Abstract: A method for removing a ceramic coating from a substrate is presented. The method includes contacting the ceramic coating with a composition including a fluoride source and nitric acid. A method of forming a component having a variation in saturation magnetization is presented. The method includes masking selected portions of a surface of a metallic component using a ceramic coating to form a masked metallic component; selectively diffusing nitrogen into the metallic component by exposing the masked metallic component to a nitrogen-rich atmosphere; and removing the ceramic coating from the surface of the metallic component by contacting the ceramic coating with a composition including the fluoride source and nitric acid.

Abstract: A carburizing process for increasing the hardness of a case region of a steel component. In one form the application includes plating the outer surface of a stainless steel component with nickel prior to carburizing. One component includes a stainless steel object having a hardened case substantially free of continuous phase grain boundary carbides.

Abstract: The invention relates to components made of steel, more particularly outer joint parts and inner joint parts of constant velocity joints, and to a process of heat treating such components made of steel. The heat treatment operation includes the process stages of nitriding, induction surface layer hardening and tempering, which processes follow one another. As a result of the nitriding operation, the joint parts are provided with a surface layer (15) including nitrides and a diffusion layer (18) positioned thereunderneath. The subsequent induction hardening process causes the diffusion layer (18) to be hardened, so that it comprises good supporting characteristics for supporting the surface layer (15) positioned above same.

Abstract: Hardening protection compositions based on substances which form boron glass for partial carburization of metallic components, which contain magnesium-silicon compounds as an additive. These hardening protection compositions can be used very advantageously in processes for the partial carburization of metallic components and in particular are outstandingly suitable for vacuum carburization.

Abstract: A method is disclosed for prevention or stoppage of sulfidation or sulfuric corrosion of metal surfaces in contact with fluids including sulfiding compounds, where the method involves the addition of a compound to the fluid, where the additive has a higher affinity for metal surfaces than sulfur. The additive are group 15 of the periodic table of elements, fluorine-containing compounds, or mixtures or combinations thereof and are added in small quantities generally between about 0.001 ppm and about 20 ppm based on the amount of group 15 element or fluorine in the compound used. A protected metal surface is also disclosed which is coated with a protective coating comprising a group 15 element or fluorine and/or sulfur.

Abstract: A method is disclosed for prevention nitridation or carburization of metal surfaces in contact with a fluid including nitriding agents or carburizing agents where the method involves adding to the fluid an effective amount a sulfur-containing compound and a phosphorus compound, where the amount of phosphorus-containing compound is less than the amount of sulfur-containing compound. The simultaneous addition of both a sulfur compound and a phosphorus compound prevents nitridation and/or carburization and sulfidation of the metal surfaces in contact with fluids containing nitriding and/or carburizing agents significantly increasing the metal's lifetime.

Abstract: A method is disclosed for prevention nitridation or carburization of metal surfaces in contact with a fluid including nitriding agents or carburizing agents where the method involves adding to the fluid an effective amount a sulfur-containing compound and a phosphorus compound, where the amount of phosphorus-containing compound is less than the amount of sulfur-containing compound. The simultaneous addition of both a sulfur compound and a phosphorus compound prevents nitridation and/or carburization and sulfidation of the metal surfaces in contact with fluids containing nitriding and/or carburizing agents significantly increasing the metal's lifetime.

Abstract: A selectively case hardened steel article by low temperature carburization includes a body made of a chromium bearing nickel or ferrous based alloy (for example, stainless steel), a first portion of the body having a first hardness characteristic, and a second portion of the body having a second hardness characteristic; the second portion being less than the entire body and substantially free of carbides. One method for selective case hardening by low temperature carburization includes the steps of applying a carbon blocking mask over surface areas of the article that are not going to be carburized; activating those surface areas that are to be carburized; diffusing carbon into the activated surface areas at a temperature below which carbides readily form; and removing the carbon blocking mask.

Abstract: By forming a Cr playing layer on the surface of a metal and forming a CrN film by nitriding the surface thereof, it is possible to improve the surface hardness, wear resistance, corrosion resistance, etc., of the metal; wherein the nitriding treatment of the Cr plating layer surface is carried out by a method of heating in a nitrided atmosphere, preferably heated in a nitrided atmosphere which includes an ammonia decomposed gas treated in advance with an ammonia decomposition catalyst as a nitrogen source; in addition it is preferable that before the nitriding treatment, the Cr plating layer surface is purified and activated by heating in a halogen compound or a reacting gas which includes halogen.

Abstract: A method for manufacturing precision gears (10) including an initial step of providing a shaped workpiece (30.sub.S) defining a plurality of gear teeth (12) and, furthermore, defining a tooth space surface (68) defined by and between adjacent gear teeth (12). Next, a masking tool (60) is assembled in combination with the shaped workpiece (30.sub.S), which masking tool (60) includes a flexible back-plate (64) and plurality of compliant masking segments (62) bonded to and integrated by the flexible back-plate. Each of the compliant masking segments (62) defines a surface geometry (66) which is substantially complementary to the tooth space surface (68), and adjacent compliant masking segments (62) define an open-ended channel (70) therebetween. As assembled, the compliant masking segments (62) are forcibly urged into superposed engagement with the tooth space surfaces (68). In a subsequent step, a layer of masking material (28) is deposited on exposed surfaces of the shaped workpiece (30.sub.