US 2026/0286482 A1Published application

Non-oriented electrical steel sheet and method for producing same

AssigneeJfe Steel Corporation

InventorsShigehiro MARUYAMA, Tomoyuki OKUBO, Hayato SAITO, Ryuichi SUEHIRO

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Abstract

A non-oriented electrical steel sheet has a component composition including C, Si, Mn, P, S, Al, N, Pb, and Ca, in which the number density of Pb precipitates with a particle size of 10 to 100 nm is 100 particles/mm2 or less, and the number density of Pb—Ca complex precipitates with a particle size of 0.5 to 5.0 μm is 0.1 particles/mm2 to 1000 particles/mm2. A method for producing a non-oriented electrical steel sheet including subjecting a steel slab to a two-stage heating step including first heating at 460° C. to 540° C. for 5 minutes or more, and second heating at 1060° C. to 1140° C. for 20 minutes or more, and finish rolling is performed by setting the entry-side steel sheet temperature in the first pass to 940° C. to 1100° C., and setting rolling reduction in the first pass to 40% or greater.

Claims3

Dependent claims

A non-oriented electrical steel sheet comprising a component composition including, in mass %:

C:
0.005% or less;
Si:
2.5% to 5.0%;
Mn:
0.1% to 3.0%;
P:
0.100% or less;
S:
0.005% or less;
Al:
2.0% or less;
N:
0.005% or less;
Pb:
0.00010% to 0.00200%;
and
Ca:
0.0010% to 0.020%, and further optionally including at least one of Groups A to E of components below:
Group A:
one or more elements selected from the group consisting of Mo:
0.001 to 0.050%, Zn:
0.001 to 0.010%, Ti:
0.001 to 0.010%, Sn:
0.001 to 0.200%, and Sb:
0.001 to 0.200%;
Group B:
one or more elements selected from the group consisting of As:
0.020% or less, Nb:
0.005% or less, W:
0.050% or less, V:
0.050% or less, Ta:
0.0020% or less, and Cu:
0.01 to 1.0%;
Group C:
one or more elements selected from the group consisting of Ni:
0.01 to 1.0% and B:
0.0020% or less;
Group D:
one or more elements selected from the group consisting of Cr:
0.01 to 3.0%, Mg:
0.0001 to 0.005%, and REM:
0.001 to 0.05%;
and
Group E:
one or more elements selected from the group consisting of Co:
0.10% or less, Ge:
0.030% or less, and Ga:
0.030% or less,
with a balance being Fe and unavoidable impurities,
characterized in that:
a number density of Pb precipitates with a particle size of 10 to 100 nm is 100 particles/mm2 or less, and
a number density of Pb—Ca complex precipitates with a particle size of 0.5 to 5.0 μm is 0.1 particles/mm2 to 1000 particles/mm2.

50 more elements

A method for producing a non-oriented electrical steel sheet, comprising:

a hot-rolling step of heating a steel slab with a component composition including, in mass %:
C:
0.005% or less,
Si:
2.5% to 5.0%,
Mn:
0.1% to 3.0%,
P:
0.100% or less,
S:
0.005% or less,
Al:
2.0% or less,
N:
0.005% or less,
Pb:
0.00010% to 0.00200%, and
Ca:
0.0010% to 0.020%, and further optionally including at least one of Groups A to E of components below:
Group A:
one or more elements selected from the group consisting of Mo:
0.001 to 0.050%, Zn:
0.001 to 0.010%, Ti:
0.001 to 0.010%, Sn:
0.001 to 0.200%, and Sb:
0.001 to 0.200%,
Group B:
one or more elements selected from the group consisting of As:
0.020% or less, Nb:
0.005% or less, W:
0.050% or less, V:
0.050% or less, Ta:
0.0020% or less, and Cu:
0.01 to 1.0%,
Group C:
one or more elements selected from the group consisting of Ni:
0.01 to 1.0% and B:
0.0020% or less,
Group D:
one or more elements selected from the group consisting of Cr:
0.01 to 3.0%, Mg:
0.0001 to 0.005%, and REM:
0.001 to 0.05%, and
Group E:
one or more elements selected from the group consisting of Co:
0.10% or less, Ge:
0.030% or less, and Ga:
0.030% or less,
with a balance being Fe and unavoidable impurities, followed by hot-rolling the steel slab to form a hot-rolled steel sheet;
a hot-rolled sheet annealing step of annealing the hot-rolled steel sheet to form a hot-rolled annealed sheet;
a cold-rolling step of subjecting the hot-rolled annealed sheet to cold rolling once or cold rolling two or more times with intermediate annealing interposed between the respective cold-rolling steps to form a cold-rolled steel sheet;
and
a finishing annealing step of subjecting the cold-rolled steel sheet to finishing annealing,
characterized in that:
in the hot-rolling step, the steel slab heating includes a two-stage heating process of a first heating at a temperature of 460° C. to 540° C. for 5 minutes or more and a second heating at a temperature of 1060° C. to 1140° C. for 20 minutes or more, and finish rolling is performed such that, in a first pass, an entry-side steel sheet temperature is between 940° C. and 1100° C. and a rolling reduction is 40% or greater, and
the hot-rolled sheet annealing step is performed at an annealing temperature of 900° C. to 1100° C.

53 more elements

Dependencies are inferred from the claim text.