Abstract: Provided is a method for suppressing rear face oxidation and a lining structure, with which high airtightness and a great effect of suppressing rear face oxidation are obtained. The method for suppressing rear face oxidation of a carbon-containing refractory includes forming an adherent layer on a rear face of a carbon-containing refractory by applying an alkali metal silicate aqueous solution to the rear face and solidifying the alkali metal silicate aqueous solution. The alkali metal silicate aqueous solution contains an alkali metal oxide R2O (R is an alkali metal element) and SiO2 and has a molar ratio of SiO2 to the alkali metal oxide of 2.3 or more. The carbon-containing refractory is used at a high temperature of 400° C. or more and contains 1 mass % or more of carbon or a carbon compound.

Abstract: Provided is a method for suppressing rear face oxidation and a lining structure, with which high airtightness and a great effect of suppressing rear face oxidation are obtained. The method for suppressing rear face oxidation of a carbon-containing refractory includes forming an adherent layer on a rear face of a carbon-containing refractory by applying an alkali metal silicate aqueous solution to the rear face and solidifying the alkali metal silicate aqueous solution. The alkali metal silicate aqueous solution contains an alkali metal oxide R2O (R is an alkali metal element) and SiO2 and has a molar ratio of SiO2 to the alkali metal oxide of 2.3 or more. The carbon-containing refractory is used at a high temperature of 400° C. or more and contains 1 mass % or more of carbon or a carbon compound.

Abstract: Excellent characteristics concerning slag penetration-resistance, corrosion-resistance, and structural stability on usage of lining-refractory such as equipment for desiliconizing molten iron, a ladle for steel-making, a RH equipment are obtained. Unshaped refractories provide fine particles of under 0.75mm diameter, and aggregate of 0.75-10mm. Furthermore, the fine particles contain 10-35 mass % content of MgO, to the total mass % of the fine particles. Even furthermore, the sum total amount of MgO and Al2O3 is more than 90 mass %, to the total mass % of the fine particle. Additionally, such fine particles has 5-40 mass % of particles made of periclase-spinel, as a source of MgO, to the total mass % of the unshaped refractories. And, the aggregate comprises at least one selected from the group consisting of particles made of alumina and particles made of spinel.

Abstract: The object of the invention is to obtain an excellent characteristics concerning slag penetration-resistance, corrosion-resistance, and structural stability on usage of lining-refractory such as equipment for desiliconizing molten iron, a ladle for steel-making, a RH equipment and so forth. In order to solve a various problems that have a possibility to prohibiting the object of this invention, the unshaped refractories provide fine particles of under 0.75 mm diameter, and aggregate of 0.75-10 mm. Furthermore, the fine particles contain 10-35 mass % content of MgO, to the total mass % of the fine particles. Even furthermore, the sum total amount of MgO and Al2O3 is more than 90 mass %, to the total mass % of the fine particle. Additionally, such fine particles has 5-40 mass % of particles made of pericles-spinel, as a source of MgO, to the total mass % of the unshaped refractories.

Abstract: A graphite-containing monolithic refractory material comprises at least one component selected from alumina and alumina-magnesia spinel, which are divided into selected particle size regions, artificial graphite having a selected average particle size, and pitch powder. The refractory material may optionally comprise a selected amount of silicon carbide having a selected average particle size. The graphite-containing monolithic refractory material exhibits excellent casting workability at a low moisture content, and both excellent corrosion resistance and spalling resistance. The refractory material is suitable as a casting monolithic refractory material for lining a topedo ladle car.

Abstract: A debinding method for use in a process for producing a sintered object, by effecting a debinding pre-treatment by heating the injection-molded object in an atmosphere of reduced pressure at a temperature at which the vapor pressure of the component of the organic binder having the highest vapor pressure does not exceed the pressure of the atmosphere, thereby removing the organic binder in the amount of at least about 18 wt %; and effecting a further debinding heat treatment in which the injection-molded object is heated to and maintained at a temperature higher than the temperature in the debinding pre-treatment.

Abstract: There is provided alloy steel powders for the injection molding use manufactured by the atomizing method which are characterized by their substantially spherical particle shape and average particle diameters of 20 microns or less, a compound for the injection molding use which contains the alloy steel powders and one or more organic binders, a process for manufacturing sintered materials in performing injection molding of compound and subsequently debinding the obtained injection molded part followed by sintering the debound part, at least the first stage of the sintering step is performed in reduced pressure atmosphere, and the sintered material having a relative density ratio of 92% or more.

