Abstract: There is provided a nitrided layer repair method in which a molten metal is pressurized and solidified, and thus a nitrided layer formed on a cavity surface of a mold used to form a casting object is repaired. In the nitrided layer repair method, a nitriding source is applied to the cavity surface, and the cavity surface of the mold is nitrided by heating and pressurizing the cavity surface using the molten metal.

Abstract: There is provided a nitrided layer repair method in which a molten metal is pressurized and solidified, and thus a nitrided layer formed on a cavity surface of a mold used to form a casting object is repaired. In the nitrided layer repair method, a nitriding source is applied to the cavity surface, and the cavity surface of the mold is nitrided by heating and pressurizing the cavity surface using the molten metal.

Abstract: [Task] There is provided a mold release agent for forming a water glass-containing sand mold with high release properties which can prevent attachment of a water glass to a flask and the accumulation of the water glass on the flask in the formation of the sand mold when using the water glass as a binder. [Solution] The mold release agent for forming the water glass-containing sand mold is structured to contain an organic compound, the organic compound having a proton-donating functional group that reacts with the water glass to produce silicon dioxide. The water glass contained in a raw material for the sand mold reacts with the proton-donating functional group contained in the mold release agent so as to produce silicon dioxide. Since silicon dioxide has no adhesion, it can prevent that the attachment (fixing) of the water glass contained in a formed sand mold to the flask and the accumulation of the water glass on the flask.

Abstract: [Task] There is provided a mold release agent for forming a water glass-containing sand mold with high release properties which can prevent attachment of a water glass to a flask and the accumulation of the water glass on the flask in the formation of the sand mold when using the water glass as a binder. [Solution] The mold release agent for forming the water glass-containing sand mold is structured to contain an organic compound, the organic compound having a proton-donating functional group that reacts with the water glass to produce silicon dioxide. The water glass contained in a raw material for the sand mold reacts with the proton-donating functional group contained in the mold release agent so as to produce silicon dioxide. Since silicon dioxide has no adhesion, it can prevent that the attachment (fixing) of the water glass contained in a formed sand mold to the flask and the accumulation of the water glass on the flask.

Abstract: An object is to propose a mold release agent improving the state of a mold surface by repeating casting cycle so as to extend the life of the metal mold actively, and a casting method using the mold release agent. A water-soluble mold release agent applied on a mold surface of a metal mold contains organic acid or organic acid salt which is reducing and ligand, wherein concentration of a total thereof is not less than 0.01 wt % in using concentration and is not more than a fixed concentration which is stability limit of emulsion of the mold release agent in undiluted concentration. Construction weight ratio of the organic acid or organic acid salt which is reducing and the ligand is in the range from 99/1 to 30/70.

Abstract: Vitreous, algae growing materials, release stably ferrous ions, over long periods of time. The duration of ion release can be controlled as desired by adjusting the particle size of the materials. The vitreous, algae growing, materials can be converted into porous forms or fabricated into at least parts of structures. The vitreous, algae growing, materials consist essentially of 15 to 50 weight percent SiO2, 1 to 35 weight percent either or both of Na2O and K2O, 30 to 70 weight percent B2O3, and 1 to 40 weight prercent of either or both of FeO and Fe2O3. Increasing the content of boron facilitates the release of ferrous ions from the vitreous, algae growing, materials.

Abstract: A release agent for green sand mold forming contains a hydrocarbon oil as the main lubrication component. The release agent contains a surface active agent as a dispersant and an anion surface active agent and/or a strong basic amine as a wettability improving agent as essential components besides the hydrocarbon oil. The release agent is used in a form of oil-in-water type emulsion by diluting it with water. Since it is possible to dilute the release agent with water, the release agent occupies less capacity during storage and transportation, and since the release agent can increase the water to the hydrocarbon oil ratio of the composition at application, it contributes to improvements in resource saving and safety against fire.