Dispersoids 7xxx aluminum alloy products with enhanced fatigue crack growth deviation and Environmentally Assisted Cracking (EAC) resistance are disclosed. The 7xxx aluminum alloy comprises 1 to 3 wt. % Cu, 1.2 to 3 wt. % Mg, 4 to 8.5 wt. % Zn, up to 0.3 wt. % Mn, up to 0.15 wt. % Zr, up to 0.3 wt. % Cr dispersoid elements, incidental elements, and the balance Al. In one embodiment, the alloy includes Zr+Cr+Mn in the range of 0.2 to 0.8 wt. %. In another embodiment, the alloy includes Zr+Mn in the range of 0.07 to 0.7 wt. %. This alloy can be fabricated to plate, extrusion, or forging products, and is especially suitable for aerospace structural components. The products have enhanced EAC resistance and fatigue crack growth deviation resistance. Meanwhile, the products have an excellent combination of strength, fracture toughness, ductility at different orientations, and Stress Crack Corrosion (SCC), and exfoliation corrosion resistance suitable for aerospace application.

A method of manufacturing a high strength steel sheet having excellent formability suitable for the material of an automotive part has a tensile strength (TS) of 980 MPa or more and total elongation (EL) is 25% or more. A steel slab has a chemical composition containing C: 0.03% to 0.35%, Si: 0.5% to 3.0%, Mn: 3.5% to 10.0%, P: 0.100% or less, S: 0.02% or less, and the remainder includes Fe and incidental impurities on a percent by mass basis is hot-rolled, a heat treatment is performed, in which an achieved temperature of Ac1 to Ac1+100 C. is held for 3 minutes or more, subsequently, cold rolling is performed at a rolling reduction of 20% or more and, annealing is performed, in which an achieved temperature of Ac130 C. to Ac1+100 C. is held for 1 minute or more.

A high-strength galvanized steel sheet includes a base steel sheet and a galvanized layer on a surface thereof. The base steel sheet has a predetermined chemical composition and a microstructure in which an area fraction of martensite is 30% or less, an area fraction of pearlite is 1% or less, a total area fraction of tempered martensite and carbide-containing bainite is 30% or more and 99% or less, an area fraction of retained austenite is 1% to 20%, and a total area fraction of ferrite and non-carbide-containing bainite is 45% or less in the steel sheet microstructure in a predetermined region and in which an area fraction of retained austenite grains having two or more crystal orientations is 40% or less in all the retained austenite grains in a predetermined region.

A device for continuously applying a transverse tension in an annealing process of an ultra-thin strip, including an unfolding and receiving mechanism for unwinding and winding the strip and an orthopedic mechanism for correcting the strip including an annealing furnace, and two orthopedic assemblies fixedly arranged inside the annealing furnace; the two orthopedic assemblies are symmetrically arranged on both sides of the strip, are parallel to an advancing direction of the strip and correspond to side edges of the strip, and include annular guide rails; each annular guide rail is fixedly connected with the annealing furnace and is slidably connected with an orthopedic part; the orthopedic part corresponds to each side edge of the strip, and each annular guide rail is internally provided with a driving part; the driving part is in transmission connection with the orthopedic part, and the orthopedic part is communicated with an air source part.

Provided is a hot stamped body comprising a steel base material, an Al-plating layer formed on at least one surface of the steel base material, a coating formed on the Al-plating layer and containing ZnO particles and CeO.sub.2 particles having an average particle size smaller than an average particle size of the ZnO particles, and a Zn- and Al-containing complex oxide layer formed between the Al-plating layer and the coating. Further, provided is a method for producing a hot stamped body comprising forming an Al-plating layer on at least one side of a steel sheet, coating a surface of the Al-plating layer with an aqueous solution containing ZnO particles and CeO.sub.2 particles, then heating it to form a coating containing ZnO particles and CeO.sub.2 particles on the Al-plating layer, and hot pressing the steel sheet. Further, provided is an Al-plated steel sheet comprising a steel base material, an Al-plating layer formed on at least one surface of the steel base material, and a coating formed on the Al-plating layer and containing ZnO particles and CeO.sub.2 particles having an average particle size smaller than an average particle size of the ZnO particles.

