Abstract: A cold-rolled steel sheet satisfies that an average pole density of an orientation group of {100}<011> to {223}<110> is 1.0 to 5.0, a pole density of a crystal orientation {332}<113> is 1.0 to 4.0, a Lankford-value rC in a direction perpendicular to a rolling direction is 0.70 to 1.50, and a Lankford-value r30 in a direction making an angle of 30° with the rolling direction is 0.70 to 1.50. Moreover, the cold-rolled steel sheet includes, as a metallographic structure, by area %, a ferrite and a bainite of 30% to 99% in total and a martensite of 1% to 70%.

Abstract: This high-strength cold-rolled steel sheet having excellent uniform elongation and hole expandability contains, C: 0.01 to 0.4%; Si: 0.001 to 2.5%; Mn: 0.001 to 4.0%; P: 0.001 to 0.15%; S: 0.0005 to 0.03%; Al: 0.001 to 2.0%; N: 0.0005 to 0.01%; and O: 0.0005 to 0.01%; in which Si+Al is limited to less than 1.0%, and a balance being composed of iron and inevitable impurities, in which at a sheet thickness center portion, an average value of pole densities of the {100}<011> to {223}<110> orientation group is 5.0 or less, and a pole density of the {332}<113> crystal orientation is 4.0 or less, a metal structure contains 5 to 80% of ferrite, 5 to 80% of bainite, and 1% or less of martensite in terms of an area ratio and the total of martensite, pearlite, and retained austenite is 5% or less, and an r value (rC) in a direction perpendicular to a rolling direction is 0.70 or more and an r value (r30) in a direction 30° from the rolling direction is 1.10 or less.

Abstract: In a hot-rolled steel sheet, an average pole density of an orientation group of {100}<011> to {223}<110>, which is represented by an arithmetic average of pole density of each orientation of {100}<011>, {116}<110>, {114}<110>, {112}<110>, and {223}<110> in a center portion of a sheet thickness which is a range of the sheet thickness of ? to ? from a surface of the steel sheet, is 1.0 or more and 4.0 or less, the pole density of a crystal orientation of {332}<113> is 1.0 or more and 4.8 or less, an average grain size in a center in the sheet thickness is 10 ?M or less, and a microstructure includes, by a structural fraction, pearlite more than 6% and ferrite in the balance.

Abstract: This high-strength cold-rolled steel sheet contains, in mass %, C: 0.02% to 0.20%; Si: 0.001% to 2.5%; Mn: 0.01% to 4.0%; P: 0.001% to 0.15%; S: 0.0005% to 0.03%; Al: 0.001% to 2.0%; N: 0.0005% to 0.01%; and O: 0.0005% to 0.01%; in which Si+Al is limited to less than 1.0%, and a balance being composed of iron and inevitable impurities, in which an area ratio of bainite in a metal structure is 95% or more, at a sheet thickness center portion being a range of ? to ? in sheet thickness from the surface of the steel sheet, an average value of pole densities of the {100}<011> to {223}<110> orientation group is 4.0 or less, and a pole density of the {332}<113> crystal orientation is 5.0 or less, and a mean volume diameter of crystal grains in the metal structure is 7 ?m or less.

Abstract: Disclosed is a hot-rolled steel sheet including, by mass %, C:0.02% to 0.5% of C, and the sum of the content of Si and the content of Al is 1.0% to 4.0%. An average pole density of an orientation group from {100}<011> to {223}<110> is 1.0 to 6.5, and a pole density of a crystal orientation {332}<113> is 1.0 to 5.0. A microstructure includes, by of an area ratio, 2% to 30% of retained austenite, 20% to 50% of ferrite, and 10% to 60% of bainite. rC that is a Lankford value in a direction orthogonal to a rolling direction is 0.70 to 1.10, and r30 that is a Lankford value in a direction forming an angle of 30° with the rolling direction is 0.70 to 1.10.

Abstract: In a hot-rolled steel sheet, an average pole density of an orientation group {100}<011> to {223}<110>, which is represented by an arithmetic mean of pole densities of orientations {100}<011>, {116}<110>, {114}<110>, {112}<110>, and {223}<110> is 1.0 to 4.0 and a pole density of a crystal orientation {332}<113> is 1.0 to 4.8, in a thickness center portion which is a thickness range of ? to ? from the surface of the steel sheet; an average grain size in the thickness center portion is less than or equal to 10 ?m and a grain size of cementite precipitating in a grain boundary of the steel sheet is less than or equal to 2 ?m; and an average grain size of precipitates containing TiC in grains is less than or equal to 3 nm and a number density per unit volume is greater than or equal to 1×1016 grains/cm3.

