Nippon Steel Corporation

Nippon Steel Sumitomo Metal Corporation

Takeru Ichie

Shinichi Matsui

Tesshu Murakawa

Fuminobu Murakami

Yoshiyuki Ushigami

Masahiro Fujikura

Shinichi Kanao

Makoto Atake

Kojiro Hori

Masaru Takahashi

Masahiro Yamamoto

Hiroshi Fujimura

Atsushi Shibayama

Masato Yasuda

Yoshiaki Natori

Hiroyoshi Yashiki

Nobusato Morishige

Kazumi Mizukami

Yoshihiro Arita

Masahide Urago

Daichi Hamada

Daisuke Itabashi

Shinishi Kanao

A hot-rolled steel sheet for a non-oriented electrical steel sheet according to one aspect of the present invention contains, by mass %, C: 0.0050% or less, Si: 0.5% or more and 3.5% or less, Mn: 0.1% or more and 1.5% or less, Al: 0.1% or more and 1.5% or less, Cu: 0.01% or more and 0.10% or less, Sn: 0.01% or more and 0.20% or less, and a remainder including Fe and impurities, in which the hot-rolled steel sheet has a Cu concentration peak value of 0.12% or more in a range from a surface thereof to a depth of 10 μm.

Hot-rolled steel sheet for non-oriented electrical steel sheet, non-oriented electrical steel sheet, and method for manufacturing same

A non oriented electrical steel sheet consists of a silicon steel sheet and an insulation coating. The silicon steel sheet contains Si, Al, and Mn as chemical composition, and an alignment degree to {5 5 7}<7 14 5> orientation in a central area along a thickness direction of the silicon steel sheet is 12 to 35.

Non oriented electrical steel sheet and method for producing thereof

There is provided a non-oriented electrical steel sheet in which, in a cross section of a base material in a sheet thickness direction, the number density Nof precipitates with an equivalent circle diameter of 50 to 500 nm present in a range of 2.0 to 5.0 μm from the surface of the base material in the sheet thickness direction is 0.30 pieces/μmor less, and the relationship between the number density Nand the number density Nof precipitates with an equivalent circle diameter of 50 to 500 nm present in a range from the surface of the base material to 2.0 μm satisfies Formula (1):()/()≤0.5  Formula (1).

Non-oriented electrical steel sheet and method for manufacturing non-oriented electrical steel sheet

A non oriented electrical steel sheet consists of a silicon steel sheet and an insulation coating. The silicon steel sheet includes an internally oxidized layer containing SiOin a surface thereof, an average thickness of the internally oxidized layer is 0.10 to 5.0 μm, and a Vickers hardness in the internally oxidized layer is 1.15 to 1.5 times as compared with a Vickers hardness in a thickness central area.

Non oriented electrical steel sheet

A non-oriented electrical steel sheet includes a silicon steel sheet and an insulation coating. When t is a thickness of the silicon steel sheet and when PDR is defined as (PDR=(maximum&#x2212;minimum)/minimum&#xd7;100) which indicates a ratio concerned with maximum and minimum of number densities of AlN precipitates in three areas which are 1/10t area, &#x2155;t area, and &#xbd;t area from a surface of the silicon steel sheet along a thickness direction, the PDR is 50% or less.

Non-oriented electrical steel sheet

This non-oriented electrical steel sheet including, as a chemical composition, by mass %: C: 0.0100% or less; Si: more than 3.0% and 5.0% or less; Mn: 0.1 to 3.0%; P: 0.20% or less: S: 0.0018% or less: N: 0.0040% or less; Al: 0 to 0.9%; one or more selected from the group consisting of Sn and Sb: 0 to 0.100%; Cr 0 to 5.0%; Ni: 0 to 5.0%; Cu: 0 to 5.0%; Ca: 0 to 0.01%; rare earth elements (REM): 0 to 0.010%; and a remainder including Fe and impurities, in which an area ratio of a crystal structure A composed of crystal grains having a grain size of 100 &#x3bc;m or greater in a cross section parallel to a rolled surface of the non-oriented electrical steel sheet is 1 to 30%, an average grain size of a crystal structure B that is a crystal structure other than the crystal structure A is 25 &#x3bc;m or less, and a Vickers hardness HvA of the crystal structure A and a Vickers hardness HvB of the crystal structure B satisfy HvA/HvB&#x2264;1.000.

A non-oriented electrical steel sheet containing: in mass%, C: 0.005% or less; Si: 0.1% to 2.0%; Mn: 0.05% to 0.6%; P: 0.100% or less; and Al: 0.5% or less, in which 10 pieces/&#x3bc;mor less in number density of non-magnetic precipitate AlN having an average diameter of 10 nm to 200 nm are contained, and an average magnetic flux density B50 in a rolling direction and in a direction perpendicular to rolling is 1.75 T or more. This non-oriented electrical steel sheet can be manufactured by two methods of a method of performing hot rolling annealing at a temperature of 750&#xb0; C. to an Actransformation point and a method of setting a coil winding temperature to 780&#xb0; C. or higher and performing self annealing.

A non-oriented electrical steel sheet containing: in mass %, C: 0.005% or less; Si: 0.1% to 2.0%; Mn: 0.05% to 0.6%; P: 0.100% or less; and Al: 0.5% or less, in which 10 pieces/&#x3bc;mor less in number density of non-magnetic precipitate AlN having an average diameter of 10 nm to 200 nm are contained, and an average magnetic flux density B50 in a rolling direction and in a direction perpendicular to rolling is 1.75 T or more. This non-oriented electrical steel sheet can be manufactured by two methods of a method of performing hot rolling annealing at a temperature of 750&#xb0; C. to an Ac1 transformation point and a method of setting a coil winding temperature to 780&#xb0; C. or higher and performing self annealing.

Non-oriented electrical steel sheet and manufacturing method thereof

A value of a parameter Q represented by 'Q=([Ti]/48+[V]/51+[Zr]/91+[Nb]/93)/([C]/12)' is not less than 0.9 nor more than 1.1, when contents of Ti, V, Zr, Nb, and C (mass %) are represented as [Ti], [V], [Zr], [Nb], and [C] respectively. A matrix of a metal structure is a ferrite phase, and the metal structure does not contain a non-recrystallized structure. An average grain size of ferrite grains constituting the ferrite phase is not less than 30 &#x3bc;m nor more than 200 &#x3bc;m. A precipitate containing at least one selected from the group consisting of Ti, V, Zr, and Nb exists with a density of 1 particle/&#x3bc;mor more in the ferrite grain. An average grain size of the precipitate is not less than 0.002 &#x3bc;m nor more than 0.2 &#x3bc;m.

Non-oriented electrical steel sheet, manufacturing method thereof, laminate for motor iron core, and manufacturing method thereof

When contents of Ti, V, Zr, Nb, and C (mass %) are represented as [Ti], [V], [Zr], [Nb], and [C] respectively, a value of a parameter Q represented by 'Q=([Ti]/48+[V]/51+[Zr]/91+[Nb]/93)/([C]/12)' is not less than 0.9 nor more than 1.1. A matrix of a metal structure is a ferrite phase, and the metal structure does not include a non-recrystallized structure. An average grain size of ferrite grains constituting the ferrite phase is not less than 10 &#x3bc;m nor more than 200 &#x3bc;m. A precipitate containing at least one selected from the group consisting of Ti, V, Zr, and Nb exists with a density of 10 &#x3bc;mor more in the ferrite grain. An average grain size of the precipitate is not less than 0.002 &#x3bc;m nor more than 0.2 &#x3bc;m.

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Tokyo, Japan

Takeru Ichie