A steel for a tracked undercarriage component is used as a material constituting a track link (9), for example, and contains: not less than 0.39% by mass and not more than 0.45% by mass of carbon, not less than 0.2% by mass and not more than 1.0% by mass of silicon, not less than 0.10% by mass and not more than 0.90% by mass of manganese, not less than 0.002% by mass and not more than 0.005% by mass of sulfur, not less than 0.1% by mass and not more than 3.0% by mass of nickel, not less than 0.70% by mass and not more than 1.50% by mass of chromium, and not less than 0.10% by mass and not more than 0.60% by mass of molybdenum, with the balance made of iron and unavoidable impurities.

A helicoid conveyor screw manufactured from alloy steel and tempered by electromagnetic induction or flame used to convey abrasive granular products in the process of screw rotation under high friction and wear. Its inventive principle is related to the method for obtaining it by alloying steel with the chemical element Boron (B) and heat treating it, which results in greater hardness and durability of the flight.

A metal piece for a motor vehicle has a generally elongated shape according to a longitudinal direction. The piece includes at least one edge extending according to the longitudinal direction, at the intersection of two walls of the piece, and at least one area having a mechanical strength lower than the rest of the body of the piece, wherein the at least one area is formed through local thermal control of the piece. The lower mechanical strength area of the piece undulates along the edge, extending alternatingly along each of the walls forming the edge. A method for making the metal piece is also disclosed.

A control system for heat treatment of a stainless steel part in a furnace having an internal heat treatment chamber with a treatment atmosphere therein arranged in a plurality of zones, the system including at least one analysis apparatus for each one of the plurality of zones, each analysis apparatus in communication with a respective one of the zones for providing a gas to said zone, analyzing an atmosphere of said zone, and sensing a temperature of said zone for determining commencement of nitriding in the treatment atmosphere. A related furnace is also provided.

This disclosure describes new high temperature, radiation-resistant, ferritic-martensitic steel compositions. The new steels generally contain 9.0-12.0 wt. % Cr, 0.001-1.0 wt. % Mn, 0.001-2.0 wt. % Mo, 0.001-2.5 wt. % W, and 0.1-0.3 wt. % C, with the balance being primarily Fe. More specifically, steels having from 10.0-12.0 wt. % Cr are considered particularly advantageous. Small amounts of N, Nb, V, Ta, Ti, Zr, and B may or may not also be present, depending on the particular embodiment. Impurities may be present in any embodiment, in particular impurities of less than 0.01 wt. % S, less than 0.04 wt. % P, less than 0.04 wt. % Cu, less than 0.05 wt. % Co, and less than 0.03 wt. % As are contemplated. Examples of these steels exhibit improved fracture toughness and reduced thermal creep and swelling.

Ferritic stainless steel having a high degree of ductility and a method for manufacturing the ferritic stainless steel are provided. The stainless steel includes, by wt %, C: 0.005% to 0.1%, Si: 0.01% to 2.0%, Mn: 0.01% to 1.5%, P: 0.05% or less, S: 0.005% or less, Cr: 10% to 30%, Ti: 0.005% to 0.5%, Al: 0.01% to 0.15%, N: 0.005% to 0.03%, and the balance of Fe and inevitable impurities, wherein the ferritic stainless steel includes 3.5×10.sup.6 or fewer particles of an independent Ti(CN) precipitate per square millimeter (mm.sup.2) of ferrite matrix.

Steel for a high-strength bolt contains: from 0.50 mass % to 0.65 mass % carbon, from 1.5 mass % to 2.5 mass % silicon, 1.0 mass % or more chromium, 0.4 mass % or less manganese, greater than 1.5 mass % molybdenum, 0.03 mass % or less phosphorus and sulfur combined, and balance iron and inevitable impurities.

A high-strength bolt is formed using steel for a high-strength bolt that contains: from 0.50 mass % to 0.65 mass % carbon, from 1.5 mass % to 2.5 mass % silicon, 1.0 mass % or more chromium, 0.4 mass % or less manganese, greater than 1.5 mass % molybdenum, 0.03 mass % or less phosphorus and sulfur combined, and balance iron and inevitable impurities.

A high surface-pressure resistant component includes a steel having a composition containing, in mass %, 0.17-0.23% of C, 0.80-1.00% of Si, 0.65-1.00% of Mn, 0.030% or less of P, 0.030% or less of S, 0.01-1.00% of Cu, 0.01-3.00% of Ni, and 0.80-1.00% of Cr, with the remainder being Fe and unavoidable impurities, in which the surface layer C concentration of a carburized and quenched layer is 0.70-0.80% in mass %.

To provide an oil-well steel pipe having excellent SSC resistance. The oil-well steel pipe according to the present invention contains, by mass percent, C: 0.15 to 0.35%, Si: 0.1 to 0.75%, Mn: 0.1 to 1.0%, Cr: 0.1 to 1.7%, Mo: 0.1 to 1.2%, Ti: 0.01 to 0.05%, Nb: 0.010 to 0.030%, Al: 0.01 to 0.1%, P: at most 0.03%, S: at most 0.01%, N: at most 0.007%, and O: at most 0.01%, the balance being Fe and impurities. The Ti content and the Nb content in a residue obtained by bromine-methanol extraction satisfy equation (1):
100×[Nb]/([Ti]+[Nb])≦27.5  (1)
where the Ti content (mass %) and the Nb content (mass %) in the residue are substituted for [Ti] and [Nb].

To provide an oil-well steel pipe having excellent SSC resistance. The oil-well steel pipe according to the present invention contains, by mass percent, C: 0.15 to 0.35%, Si: 0.1 to 0.75%, Mn: 0.1 to 1.0%, Cr: 0.1 to 1.7%, Mo: 0.1 to 1.2%, Ti: 0.01 to 0.05%, Nb: 0.010 to 0.030%, Al: 0.01 to 0.1%, P: at most 0.03%, S: at most 0.01%, N: at most 0.007%, and O: at most 0.01%, the balance being Fe and impurities. The Ti content and the Nb content in a residue obtained by bromine-methanol extraction satisfy equation (1):
100×[Nb]/([Ti]+[Nb])≦27.5  (1)
where the Ti content (mass %) and the Nb content (mass %) in the residue are substituted for [Ti] and [Nb].