Abstract: This is a cold-rolled steel sheet includes, by mass %, C: 0.02% to 0.4%, Si: 0.001% to 2.5%, Mn: 0.001% to 4.0%, and Al: 0.001% to 2.0%. The sum of the Si content and the Al content is 1.0% to 4.5%. An average pole density of an orientation group from {100}<011> to {223}<110> is 1.0 to 6.5, and a pole density of a crystal orientation {332}<113> is 1.0 to 5.0. A microstructure includes, by an area ratio %, 5% to 80% of ferrite, 5% to 80% of bainite, and 2% to 30% of retained austenite. In the microstructure, by an area ratio %, martensite is limited to 20% or less, pearlite is limited to 10% or less, and tempered martensite is limited to 60% or less.

Abstract: The present invention provides a bainite-containing-type high-strength hot-rolled steel sheet. The steel sheet, containing C: greater than 0.07 to 0.2%, Si: 0.001 to 2.5%, Mn: 0.01 to 4%, P: 0.15% or less, S: 0.03% or less, N: 0.01% or less, Al: 0.001 to 2% and a balance being composed of Fe and impurities, has an average value of pole densities of the {100}<011> to {223}<110> orientation group at a sheet thickness center portion being a range of ? to ? in sheet thickness from the surface of the steel sheet is 4.0 or less, and a pole density of the {332}<113> crystal orientation is 4.8 or less, an average crystal grain diameter is 10 ?m or less and vTrs is ?20° C. or lower, and a microstructure is composed of 35% or less in a structural fraction of pro-eutectoid ferrite and a balance of a low-temperature transformation generating phase.

Abstract: In a hot-rolled sheet, an average value of pole densities of an orientation group {100}<011> to {223}<110>, which is represented by an arithmetic mean of pole densities of orientations {100}<011>, {116}<110>, {114}<110>, {112}<110>, and {223}<110> in a thickness center portion of a thickness range of ? to ? from a surface of the steel sheet, is 1.0 to 6.5 and a pole density of a crystal orientation {332}<113> is 1.0 to 5.0; and a Lankford value rC in a direction perpendicular to a rolling direction is 0.70 to 1.10 and a Lankford value r30 in a direction that forms 30° with respect to the rolling direction is 0.70 to 1.10.

Abstract: A hot-dip galvanized steel sheet includes a steel sheet and a hot-dip galvanized layer arranged on the steel sheet, in which the Si content and the Al content by mass % of components of the steel sheet satisfy a relationship 0.5<Si+Al<1.0, and a metallographic structure of the steel sheet satisfies a relationship of {(n2)2/3×d2}/{(n1)2/3×d1}×ln(H2/H1)<0.3 when the n1 is the number of a MnS of a surface portion of the steel sheet, the d1 ?m is an average equivalent circle diameter of the MnS in the surface portion of the steel sheet, the H1 GPa is a hardness of a martensite of the surface portion of the steel sheet, the n2 is the number of the MnS of a center portion of the steel sheet, the d2 ?m is an average equivalent circle diameter of the MnS in the center portion of the steel sheet, and the H2 GPa is the hardness of the martensite of the center portion of the steel sheet.

Abstract: A hot-rolled steel sheet has an average value of the X-ray random intensity ratio of a {100} <011> to {223} <110> orientation group at least in a sheet thickness central portion that is in a sheet thickness range of ? to ? from a steel sheet surface of 1.0 to 6.0, an X-ray random intensity ratio of a {332} <113> crystal orientation of 1.0 to 5.0, rC which is an r value in a direction perpendicular to a rolling direction of 0.70 to 1.10, and r30 which is an r value in a direction that forms an angle of 30° with respect to the rolling direction of 0.70 to 1.10.

Abstract: A high-strength cold-rolled steel sheet includes, by mass %, C: 0.10% to 0.40%, Mn: 0.5% to 4.0%, Si: 0.005% to 2.5%, Al: 0.005% to 2.5%, Cr: 0% to 1.0%, and a balance of iron and inevitable impurities, in which an amount of P is limited to 0.05% or less, an amount of S is limited to 0.02% or less, an amount of N is limited to 0.006% or less, the microstructure includes 2% to 30% of retained austenite by area percentage, martensite is limited to 20% or less by area percentage in the microstructure, an average particle size of cementite is 0.01 ?m to 1 ?m, and 30% to 100% of the cementite has an aspect ratio of 1 to 3.

Abstract: A floating type brake disc is provided which is capable of limiting the heat escape from a rotor to a hub to the extent possible and which can be made smaller in weight. In a plurality of circumferential positions of the hub, there are formed pin-receiving portions in a manner to enclose a connecting pin from three directions of a radially inward, one of circumferentially both sides and a radially outward of the brake disc. A tongue-shaped pin-receiving portion is formed on each of a plurality of inner circumferential positions of the rotor 1 so as to be elongated radially inward to pinch the connecting pin between the tongue-shaped pin-receiving portion and the pin-receiving portion that is formed in the hub.

Abstract: With regard to an Al content (%) and a Si content (%), a relation of a formula (A) is established, and an average value Yave defined by a formula (B) regarding hardnesses measured at 100 points or more with a nanoindenter is equal to or more than 40. 0.3?0.7×[Si]+[Al]?1.5??(A) Yave=?(180×(Xi?3)?2/n)??(B) ([Al] indicates the Al content (%), [Si] indicates the Si content (%), n indicates a total number of the measuring points of the hardnesses, and Xi indicates the hardness (GPa) at the i-th measuring point (i is a natural number equal to or less than n).

