Kobe Steel, Ltd.

Takeo Miyamura

Hiroyuki Mitani

Shigenobu Namba

Hirofumi Hojo

Tomotsuna Kamijo

Hideaki Takauchi

Yoshimasa Muranishi

Zhuyao Chen

Hiromi Oyamada

Provided is a covered electrode for high-Cr ferritic heat-resistant steels with which it is possible to obtain weld metal that has the toughness required for weld parts and has excellent high temperature strength. The covered electrode for high-Cr ferritic heat-resistant steels includes a steel core and a coating agent that coats the core. The covered electrode comprises C, Si, Mn, Ni, Cr, Mo, V, Co, B, Nb, W, N, and Fe each in a predetermined range in the total mass of the covered electrode, contains a slag forming agent, and has a total of the W content and the Co content of 2.8 mass % or more.

Covered electrode for high-Cr ferritic heat-resistant steels

The invention relates to a maraging steel containing C: 0.02% (mass %, hereinafter the same) or less, Si: 0.3% or less, Mn: 0.3% or less, Ni: 7.0 to 15.0%, Cr: 5.0% or less, Co: 8.0 to 12.0%, Mo: 0.1 to 2.0%, Ti: 1.0 to 3.0%, and Sol.Al: 0.01 to 0.2%, where the balance includes Fe and unavoidable impurities of P: 0.01% or less, S: 0.01% or less, N: 0.01% or less, and O: 0.01% or less. The parent phase of the maraging steel includes a martensitic phase. The parent phase contains a martensitic phase obtained by reverse transformation from a martensitic phase to an austenitic phase and then transformation from the austenitic phase, in an area fraction of 25% to 75%.

Maraging steel and method for manufacturing same

Provided is soft magnetic powder used to manufacture a dust core having good mechanical strength and superior formability while iron loss is reduced. The soft magnetic powder for dust cores according to the invention is soft magnetic mixed powder that includes pure iron powder and soft magnetic iron-base alloy powder, wherein the proportion of the soft magnetic iron-base alloy powder in the mixture is 5 to 60 mass %, the ratio of the modes of the particle size distributions of the soft magnetic iron-base alloy powder and the pure iron powder ((the mode of the particle size distribution of the soft magnetic iron-base alloy powder)/(the mode of the particle size distribution of the pure iron powder)) is 0.9 or more and less than 5, and the ratio R/Ris 1.2 or more, where Ris the mass proportion of soft magnetic iron-base alloy powder in mixed powder with a particle size of D50 or more based on the mass fraction, and Ris the mass proportion of soft magnetic iron-base alloy powder in mixed powder with a particle size of less than D50 based on the mass fraction.

Soft magnetic mixed powder

This heat-resistant austenitic stainless steel has a specific composition containing Ce and Zr and has an Hv/Hvratio of 1.20 or higher, where Hvis the average hardness of the area ranging from the surface to a thickness-direction depth of 50 &#x3bc;m and Hvis the average hardness of the thickness-direction central part.

Heat-resistant austenitic stainless steel highly inhibited from exfoliating scale, and stainless steel tube

Disclosed is an iron-based soft magnetic powder obtained by preparing an iron-oxide-based soft magnetic powder through water atomization, and thermally reducing the iron-oxide-based soft magnetic powder. The iron-based soft magnetic powder has an average particle size of 100 &#x3bc;m or more and has an interface density of more than 0 &#x3bc;mand less than or equal to 2.6&#xd7;10&#x3bc;m, where the interface density is determined from a cross-sectional area (&#x3bc;m) and a cross-sectional circumference (&#x3bc;m) of the iron-based soft magnetic powder. The iron-based soft magnetic powder obtained by preparing an iron-oxide-based soft magnetic powder through water atomization and thermally reducing the iron-oxide-based soft magnetic powder, when used for the production of a dust core, can give a dust core having a low coercive force. Also disclosed is a duct core having a low coercive force and exhibiting superior magnetic properties.

Iron-based soft magnetic powder and production method thereof

A powder magnetic core which exhibits a high compact density and a reduced iron loss can be obtained by compacting a soft magnetic powder in which the mass ratio of soft magnetic powder particles that pass through a filter having an opening of 75 &#x3bc;m is 95 mass % or higher relative to the whole amount of the soft magnetic powder and which has a mean strain of less than 0.100%.

Growing community of inventors

Kobe, Japan

Takeo Miyamura