Method and strip steel knife from a steel strip having a bainite and decarburized surface. The steel strip has a generally rectangular cross-section, and the method includes machining a plurality of beveled surfaces in a region of a longitudinal edge of the steel strip to create at least a cutting surface defining a longitudinal cutting edge; first hardening at least a part of the cutting surface to form a first cutting edge region of the longitudinal cutting edge; smoothing the cutting surface of at least the first cutting edge region toward the longitudinal cutting edge; and at least one further hardening in the first cutting edge region to form a distal cutting edge region of the longitudinal cutting edge within the first cutting edge region having an increased material hardness with respect to the first cutting edge region located outside the distal cutting edge region.

A martensitic steel, consisting of, in % in weight: C: 0.30 to 0.80%, Si: 2.50 to 4.50%, Mn: 1.00 to 2.50%, Al: 0.40 to 1.50%, Cr: 0.1 to 2.00%, V: 0.01 to 0.40%, Ti: 0.005 to 0.35%, and optionally one or more of Nb: less than 0.35%, Zr: less than 0.35%, Ta: less than 0.35%, P: less than 0.25%, S: less than 0.25%, Co: less than 0.50%, Mo: less than 0.90%, W: less than 0.90%, Ni: less than 0.50%, Cu: less than 0.50%, N: less than 0.050%, Ca: less than 0.10%, Mg: less than 0.10%, Ce: less than 0.10%, La: less than 0.10%, B: less than 0.10%, the balance Fe and impurities, and comprising one or more intermetallic phases based on an AlFeMnSi system.

A martensitic steel, consisting of, in % in weight: C: 0.30 to 0.80%, Si: 2.50 to 4.50%, Mn: 1.00 to 2.50%, Al: 0.40 to 1.50%, Cr: 0.1 to 2.00%, V: 0.01 to 0.40%, Ti: 0.005 to 0.35%, and optionally one or more of Nb: less than 0.35%, Zr: less than 0.35%, Ta: less than 0.35%, P: less than 0.25%, S: less than 0.25%, Co: less than 0.50%, Mo: less than 0.90%, W: less than 0.90%, Ni: less than 0.50%, Cu: less than 0.50%, N: less than 0.050%, Ca: less than 0.10%, Mg: less than 0.10%, Ce: less than 0.10%, La: less than 0.10%, B: less than 0.10%, the balance Fe and impurities, and comprising one or more intermetallic phases based on an AlFeMnSi system.

A method for manufacturing an ultra-hard and wear-resistant composite blade, comprising the following steps: carrying out pre-blank-fabricating and pre-matrix-forming treatments on a blade matrix (2) material to form a preformed blank; adding an ultra-hard alloy material in the preformed blank by means of an ultra-high-temperature melting treatment; after cooling, machining and grinding according to the blade specifications to obtain the ultra-hard, wear-resistant and antirust composite blade. The composite blade manufactured using the method has ultra-high hardness, wear resistance and blank antirust performance; moreover, the cutting edge of the nanoscale ultra-hard alloy body is durable and sharp and is not liable to wear.

A method for manufacturing an ultra-hard and wear-resistant composite blade, comprising the following steps: carrying out pre-blank-fabricating and pre-matrix-forming treatments on a blade matrix (2) material to form a preformed blank; adding an ultra-hard alloy material in the preformed blank by means of an ultra-high-temperature melting treatment; after cooling, machining and grinding according to the blade specifications to obtain the ultra-hard, wear-resistant and antirust composite blade. The composite blade manufactured using the method has ultra-high hardness, wear resistance and blank antirust performance; moreover, the cutting edge of the nanoscale ultra-hard alloy body is durable and sharp and is not liable to wear.

Provided is a blade material having high strength. The blade material contains, in % by mass, 0.5 to 0.8% of C, 1.0% or less of Si, 1.0% or less of Mn, 11 to 15% of Cr, and 0.1 to 0.8% of V, the remainder includes Fe and inevitable impurities, and has a thickness of 0.5 mm or less, wherein the structure of the blade material as observed after polishing the surface thereof has ferrites and carbides, the carbides have an average particle diameter of 0.5 m or less, and a proportion of carbides containing V in the carbides is 50% or less in terms of a proportion in an area of a field of view.

Provided is a blade material having high strength. The blade material contains, in % by mass, 0.5 to 0.8% of C, 1.0% or less of Si, 1.0% or less of Mn, 11 to 15% of Cr, and 0.1 to 0.8% of V, the remainder includes Fe and inevitable impurities, and has a thickness of 0.5 mm or less, wherein the structure of the blade material as observed after polishing the surface thereof has ferrites and carbides, the carbides have an average particle diameter of 0.5 m or less, and a proportion of carbides containing V in the carbides is 50% or less in terms of a proportion in an area of a field of view.

Disclosed herein is a method of manufacturing a cutting member that has a first portion for supporting, a second portion for forming a cutting edge, and a third portion connecting the first and second portion; the method includes: providing a first metal material used for forming the first portion; providing a second metal material used for forming the second portion; welding the first and second metal material with high energy density beam to form the third portion at the welding site; performing heat treatment on a cutting member blank obtained after welding. Also disclosed is a cutting member, the first portion of a first metal material; the second portion of a second metal material; after welding, the metallographic structure of the third portion and its nearby metallographic structure are substantially free of holes. The body of the manufactured cutting member has good toughness, the cutting edge has high hardness, and the body and cutting edge are not easily broken and have long service life.

A weld joint with an excellent CTOD property is produced with a weld metal, using a steel plate as a base metal. The steel plate has a chemical composition including C: 0.03% to 0.09%, Si: 0.01% to 0.35%, Mn: 1.3% to 2.0%, P: 0.012% or less, S: 0.0035% or less, Al: 0.01% to 0.06%, Ni: less than 0.3%, Mo: less than 0.10%, Nb: 0.005% to 0.023%, Ti: 0.005% to 0.025%, B: less than 0.0003%, N: 0.002% to 0.005%, Ca: 0.0005% to 0.0050%, and O: 0.0030% or less, with the components additionally satisfying a predetermined relationship. The weld metal has a chemical composition including C: 0.040% to 0.090%, Si: 0.1% to 0.8%, Mn: 1.0% to 2.5%, Al: 0.020% or less, Ni: 0.1% to 1.0%, Mo: 0.05% to 0.50%, Ti: 0.005% to 0.050%, and B: 0.0015% or less, the balance being Fe and incidental impurities.

The present invention provides a steel strip for cutlery, which has a composition containing, in mass %, 0.45 to 0.55% of C, 0.2 to 1.0% of Si, 0.2 to 1.0% of Mn, and 12 to 14% of Cr, and further contains Mo, with the balance made up of Fe and unavoidable impurities, in which Mo is contained in an amount of 2.1 to 2.8%, and the amount of formed M.sub.3C deposited by tempering is decreased to improve bending workability.