Abstract: An iron base powder mixture for powder metallurgy, comprising an iron based powder and an alloying powder and/or a powder for improving machinability, wherein the alloying powder and/or the powder for improving machinability are adhered to the surface of the ferrous powder by means of a melted-together binder composed of an oil and a metal soap or wax.

Abstract: It is provided a method for the manufacture of a corrosion-resistant sintered alloy steel, which comprises providing a stainless steel powder; adding a binder to said steel powder; molding the mixture; and carrying out the steps of (1) heating the resultant molding to remove the binder therefrom, (2) sintering the thus debound molding under reduced pressure up to 30 Torr, and (3) further sintering at a higher temperature than those of steps (1) and (2) in a non-oxidative atmosphere under substantially atmospheric pressure. It is also provided a corrosion-resistant sintered alloy steel which comprises a stainless steel, said alloy steel having a density ratio of not less than 92%, a maximum diametric of pore present in the structure of not larger than 20 .mu.m, and a content of Cr at the surface of the steel as being sintered which is not less than 80% of a content of Cr in the inside thereof.

Abstract: Disclosed herein is an economical process for the production of a sintered Fe-Co type, Fe-Co-V type or Fe-Co-Cr type magnetic material, which comprises preparing an alloy powder of at least Fe and Co metals of a like powder, kneading it with an organic binder, conducting injection molding and debinding, and then conducting a two-stage sintering treatment consisting of low-temperature sintering and high-temperature sintering. Magnetic materials having a specific composition of the Fe-Co, Fe-Co-V or Fe-Co-Cr type and excellent magnetic properties and a low core loss value are also disclosed.

Abstract: A process is provided for the production of a sintered body. The process includes the following consecutive steps: i) mixing and kneading one or more metal powders and/or one or more alloy powder with a binder into a compound, said metal and alloy powders having an average particle size not greater than 30 .mu.m, ii) injection-molding the compound into a green body; iii) debinding the green body to form a debound body; and iv) subjecting the debound body to a first-stage sintering at 1,050.degree.-1,250.degree. C. in a reduced-pressure atmosphere and then to second-stage sintering at a temperature in a range of 1,100.degree.-400.degree. C. which is higher than that of the first-stage sintering. This process can provide sintered Ti bodies and sintered magnetic bodies of the Fe-Si type, which have a density ratio of at least 95%.

Abstract: Disclosed herein is an economical process for the production of a sintered Fe-Co type, Fe-Co-V type or Fe-Co-Cr type magnetic material, which comprises preparing an alloy powder of at least Fe and Co metals or a like powder, kneading it with an organic binder, conducting injection molding and debinding, and then conducting a two-stage sintering treatment consisting of low-temperature sintering and high-temperature sintering. Magnetic materials having a specific composition of the Fe-Co, Fe-Co-V or Fe-Co-Cr type and excellent magnetic properties and a low core loss value are also disclosed.

Abstract: A starting material for injection molding of a metal powder including from 38 to 46% by volume of an organic binder and the balance of spherical iron powder with an average particle size from 2 to 6 .mu.m, which provides a sintered part having a density ratio of higher than 94%, by conducting injection molding, debinding and sintering in a non-oxidizing atmosphere at a temperature lower than the A.sub.3 transformation point of carbon steel.

Abstract: A process is provided for the production of a sintered body. The process includes the following consecutive steps: (i) mixing and kneading one or more metal powders and/or one or more alloy powder with a binder into a compound, said metal and alloy powders having an average particle size not greater than 30 .mu.m, (ii) injection-molding the compound into a green body; (iii) debinding the green body to form a debound body; and (iv) subjecting the debound body to first-stage sintering at 1,050.degree.-1,250.degree. C. in a reducing or reduced-pressure atmosphere and then to second-stage sintering at a temperature in a range of 1,100.degree.-1,400.degree. C. which is higher than that of the first-stage sintering. This process can provide sintered Ti bodies and sintered magnetic bodies of the Fe-Si type, which have a density ratio of at least 95%.

Abstract: An iron base powder mixture for powder metallurgy, comprising an iron based powder and an alloying powder and/or a powder for improving machinability, wherein the alloying powder and/or the powder for improving machinability are adhered to the surface of the ferrous powder by means of a melted-together binder composed of an oil and a metal soap or wax.

Abstract: A starting material for injection molding of a metal powder including from 38 to 46% by volume of an organic binder and the balance of spherical iron powder with an average particle size from 2 to 6.5 .mu.m and having high density sinterability at low sintering temperature, and a method of producing a sintered parts by conducting injection molding, debinding and sintering using the above-mentioned starting material in a non-oxidizing atmosphere at a temperature lower than the A.sub.3 transformation point.