to 25 wt %, such that a heating time required for cleaning may be shortened and oil contaminants may be completely removed.

An enamel composition, a method for preparing an enamel composition, and a cooking appliance are provided. The enamel composition may include phosphorus pentoxide (P.sub.2O.sub.5) at 15 to 50 wt %; silicon dioxide (SiO.sub.2) at 10 to 20 wt %; boron oxide (B.sub.2O.sub.3) at 1 to 15 wt %; one or more of lithium superoxide (Li.sub.2O), sodium oxide (Na.sub.2O), or potassium oxide (K.sub.2O) at 5 to 20 wt %; one or more of sodium fluoride (NaF), calcium fluoride (CaF.sub.2), or aluminum fluoride (AlF.sub.3) at 1 to 5 wt %; one or more of magnesium oxide (MgO), barium oxide (BaO), or calcium oxide (CaO) at 1 to 35 wt %; and one or more of titanium dioxide (TiO.sub.2), cerium dioxide (CeO.sub.2), molybdenum trioxide (MoO.sub.3), bismuth oxide (Bi.sub.2O.sub.3), or copper oxide (CuO) at 10 to 25 wt %, such that a heating time required for cleaning may be shortened and oil contaminants may be completely removed.

An enamel composition, a method for preparing an enamel composition, and a cooking appliance are provided. The enamel composition may include phosphorus pentoxide (P.sub.2O.sub.5) at 15 to 50 wt %; silicon dioxide (SiO.sub.2) at 10 to 20 wt %; boron oxide (B.sub.2O.sub.3) at 1 to 15 wt %; one or more of lithium superoxide (Li.sub.2O), sodium oxide (Na.sub.2O), or potassium oxide (K.sub.2O) at 5 to 20 wt %; one or more of sodium fluoride (NaF), calcium fluoride (CaF.sub.2), or aluminum fluoride (AlF.sub.3) at 1 to 5 wt %; one or more of magnesium oxide (MgO), barium oxide (BaO), or calcium oxide (CaO) at 1 to 35 wt %; and one or more of titanium dioxide (TiO.sub.2), cerium dioxide (CeO.sub.2), molybdenum trioxide (MoO.sub.3), bismuth oxide (Bi.sub.2O.sub.3), or copper oxide (CuO) at 10 to 25 wt %, such that a heating time required for cleaning may be shortened and oil contaminants may be completely removed.

A coating composition may include a glass frit including Phosphorus Oxide (P.sub.2O.sub.5), Silicon Oxide (SiO.sub.2), Boron Oxide (B.sub.2O.sub.3), a group I-based metal oxide, Barium Oxide (BaO), Sodium Fluoride (NaF), Titanium Oxide (TiO2), Stannous Oxide (SnO), Zinc Oxide (ZnO), and an adhesion enhancement component. The P.sub.2O.sub.5 may be included by about 40 wt % to about 55 wt % based on a total weight of the glass frit. The SiO.sub.2 may be included by about 5 wt % to about 15 wt % based on the total weight of the glass frit. The B.sub.2O.sub.3 may be included by about 5 wt % to about 10 wt % based on the total weight of the glass frit. The group I-based metal oxide may be included by about 3 wt % to about 10 wt % based on the total weight of the glass frit. The ZnO may be included by about 10 wt % to about 25 wt % based on the total weight of the glass frit, and the TiO.sub.2 may be included by about 0.1 wt % to about 5 wt % based on the total weight of the glass frit.

A coating composition may include a glass frit including Phosphorus Oxide (P.sub.2O.sub.5), Silicon Oxide (SiO.sub.2), Boron Oxide (B.sub.2O.sub.3), a group I-based metal oxide, Barium Oxide (BaO), Sodium Fluoride (NaF), Titanium Oxide (TiO2), Stannous Oxide (SnO), Zinc Oxide (ZnO), and an adhesion enhancement component. The P.sub.2O.sub.5 may be included by about 40 wt % to about 55 wt % based on a total weight of the glass frit. The SiO.sub.2 may be included by about 5 wt % to about 15 wt % based on the total weight of the glass frit. The B.sub.2O.sub.3 may be included by about 5 wt % to about 10 wt % based on the total weight of the glass frit. The group I-based metal oxide may be included by about 3 wt % to about 10 wt % based on the total weight of the glass frit. The ZnO may be included by about 10 wt % to about 25 wt % based on the total weight of the glass frit, and the TiO.sub.2 may be included by about 0.1 wt % to about 5 wt % based on the total weight of the glass frit.

A method for heat-treating a component which consists of a metal alloy, in which or on which at least one surface section is coated with a glaze or enamel coating, includes heating the component to a heating temperature which at least equals a minimum quenching temperature, and quenching the component starting from a temperature which at least equals the minimum quenching temperature in order to produce a higher-strength microstructure in the component. The components can be heat-treated such that the glaze or enamel coating is reliably prevented from chipping. The glaze or enamel coating is pre-cooled to a pre-cooling temperature at least on its free surface prior to quenching, said pre-cooling temperature maximally corresponding to the temperature at which the glaze or enamel coating begins to soften, and wherein the cooling rate at which the glaze or enamel coating is cooled is lower than the cooling rate during quenching.

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).

The invention relates to removal from the working area of a dust and gas mixture produced by action of a processing tool on the material being processed. The present dust and gas valve is intended to be mounted in an apparatus for processing materials. The dust and gas valve comprises a casing adapted to accommodate a processing tool and to be connected to a system for aspirating the produced dust and gas mixture, and means for directing the dust and gas mixture into the casing. According to the invention said means comprises: a unit for directional supply of compressed air to the working area, and a dust and gas mixture flow guiding element having a lower surface disposed around the working area and streamlined for the dust and gas mixture flow.

The present invention provides methods for preparing or repairing a chemically-resistant coating such as a porcelain enamel on a metal substrate. One such method involves forming a ground coat on the substrate, cooling the substrate to substantially near ambient temperature, optionally by applying a heat source to cool the substrate slowly, followed by flame-spray depositing a coating material onto the softened ground coat. Then, the substrate is allowed to cool slowly so the chemically-resistant coating can form with less stress. Optionally, an induction coil is used to heat the substrate, both to form the ground coat and to slow the cooling of the substrate. Such methods allow for easier and faster repairs, and even in situ repairs of articles such as chemical reactor vessels, covers, baffles, thermowells, agitators, agitator shafts, pipes, heat exchangers, and storage tanks, as well as white goods such as ovens, stoves, washing machines, driers, in addition to bathtubs, sinks, and shower stalls, in addition to steel girders and steel reinforcing bars. Articles having a chemically-resistant coating also form a part of the invention.

The present invention provides methods for preparing or repairing a chemically-resistant coating such as a porcelain enamel on a metal substrate. One such method involves forming a ground coat on the substrate, cooling the substrate to substantially near ambient temperature, optionally by applying a heat source to cool the substrate slowly, followed by flame-spray depositing a coating material onto the softened ground coat. Then, the substrate is allowed to cool slowly so the chemically-resistant coating can form with less stress. Optionally, an induction coil is used to heat the substrate, both to form the ground coat and to slow the cooling of the substrate. Such methods allow for easier and faster repairs, and even in situ repairs of articles such as chemical reactor vessels, covers, baffles, thermowells, agitators, agitator shafts, pipes, heat exchangers, and storage tanks, as well as white goods such as ovens, stoves, washing machines, driers, in addition to bathtubs, sinks, and shower stalls, in addition to steel girders and steel reinforcing bars. Articles having a chemically-resistant coating also form a part of the invention.