A wear-resistant armored cutting tool may be provided. The wear-resistant armored cutting tool may include a tool body, a bolster, at least one wear-resistant member, and a cutting tip. The bolster may be fixedly attached to the tool body with an end of a surface of the tool body disposed adjacent the bolster. The at least one wear-resistant member may be fixedly attached to the tool body. The at least one wear-resistant member may be disposed adjacent to the end of the surface of the tool body. The cutting tip may be fixedly attached to the bolster. The bolster, the at least one wear-resistant member, and the cutting tip may each have a material hardness which is greater than that of the tool body.

Provided is a method of manufacturing a high strength steel sheet having excellent workability, including: reheating a steel slab; hot-rolling the reheated steel slab at an Ar3 transformation point or higher; coiling in a temperature range of 400 to 700° C.; primary cooling at a cooling rate of 0.1° C./s or less to room temperature; producing a cold rolled steel sheet at a cold reduction ratio of 40 to 70%; continuously annealing the cold rolled steel sheet in a temperature range of Ac1+30° C. to Ac3−20° C.; secondary cooling at a cooling rate of 10° C./s or less to 630 to 670° C.; third cooling to 400 to 500° C. at a cooling rate of 5° C./s or more in a hydrogen; maintaining for 70 seconds or more; hot-dip galvanizing; and performing a final cooling to Ms or less at a cooling rate of 1° C./s or more.

A hot-rolled (HR) strip steel with high flangeability at ultra-high strength levels with a high total elongation, bendability and toughness values, and a method of manufacturing the hot-rolled steel and use thereof.

A method for manufacturing structural steel components with local reinforcement is provided. The method comprises selecting at least a zone of the component to be reinforced, providing a steel blank and deforming the blank in a press tool to form a product, wherein the blank and/or the product comprises a groove in the zone to be reinforced, the groove comprising an inner surface and an outer surface. The method further comprises depositing a reinforcement material on the inner surface of groove and locally heating the reinforcement material and the groove of the steel blank or product, to mix the melted reinforcement material with the melted portion of the steel blank or product.

A method for producing a steel strip with a multiphase structure by which the production of complex geometries with a high energy-absorption capacity and high resistance to edge cracking is provided achieving a high yield strength or high yield-strength ratio and a high elongation at break, comprising producing a rolled steel strip of particular elements, and first annealing the steel strip at a temperature of between 750° C. and 950° C., and subsequently first cooling of the steel strip to a temperature of between 200° C. and 500° C. at an average cooling rate of 2 K/s to 150 K/s, further cooling of the steel strip to a supercooling temperature below 100° C. at an average cooling rate of 1 K/s to 50 K/s, final annealing of the steel strip with a Hollomon-Jaffe parameter, and final cooling of the steel strip to room temperature at an average cooling rate of 1 K/s to 160 K/s.

This hot-stamping formed article includes a steel sheet, all or part of the steel sheet has a predetermined chemical composition, at a ¼ depth position of a sheet thickness from a surface of the steel sheet, a microstructure contains, by vol %, more than 90.0% of martensite, the average value of Vickers hardness in a region that is 0.3 mm in a sheet thickness direction and 0.6 mm in a direction orthogonal to the sheet thickness direction is 670 or more, the standard deviation of the Vickers hardness in the region is 20 or less, and the tensile strength is 2300 MPa or more.

A steel wire which has excellent cold coiling workability, and which has an excellent fatigue limit when made into a spring is provided. A chemical composition of the steel wire according to the present, embodiment containing, in mass %, C: 0.50 to 0.80%, Si: 1.20 to less than 2.50%, Mn: 0.25 to 1.00%, P: 0.020% or less, S: 0.020% or less, Cr: 0.40 to 1.90%, V: 0.05 to 0.60%, and N: 0.0100% or less, with the balance being Fe and impurities. In the steel wire, a number density of V-based precipitates having a maximum diameter ranging from 2 to 10 nm is 5000 to 80000 pieces/μm.sup.3.

A damper spring which has an excellent fatigue limit is provided. A chemical composition of the damper spring according to the present embodiment contains in mass %, C: 0.50 to 0.80%, Si: 1.20 to less than 2.50%, Mn: 0.25 to 1.00%, P: 0.020% or less, S: 0.020% or less, Cr: 0.40 to 1.90%, V: 0.05 to 0.60%, and N: 0.0100% or less, with the balance being Fe and impurities. In the damper spring, a number density of V-based precipitates having a maximum diameter ranging from 2 to 10 nm is 5000 to 80000 pieces/m3.

A hot-stamping formed body includes a steel sheet and a zinc-plated layer that is provided on the steel sheet. The steel sheet has a predetermined chemical composition, and an area % of martensite is 90% or more in microstructure at a position corresponding to ¼ of a sheet thickness of the steel sheet from a surface of the steel sheet in a sheet thickness direction. The zinc-plated layer includes a F phase and a Fe—Zn solid solution, and a cross-sectional area ratio of voids present in the zinc-plated layer is 15.0% or less.

An object of the present invention is to provide a low thermal expansion cast steel having a high yield strength at room temperature, a high rigidity, and a low coefficient of thermal expansion. The low thermal expansion cast steel of the present invention is obtained by suitably heat treating a cast steel comprising, by mass %, C: 0 to 0.1%, Si: 0 to 0.5%, Mn: 0 to 0.5%, S: 0 to 0.05%, Ni: 29.0 to 34.0%, Co: 0 to 8%, and a balance of Fe and unavoidable impurities so that the 0.2% proof stress becomes 350 MPa or more, the Young's modulus becomes 130 GPa or more, and the average coefficient of thermal expansion at 18 to 28° C. becomes 2.0×10.sup.−6/° C. or less.