Abstract: This high strength hot-rolled steel sheet includes: in terms of percent by mass, C: 0.05 to 0.12%; Si: 0.8 to 1.2%; Mn: 1.6 to 2.2%; Al: 0.30 to 0.6%; P: 0.05% or less; S: 0.005% or less; and N: 0.01% or less, with the remainder being Fe and unavoidable impurities, wherein a microstructure includes specific ranges (in area %) of ferrite phases as well as martensite phases, and a maximum concentration of Al detected by a glow discharge emission spectroscopic analysis is in a range of 0.75 mass % or less in a region from a surface of the steel sheet to a thickness of 500 nm after being acid-pickled.

Abstract: The high-strength steel sheet includes, by mass %: C: 0.01% to 0.10%; Si: 0.15% or less; Mn: 0.80% to 1.80%; P: 0.10% or less; S: 0.015% or less; Al: 0.10% to 0.80%; Cr: 0.01% to 1.50%; N: 0.0100% or less; and a balance consisting of iron and inevitable impurities, in which a metallic structure is composed of ferrite and a hard second phase, the area fraction of the ferrite is 80% or more, the area fraction of the hard second phase is 1% to 20%, the fraction of unrecrystallized ferrite in the ferrite is less than 10%, the ferrite grain sizes are 5 ?m to 20 ?m, and the fraction of the ferrite crystal grains having an aspect ratio of 1.2 or less in the entire ferrite crystal grains is 60% or more.

Abstract: A high strength steel sheet excellent in formability which has a chemical composition in mass %: C: 0.03 to 0.20%, Si: 0.005 to 0.3%, Mn: 1.0 to 3.1%, P: 0.001 to 0.06%, S: 0.001 to 0.01%, N: 0.0005 to 0.01%, Al: 0.2 to 1.2%, Mo?0.5%, and the balance: Fe and inevitable impurities, with the proviso that the values of mass % for Si and Al satisfy the following formula (1): (0.0012×[objective value of TS]?0.29?[Si])/2.45<Al<1.5?3×[Si]??(1) wherein [objective value of TS] represents a design strength value for the steel sheet in an Mpa unit, and has a metal structure containing ferrite and martensite. The above high strength steel sheet is also excellent in formability and the capability of being chemically treated and that of being hot-dip zinc sheeted.

Abstract: The present invention provides: a high-strength high-ductility hot-dip galvanized steel sheet and hot-dip galvannealed steel sheet having high fatigue resistance and corrosion resistance; a high-strength hot-dip galvanized steel sheet excellent in ductility, which improves non-plating defects and plating adhesion after severe deformation, and a method of producing the same; a high-strength and high-ductility hot-dip galvanized steel sheet having high fatigue resistance and corrosion resistance; a high-strength hot-dip galvanized steel sheet and hot-dip galvannealed steel sheet having superior appearance and workability, which suppresses the generation of non-plating defects, and a method of producing the same; and a high-strength hot-dip galvannealed steel sheet and a high-strength hot-dip galvanized steel sheet, which suppress non-plating defects and surface defects and have both corrosion resistance, in particular corrosion resistance in an environment containing chlorine ion, and high ductility, and a meth

Abstract: Provided is a galvanized steel sheet having a tensile strength of 770 MPa or more including a steel sheet portion, and a plated layer formed on the surface of the steel sheet portion, in which the plated layer is a galvanized plated layer or an galvannealed plated layer, the steel sheet portion has a soft layer that directly adjoins the interface with the plated layer and an inside layer that is other than the soft layer, the thickness D of soft layer is 0.001% to 5% of thickness t of the steel sheet portion, and, when the hardness of the soft layer measured by nano-indentation method is indicated by H1, and the representative hardness of the steel sheet portion measured by the nano-indentation method is indicated by Ha in cross section that goes along the thickness direction of the steel sheet portion, H1 is 5% to 75% of Ha.

Abstract: This high-strength steel sheet includes: in terms of percent by mass, 0.03 to 0.10% of C; 0.01 to 1.5% of Si; 1.0 to 2.5% of Mn; 0.1% or less of P; 0.02% or less of S; 0.01 to 1.2% of Al; 0.06 to 0.15% of Ti; and 0.01% or less of N; and contains as the balance, iron and inevitable impurities, wherein a tensile strength is in a range of 590 MPa or more, and a ratio between the tensile strength and a yield strength is in a range of 0.80 or more, a microstructure includes bainite at an area ratio of 40% or more and the balance being either one or both of ferrite and martensite, a density of Ti(C,N) precipitates having sizes of 10 nm or smaller is in a range of 1010 precipitates/mm3 or more, and a ratio (Hvs/Hvc) of a hardness (Hvs) at a depth of 10 ?m from a surface to a hardness (Hvc) at a center of a sheet thickness is in a range of 0.85 or more.