A method for manufacturing a part of nitrided steel includes a step of nitriding the part. After nitriding, laser shocking is carried out on a surface of the nitrided part.

This disclosure provides a package structure for a semiconductor device, comprising a three-layer film consisting of a first SiO.sub.2 film, a Si.sub.3N.sub.4 film and a second SiO.sub.2 film stacked in this order, wherein the first SiO.sub.2 film is formed by a thermal oxidation process, the Si.sub.3N.sub.4 film is formed by a low pressure chemical vapor deposition process, and the second SiO.sub.2 film is formed by a low temperature atomic layer deposition process. This disclosure also provides a method for preparing the package structure for a semiconductor device.

There is provided a carburized bearing that is excellent in rolling contact fatigue life with a change in structure under a hydrogen-generating environment. In the carburized bearing, a chemical composition of a core portion consists of, in mass %, C: 0.25 to 0.45%, Si: 0.10 to 0.50 %, Mn: 0.40 to 0.70 %, P: 0.015% or less, S: 0.005% or less, Cr: 0.80 to 1.50%, Mo: 0.17 to 0.30%, V: 0.24 to 0.40%. Al: 0.005 to 0.100%, N: 0.0300% or less, O: 0.0015% or less, and the balance being Fe and impurities, and satisfies Formula (1) to Formula (4) described in the present specification. A proportion of a total area of CaO—CaS—MgO—Al.sub.2O.sub.3 composite oxides with respect to a total area of oxides in the carburized leaping is 30.0% or more, and a number density of oxides having an equivalent circle diameter of 20.0 μm or more is 15.0 pieces/mm.sup.2or less.

A workpiece made from a self-passivating metal and having one or more surface regions defining a Beilby layer as a result of a previous metal shaping operation is activated for subsequent low temperature gas hardening by exposing the workpiece to the vapors produced by heating a non-polymeric N/C/H compound.

A crankshaft with improved seizure resistance is provided. A crankshaft having journals 11 and pins 12 includes a compound layer containing iron and nitrogen on its surface, wherein, in the compound layer, for both the journals 11 and pins 12, the porosity area ratio of the thinner one of a region from the surface to a depth of 3.0 μm and a region across the total thickness of the compound layer is not higher than 10.0%, and both the journals 11 and pins 12 have such a surface geometry that the arithmetical mean deviation of the primary profile, Pa, is not larger than 0.090 μm.

The invention relates to a method for producing a screw, having the following steps: (a) rolling a screw wire made of low-alloy carbon steel to produce screw (10) having a thread; (b) heating the entire screw (10) to an austenitizing temperature under a carbon atmosphere and/or nitrogen atmosphere and maintaining the temperature; (c) quenching the entire screw (10) to a bainitizing temperature and maintaining the bainitizing temperature until the screw has a bainitic structure over its cross-section. The invention is characterized in that the screw (10) is subsequently hardened locally at its tip (22), by the tip (22) being heated to an austenitizing temperature and the screw (10) being subsequently quenched to a temperature below the martensite starting temperature (MS).

A grain-oriented electrical steel plate of an exemplary embodiment of the present invention has a groove formed on a surface, wherein a curvature radius RBb at a position where a depth of the groove is maximum is 0.2 μm to 100 μm, and a curvature radius RSb on the groove surface from the position where the depth of the groove is maximum to a quarter-way position of the depth D of the groove is 4 μm to 130 μm.

A method includes additively manufacturing an article in an inert environment, removing the article from the inert environment and placing the article in a non-inert environment, allowing at least a portion the article to oxidize in the non-inert environment to form an oxidized layer on a surface of the article, and removing the oxidized layer (e.g., to smooth the surface of the article). The method can further include relieving stress in the article (e.g., via heating the article after additive manufacturing).

Producing a Ni superalloy component in which the superalloy has a γ phase matrix containing intermetallic γ′ precipitates. Providing a Ni superalloy casting of the component; solutioning the component by heat treating the casting under vacuum and/or in an inert atmosphere at a temperature above the γ′ solvus to homogenize the γ phase; quenching and ageing the solutioned component to grow intermetallic γ′ precipitates in the homogenized γ phase. Before the solutioning step: heat treating the casting to produce a thermally grown oxide on the surface, oxide adherent to supress volatilization of Ni from the surface of the casting during the solutioning heat treatment. Performing the solutioning step under a Ni vapor pressure which is sufficient to supress volatilization of Ni from the surface of the casting during the solutioning heat treatment. During the solutioning heat treatment the component is encapsulated in a container protecting the casting from Si-doped contaminants.

Producing a Ni superalloy component in which the superalloy has a γ phase matrix containing intermetallic γ′ precipitates. Providing a Ni superalloy casting of the component; solutioning the component by heat treating the casting under vacuum and/or in an inert atmosphere at a temperature above the γ′ solvus to homogenize the γ phase; quenching and ageing the solutioned component to grow intermetallic γ′ precipitates in the homogenized γ phase. Before the solutioning step: heat treating the casting to produce a thermally grown oxide on the surface, oxide adherent to supress volatilization of Ni from the surface of the casting during the solutioning heat treatment. Performing the solutioning step under a Ni vapor pressure which is sufficient to supress volatilization of Ni from the surface of the casting during the solutioning heat treatment. During the solutioning heat treatment the component is encapsulated in a container protecting the casting from Si-doped contaminants.