An amorphous alloy particle is an amorphous alloy particle formed of an iron-based alloy, and the particle contains a grain boundary layer.

Provided are a non-oriented electrical steel sheet with which it is possible to improve steel sheet transferability even when punching is performed successively at high speed, and a method of manufacturing a stacked core using the same. The non-oriented electrical steel sheet contains, by mass percent, Si: 2.0 to 5.0%, Mn: 0.4 to 5.0%, Al≤3.0%, C: 0.0008 to 0.0100%, N≤0.0030%, S≤0.0030%, and Ti≤0.0060%, wherein the product of the contents of Mn and C is 0.004 to 0.05 mass %.sup.2, the yield strength in rolling direction is more than or equal to 600 MPa, and the Young's modulus is more than or equal to 200 GPa. In the method of manufacturing a stacked core, when manufacturing a stacked core using a progressive die, the steel sheet transfer speed V (m/s) satisfies expression (1). V: V.sub.MIN to V.sub.MAX (1) V.sub.MAX=( 1/25)√(t.sup.2×E×YS) (2) V.sub.MIN=( 1/25)√(t.sup.2×120000) (3) t: Steel sheet thickness (mm), E: Young's ratio (GPa), YS: Yield strength (MPa).

A martensitic stainless steel strip capable of achieving higher fatigue strength. This martensitic stainless steel strip has a martensite structure and has a thickness of 1 mm or less, and is characterized in that the compressive residual stress at a surface of the steel strip is 50 MPa or more and the areal ratio of carbides present in the metal structure of the steel strip is 0.5-8.0%. The compressive residual stress at a surface of the steel strip is preferably such that the compressive residual stress in a direction perpendicular to rolling is at least 50 MPa greater than the compressive residual stress in the direction of rolling.

A sheet metal component made of a hot-formed flat steel product including a steel substrate consisting of, in mass. %, C: 0.1-0.4%, Mn: 0.5-3.0%, Si: 0.05-0.5% Cr: 0.005-1.0%, B: 0.0005-0.01% and optionally one or more of V, Ti, Nb, Al, Ni, Cu, Mo, and W, where the contents of the respective optionally present alloy element are V: 0.001-0.2%, Ti: 0.001-0.1%, Nb: 0.001-0.1%, Al: 0.01-0.2%, Ni: 0.01-0.4%, Co: 0.01-0.8% Mo: 0.001-1.0%, W: 0.001-1.0%, and the remainder iron and unavoidable impurities, wherein the unavoidable impurities include contents less than 0.1% P, less than 0.05% S, and less than 0.01% N, and an Al corrosion protection layer applied to the steel substrate, wherein the component is optionally hardened. An adhesive section having an SDR value of 3-30%, determined according to ISO 25178 is provided on the free outer face of the corrosion protection coating for adhering the sheet metal component to another component.

In order to provide an economical method for producing a weapon barrel, in which a considerable plasticisation of the barrel inner wall and thus of the twist profile is avoided when armour-piercing ammunition is shot, in particular in the case of an intense firing sequence, it is proposed not to introduce the twist profile of the weapon barrel into a barrel blank, the material of which has its end strength already as a result of hardening and tempering, but has a lower strength level (approximately 800-1000 MPa). Only once the twist profile has been formed by extrusion or hammering is the steel hardened and tempered to a predefined strength value >1000 MPa, and is the barrel blank that is provided with the twist profile mechanically processed further.

A rolling member is formed of quenched steel having a contact surface. The rolling member includes a superficial part in a region up to a depth of 20 μm from the contact surface. Steel contains greater than or equal to 0.70 mass % and less than or equal to 1.10 mass % of carbon, greater than or equal to 0.15 mass % and less than or equal to 0.35 mass % of silicon, greater than or equal to 0.30 mass % and less than or equal to 0.60 mass % of manganese, greater than or equal to 1.30 mass % and less than or equal to 1.60 mass % of chromium, greater than or equal to 0.01 mass % and less than or equal to 0.50 mass % of molybdenum, and greater than or equal to 0.01 mass % and less than or equal to 0.50 mass % of vanadium, and the remainder of iron and inevitable impurities.

The present disclosure discloses a hot-forging die with the conformal meshy structured cavity surface layer and a preparation method thereof. A large-scale hot-forging die includes a die substrate, and a sandwiched layer, a transition layer and a reinforcement layer are formed on the die substrate in sequence. The reinforcement layer and the transition layer are separated into a plurality of small units by the grooves. All the grooves are interconnected and communicated to form a meshy structure. The transition layer grooves are filled with ordinary soft material; the reinforcement layer grooves are filled with high temperature resistant soft material. The reinforcement layer material and the high temperature resistant soft material of the present disclosure cooperate with each other to obtain a cavity surface layer with properties of both hard and soft, strong and tough, which can fully release the large tensile stress that may occur on the surface of the die cavity during the welding process and under the service conditions of the die, so as to avoid hot cracks during welding process and service process.

The present invention discloses a Fluid End and its manufacturing method. The conventional fluid end manufacturing methods involve machining of all surfaces. This demands more input stock for manufacturing process and a lot of material wastage during machining process. In the conventional processes involving open die forging followed by machining result into only about 34% utilization of material. In the present invention, fluid end component geometry is optimized. Assembly surfaces are machined whereas other or non-assembly surfaces are as-forged condition. The method of invention also results in significant reduction in machining time and chip removal. The present invention also discloses a process of manufacturing using a combination of open die and closed die forging, and machining. It involves the steps of cogging an ingot to form billet for closed die forging using open die forging, forging the billet in closed die using forging equipment, semi-finish/rough/partial machining, heat treatment, drilling and finish machining the component. Most of the non-assembly areas of the fluid end are left in as-forged condition.

The invention relates to a method and to a device for heat treating a metal component. The method comprises at least the following steps: a) heating the component; b) setting a temperature difference between at least one first sub-region and at least one second sub-region of the component; c) at least partially forming and/or cooling the component in a press hardening tool; and d) mechanically post-processing the at least one first sub-region of the component.

A carburized shaft part having a predetermined composition, a C content at a surface layer part of a mass % of 0.60 to 1.00%, at least one hole at an outer circumferential surface, a total volume ratio of martensite and retained austenite of 97% or more at a structure at a position of a 1 mm depth from the outer circumferential surface in an axial direction of the hole and a position of a 20 μm depth from the surface of the hole, a maximum retained austenite volume ratio (R1) of 10.0 to 30.0% at a position of a 1 mm depth from the outer circumferential surface in the axial direction of the hole and a range up to a 200 μm depth from the surface of the hole, and a retained austenite reduction ratio of 20% or more found from R1 and the retained austenite volume ratio (R2) at a position of a 1 mm depth from the outer circumferential surface in the axial direction of the hole and a position of a 20 μm depth from the surface of the hole by the formula (A): Δγ=(R1−R)/R1×100.