Patent classifications
C21D8/12
HOT-ROLLED STEEL SHEET FOR NON-ORIENTED ELECTRICAL STEEL SHEET
A hot-rolled steel sheet for a non-oriented electrical steel sheet containing, in mass %, components of C: 0.0010% to 0.0050%, Si: 1.90% to 3.50%, Al: 0.10% to 3.00%, Mn: 0.05% to 2.00%, P: 0.10% or less, S: 0.005% or less, N: 0.0040% or less and B: 0.0060% or less with a remainder consisting of Fe and impurities, in which, in a sheet width-direction end portion of the hot-rolled steel sheet for a non-oriented electrical steel sheet, a C concentration [atom %] in a crystal grain boundary is 3.0 or more times a P concentration [atom %], and the C concentration [atom %] in the crystal grain boundary of the hot-rolled steel sheet for a non-oriented electrical steel sheet is 3.5 or more times a C concentration in a crystal grain.
Grain-oriented electrical steel sheet with excellent magnetic characteristics
A grain-oriented electrical steel sheet having a metallographic structure after secondary-recrystallized annealing including matrix grains of Goss-oriented secondary recrystallized grains, wherein an existence frequency of Goss-oriented crystal grains having a major diameter of 5 mm or less in the matrix grains is 1.5 grains/cm.sup.2 or more and 8 grains/cm.sup.2 or less, and the magnetic flux density B8 is 1.88 T or more, and wherein deviation angles from a rolling direction of [001] direction of the Goss-oriented crystal grains having the major diameter of 5 mm or less are 7″ or less and 5° or less, in terms of a simple or arithmetic average of α angle and β angle, respectively, wherein the α angle represents an angle formed by a longitudinal direction and a projection of the [001] on a specimen surface, and the β angle represents a tilt of the [001] out of the specimen surface.
GRAIN ORIENTED ELECTRICAL STEEL SHEET
A grain oriented electrical steel sheet includes the texture aligned with Goss orientation. In the grain oriented electrical steel sheet, when (α.sub.1 β.sub.1 γ.sub.1) and (α.sub.2 β.sub.2 γ.sub.2) represent deviation angles of crystal orientations measured at two measurement points which are adjacent on the sheet surface and which have an interval of 1 mm, the boundary condition BA is defined as |γ.sub.2−γ.sub.1|≥0.5°, and the boundary condition BB is defined as [(α.sub.2−α.sub.1).sup.2+(β.sub.2−β.sub.1).sup.2+(γ.sub.2−γ.sub.1).sup.2].sup.1/2≥2.0°, the boundary which satisfies the boundary condition BA and which does not satisfy the boundary condition BB is included.
ELECTRIC RESISTANCE WELDED STEEL PIPE, METHOD FOR PRODUCING THE SAME, LINE PIPE, AND BUILDING STRUCTURE
An electric resistance welded steel pipe includes a base metal zone and an electric resistance welded zone. The base metal zone has a predetermined chemical composition and a microstructure including, by volume, ferrite: more than 30%, and bainite: 10% or more. The total volume fraction of the ferrite and the bainite is 70% or more and 95% or less. The balance being one or two or more phases selected from pearlite, martensite, and austenite. Further, when regions surrounded by boundaries between adjacent crystals having a misorientation of 15° or more are defined as crystal grains, the average size of the crystal grains is less than 7.0 μm, and the volume fraction of crystal grains having a size of 40.0 μm or more is 30% or less. A compressive residual stress generated in the inner and outer surfaces of the steel pipe in the axial direction is 250 MPa or less.
Soft high-silicon steel sheet and manufacturing method thereof
The present invention relates to a soft high-silicon steel sheet, and more particularly, to a soft high-silicon steel sheet which has ductility even if the silicon content thereof is greater than 4%, and can thus be manufactured into a steel sheet having a high silicon content only by means of rolling without an additional siliconizing process. The soft high-silicon steel sheet may include a silicon content greater than 4 wt % and less than or equal to 7 wt % and 1 to 20% of chromium, or may include 5 to 7 wt % of Si+Al and 1 to 20 wt % of chromium.
Annealing separator for oriented electrical steel sheet, oriented electrical steel sheet, and manufacturing method of oriented electrical steel sheet
An annealing separator for an oriented electrical steel sheet includes: a first component including a Mg oxide or a Mg hydroxide; and a second component including one kind among oxides and hydroxides of a metal selected from Al, Ti, Cu, Cr, Ni, Ca, Zn, Na, K, Mo, In, Sb, Ba, Bi, and Mn, or two or more kinds thereof.
Grain-oriented electrical steel sheet and method for manufacturing grain-oriented electrical steel sheet
Provided is an oriented electrical steel sheet including: a forsterite film formed on one side or both sides of an oriented electrical steel sheet substrate; and a ceramic layer formed on an entire or partial region of the forsterite film. Provided is a manufacturing method for an oriented electrical steel sheet including: preparing an oriented electrical steel sheet having a forsterite film formed on one surface or both surfaces thereof; and forming a ceramic layer by spraying ceramic powder on the forsterite film.
Grain-oriented electrical steel sheet and method for manufacturing grain-oriented electrical steel sheet
Provided is an oriented electrical steel sheet including: a forsterite film formed on one side or both sides of an oriented electrical steel sheet substrate; and a ceramic layer formed on an entire or partial region of the forsterite film. Provided is a manufacturing method for an oriented electrical steel sheet including: preparing an oriented electrical steel sheet having a forsterite film formed on one surface or both surfaces thereof; and forming a ceramic layer by spraying ceramic powder on the forsterite film.
Grain-oriented electrical steel sheet and method for manufacturing same and annealing separator
Grain-oriented electrical steel sheet excellent in magnetic properties and excellent in adhesion of a primary coating to the steel sheet is provided. The grain-oriented electrical steel sheet is provided with a base steel sheet having a chemical composition containing C: 0.005% or less, Si: 2.5 to 4.5%, Mn: 0.050 to 1.000%, a total of S and Se: 0.005% or less, sol. Al: 0.005% or less, and N: 0.005% or less and having a balance of Fe and impurities and a primary coating having Mg.sub.2 SiO.sub.4 as a main constituent formed on a surface of the base steel sheet. A peak position of Al emission intensity obtained when conducting elemental analysis by glow discharge spectrometry from a surface of the primary coating in a thickness direction is present in a range of 2.0 to 12.0 μm from a surface of the primary coating to the thickness direction. A sum of perimeters of the Al oxides at the peak position of Al emission intensity is 0.20 to 1.00 μm/μm.sup.2, and a number density of Al oxides is 0.02 to 0.20/μm.sup.2.
GRAIN-ORIENTED ELECTRICAL STEEL SHEET AND METHOD FOR REFINING MAGNETIC DOMAIN THEREOF
A grain-oriented electrical steel sheet according to an exemplary embodiment of the present invention includes: a linear groove formed in one or both surfaces of the electrical steel sheet in a direction intersecting with a rolling direction; and a linear thermal shock portion formed in the one or both surfaces of the electrical steel sheet in a direction intersecting with the rolling direction. An angle between a longitudinal direction of the groove and a longitudinal direction of the thermal shock portion is 1 to 5°.