C22C38/008

HOT STAMPED BODY

A hot stamped body comprising a steel base material and an Al-Zn-Mg-based plating layer formed on a surface of the steel base material, wherein the plating layer has a predetermined chemical composition, the plating layer comprises an interfacial layer positioned at an interface with the steel base material and containing Fe and Al and a main layer positioned on the interfacial layer, the main layer comprises, by area ratio, 10.0 to 85.0% of an Mg—Zn containing phase and 15.0 to 90.0% of an Fe—Al containing phase, the Mg—Zn containing phase comprises at least one selected from the group consisting of an MgZn phase, Mg.sub.2 Zn.sub.3 phase, and MgZn.sub.2 phase, and the Fe—Al containing phase comprises at least one of an FeAl phase and Fe—Al—Zn phase and an area ratio of the Fe—Al—Zn phase in the main layer is 10.0% or less.

STEEL SHEET

There is provided a steel sheet including a chemical composition consisting of, in mass %: C: 0.03 to 0.25%, Si: 0.1 to 2.0%, Mn: 1.0 to 3.0%, P: 0.200% or less, S: 0.0500% or less, Al: 0.01 to 1.00%, N: 0.0100% or less, and Ti: 0.01 to 0.25%, with the balance: Fe and impurities, and a steel micro-structure containing, in area %: ferrite: 50 to 85%, the balance being one or more kinds selected from martensite, bainite, and retained austenite, and an intensity of γ-fiber is more than 4.0 times in terms of random intensity ratio, and an average KAM value of grains having crystal orientations that form angles within 10° from γ-fiber is 1.30° or less.

Steel sheet for carburizing, and method for manufacturing steel sheet for carburizing

[Object] To provide a steel sheet for carburizing that demonstrates improved ductility, and a method for manufacturing the same. [Solution] A steel sheet consisting of, in mass %, C: more than or equal to 0.02%, and less than 0.30%, Si: more than or equal to 0.005%, and less than 0.5%, Mn: more than or equal to 0.01%, and less than 3.0%, P: less than or equal to 0.1%, S: less than or equal to 0.1%, sol. Al: more than or equal to 0.0002%, and less than or equal to 3.0%, N: less than or equal to 0.2%, Ti: more than or equal to 0.010%, and less than or equal to 0.150%, and the balance: Fe and impurities, in which the number of carbides per 1000 μm.sup.2 is 100 or less, percentage of number of carbides with an aspect ratio of 2.0 or smaller is 10% or larger relative to the total carbides, average equivalent circle diameter of carbide is 5.0 μm or smaller, and average crystal grain size of ferrite is 10 μm or smaller.

Sintered metal friction material
11644076 · 2023-05-09 · ·

The present invention provides a sintered metal friction material that has excellent wear resistance, heat resistance even at high load and has a higher friction coefficient while maintaining a friction coefficient and wear resistance that are hard to decrease, and has a reduced content of copper of less than 5 mass %. There is provided a sintered metal friction material characterized in that the sintered metal friction material comprises a sintered material of a friction material composition, the friction material composition comprises matrix metals and a friction modifier, the matrix metals comprise following 20 to 40 mass % of iron powder, 20 to 40 mass % of nickel powder, 0.5 to 10 mass % of zinc powder, 0.5 to 5 mass, of tin powder, 0.5 to 4 mass % of copper powder and 0.5 to 5 mass % of sintering assist powder.

High-strength reinforcing steel and method for manufacturing same

A method for manufacturing a high-strength steel bar can include the steps of: reheating a steel slab at a temperature ranging from 1000° C. to 1100° C., the steel slab including a certain amount of carbon (C), silicon (Si), manganese (Mn), phosphorus (P), sulfur (S), chromium (Cr), copper (Cu), nickel (Ni), molybdenum (Mo), aluminum (Al), vanadium (V), nitrogen (N), antimony (Sb), tin (Sn), and iron (Fe) and other inevitable impurities, The method can further include finish hot-rolling the reheated steel slab at a temperature of 850° C. to 1000° C., and cooling the hot-rolled steel to a martensite transformation start temperature (Ms (° C.)) through a tempcore process.