High strength plated steel sheet having high hydrogen embrittlement resistance, that is, alloyed hot dip galvannealed steel sheet including steel sheet containing C: 0.05 to 0.40%, Si: 0.2 to 3.0%, Mn: 0.1 to 5.0%, and sol. Al: 0.4 to 1.50% and a alloyed hot dip galvannealed layer deposited on at least one surface of the steel sheet to 10 to 100 g/m.sup.2 and containing Fe: 5.0 to 15.0% and Al: 0.01 to 1.0%, having an internal oxidation layer including grain boundary oxides in a surface layer of the steel sheet, when examining a cross-section of a surface layer of the steel sheet, a Ratio A of the length of the grain boundary oxides projected an interface of the steel sheet and the alloyed hot dip galvannealed layer to the length of interface is 50% or more and 100% or less, and a surface depleted layer with a steel composition not including the grain boundary oxides which satisfies, by mass %, Si0.6% and Al0.05% is included at a depth of of the average depth of the internal oxidation layer.

Disclosed is a 980 MPa grade cold-roll steel sheets with high hole expansion rate and higher percentage elongation, and manufacturing method thereof. The mass percents of chemical components in the steel sheet are: C: 0.08%-0.12%, Si: 0.1%-1.0%, Mn: 1.9%-2.6%, Al: 0.01%-0.05%, Cr: 0.1-0.55%, Mo: 0.1-0.5%, Ti: 0.01-0.1%, the rest being Fe and other inevitable impurities. The steel plate has a yield strength >600 MPa, a tensile strength >980 MPa, a percentage elongation >11%, a hole expansion rate 45%, and a tensile strength up to 980 MPa grade; the microscopic structure is ferrite plus bainite plus martensite, with the volume fraction content of ferrite >10%, the volume fraction content of bainite >30%, and the volume fraction content of martensite >15%; the microscopic structure further comprises nanoscale precipitates in uniform dispersion distribution, the average size of precipitates being less than 20 nm.

A high strength steel sheet having 1180 MPa or higher tensile strength and a method for manufacturing the same are disclosed. The high strength steel sheet has a specific chemical composition and is such that in a region at sheet thickness, the area fraction of martensite is 80% or more, the volume fraction of retained austenite is 3% or more and 15% or less, the area fraction of the total of ferrite and bainitic ferrite is 10% or less, the average grain size of prior austenite is 20 m or less, and the average of the proportions of packets having the largest area in prior austenite grains is 70% by area or less of the prior austenite grain.

This disclosure provides a method of producing an alloy strip laminate including applying an external force directly to an alloy strip of a first laminate member having an adhesive layer and the alloy strip, to form a crack in the alloy strip and prepare a first laminate including the adhesive layer and the cracked alloy strip, applying an external force directly to an alloy strip of a second laminate member having an adhesive layer and the alloy strip, to form a crack in the alloy strip and prepare at least one second laminate including the adhesive layer and the cracked alloy strip, and laminating the at least one second laminate on the first laminate to prepare an alloy strip laminate in which the adhesive layer, and the alloy strip with the crack formed are alternately layered; and a production apparatus for an alloy strip laminate.

A steel sheet and a member with a TS of 1180 MPa or more, and a method for producing them, are disclosed. A base steel sheet has a specified chemical composition. In a steel microstructure of the base steel sheet, bainitic ferrite, tempered martensite, retained austenite, and fresh martensite are in specified ranges. The concentration of carbon in retained austenite and the density of carbides in tempered martensite are in specified ranges. The amount of diffusible hydrogen is 0.50 ppm by mass or less. A V-VDA bending test is performed to the maximum load point. In an L cross section, a crack has a length of 400 m or less. In a specified region of VDA bending, a change in the grain size of bainitic ferrite in the thickness direction due to processing is 5.0 or less.