Non-oriented electrical steel sheet and method of producing same

Provided is a non-oriented electrical steel sheet that contains substantially no Al and contains large amounts of Si and Mn and has low iron loss, comprising a chemical composition containing C: 0.0050% or less, Si: 2.0% or more and 6.0% or less, Mn: 1.0% or more and 3.0% or less, P: 0.20% or less, S: 0.0050% or less, N: 0.0050% or less, Al: 0.0050% or less, and one or more selected from B: 0.0001% or more and 0.0050% or less, Nb: 0.0001% or more and 0.0050% or less, and V: 0.0005% or more and 0.0500% or less, with a balance consisting of Fe and inevitable impurities, wherein a number density of Si—Mn nitrides with an average diameter of 50 nm or more and 500 nm or less is 1 or less per μm.sup.3.

High-strength steel sheet and production method thereof

A high-strength steel includes a steel structure with: in area fraction, 60.0% to less than 90.0% of ferrite, 0% to less than 5.0% of unrecrystallized ferrite, 2.0% to 25.0% of martensite, 0% to 5.0% of carbide, and 0% to 3.0% of bainite; in volume fraction, more than 7.0% of retained austenite; in a cross-sectional view of 100 μm×100 μm, a value obtained by dividing number of retained austenite that are not adjacent to retained austenite whose crystal orientations are different by a total number of retained austenite being less than 0.80, an average crystal grain size of the ferrite being 6.0 μm or less, an average crystal grain size of the retained austenite being 3.0 μm or less, and a value obtained by dividing, by mass %, an average content of Mn in the retained austenite by an average content of Mn in steel being 1.50 or more.

Ferritic stainless steel sheet and production method thereof, and ferritic stainless member

A ferritic stainless steel sheet is provided that has a chemical composition consisting of, in mass %, C: 0.001 to 0.020%, Si: 0.02 to 1.50%, Mn: 0.02 to 1.50%, P: 0.01 to 0.05%, S: 0.0001 to 0.01%, Cr: 10.0 to 25.0%, Ti: 0.01 to 0.30%, N: 0.001 to 0.030%, and optional elements, with the balance being Fe and unavoidable impurities, wherein: a grain size number is 6 or more; the ferritic stainless steel sheet satisfies the formulas [A+B≥12.0/t], [X+Y≥12.0/(t−0.3)] and [(X+Y)−(A+B)≤5.0] with respect to crystal orientation intensities of a ferrite phase obtained by X-ray diffraction; and the sheet thickness is 1.0 mm or more.

HOT-ROLLED STEEL SHEET

This hot-rolled steel sheet has a predetermined chemical composition, in a microstructure, by area %, ferrite is less than 15.0%, residual austenite is less than 3.0%, L.sub.52/L.sub.7, which is a ratio of a length L.sub.52 of a grain boundary having a crystal orientation difference of 52° to a length L.sub.7 of a grain boundary having a crystal orientation difference of 7° about a <110> direction is 0.10 to 0.18, a standard deviation of a Mn concentration is 0.60 mass % or, less, and a tensile strength is 980 MPa or more.

HIGH-STRENGTH HOT-ROLLED STEEL SHEET AND METHOD FOR MANUFACTURING THE SAME

After low-temperature finish rolling has been performed on a steel material having a certain chemical composition, cooling is performed at an average cooling rate of 10° C./s or higher to a temperature of 500° C., rapid cooling is further performed in a temperature range from a Ms temperature to a temperature of (Ms temperature - 200° C.), coiling is thereafter performed in a low temperature range of 250° C. or lower, and the coiled steel sheet is uncoiled and further subjected to rolling with a certain amount or more of rolling load per unit width and the like. Consequently, it is possible to obtain a high-strength hot-rolled steel sheet having a microstructure including, in terms of area fraction, 95% or more of a martensite phase at a position located at ¼ of the thickness of the steel sheet, in which an average aspect ratio of prior austenite grains is 3.0 or more.