The present invention relates to a steel for a mold including: on % by mass basis, 0.55%?C?0.70%; 0.30%?Si?0.60%; 0.55%?Mn?1.2%; 5.7%?Cr?6.9%; 1.2%?Mo+W/2?1.6%; 0.55%?V?0.79%; and 0.005%?N?0.1%, with the remainder being Fe and inevitable impurities including, Al?0.020%, Ni?0.20%, S?0.0015%, and Cu?0.10%, and satisfying P1?24 and 4.9?P2?7.3, P1 and P2 being a value obtained based on the following formula (1) and (2), respectively, P1=45?13.6[Si]?7.0([Mo]+[W]/2)?12.9[Ni] (1), P2=7.4[V]+15.8[N]+38.6[Al] (2) in which [M] represents a content of an element M in % by mass basis, and relates to a mold including the steel for a mold.

A direct resistance heating method includes placing a first electrode and a second electrode such that a space is provided between the first electrode and the second electrode and such that each of the first electrode and the second electrode extends across a heating target region of a workpiece, moving at least one of the first electrode and the second electrode with an electric current being applied between the first electrode and the second electrode, and adjusting a time during which the electric current is applied for each segment region of the heating target region, the segment regions being defined by dividing the heating target region and are arranged side by side along a direction in which the at least one of the first electrode and the second electrode is moved.

An agricultural cutting blade has top and bottom surfaces and mounting apertures extending through top and bottom surfaces. A cutting edge support surface (e.g. that may be a flat, pointed or rounded) is formed on the cutting blade body with the cutting edge support extending along a side of the cutting blade body transversely between the top and bottom surfaces. A clad material deposited upon the cutting edge support such as by laser cladding process. The clad material can be built up, that is layered in partial or full overlapping relation to provide at least 2 and often more than 4 layers of clad material at one or more locations. A cutting edge provided by the clad material that may be a ground surface into a laser clad bead.

A process for obtaining a substrate provided with a coating, in which the coating includes a pattern with spatial modulation of at least one property of the coating, includes performing a heat treatment, using a laser radiation, of a continuous coating deposited on the substrate. The heat treatment is such that the substrate is irradiated with the laser radiation focused on the coating in the form of at least one laser line, keeping the coating continuous and without melting of the coating, and a relative displacement of the substrate and of the laser line focused on the coating is imposed in a direction transverse to the longitudinal direction of the laser line, while temporally modulating during this relative displacement the power of the laser line as a function of the speed of relative displacement and of the dimensions of the pattern in the direction of relative displacement.

An inner-flanged bushing for a hydraulic breaker is a tubular shape having an inner flange and is made of a steel containing at least 0.55% and less than 0.70% by mass of carbon, at least 0.15% and less than 0.35% by mass of silicon, at least 0.4% and less than 0.9% by mass of manganese, at least 0.4% and less than 1.3% by mass of chromium, and at least 0.10% and less than 0.55% by mass of molybdenum, with the balance being iron and unavoidable impurities. The bushing includes a base region having a hardness of at least 30 HRC and less than 45 HRC, and a quench hardened layer formed on an inner periphery side of the base region to include an inner peripheral surface of a region including the inner flange, the quench hardened layer having a hardness of at least 55 HRC and less than 63 HRC.

An inner-flanged bushing for a hydraulic breaker is a tubular shape having an inner flange and is made of a steel containing at least 0.55% and less than 0.70% by mass of carbon, at least 0.15% and less than 0.35% by mass of silicon, at least 0.4% and less than 0.9% by mass of manganese, at least 0.4% and less than 1.3% by mass of chromium, and at least 0.10% and less than 0.55% by mass of molybdenum, with the balance being iron and unavoidable impurities. The bushing includes a base region having a hardness of at least 30 HRC and less than 45 HRC, and a quench hardened layer formed on an inner periphery side of the base region to include an inner peripheral surface of a region including the inner flange, the quench hardened layer having a hardness of at least 55 HRC and less than 63 HRC.

A method of manufacturing a steel part including hot stamping followed by trimming, piercing, or flanging, without delayed fracture and without the need for annealing, is provided. The method includes heating a blank formed of a steel material, forming the blank between a pair of dies, and quenching the blank. The temperature drop in select areas of the blank is reduced, which limits the amount of martensite formed in the select areas, but allows martensite to form in other areas. The dies can be formed with modified materials or modified cooling channels to limit the amount of martensite formed in the select areas of the blank. The select areas are softer than the other areas and can be subsequently trimmed, pierced, or flanged without the delayed fractures.

A quench and temper steel alloy is disclosed having the following composition in weight percent. TABLE-US-00001 C 0.2-0.5 Mn 0.1-1.0 Si 0.1-1.2 Cr 9-14.5 Ni 2.0-5.5 Mo 1-2 Cu 0-1.0 Co 1-4 W 0.2 max. V 0.1-1.0 Ti up to 0.5 Nb 0-0.5 Ta 0-0.5 Al 0-0.25 Ce 0-0.01 La 0-0.01
The balance of the alloy is iron and the usual impurities including not more than about 0.01% phosphorus, not more than about 0.010% sulful, and not more than about 0.10% nitrogen. A quenched and tempered steel article made from this alloy is also disclosed. The steel article is characterized by a tensile strength of at least about 290 ksi, a fracture toughness (k.sub.Ic) of at least about 65 ksi, good resistance to general corrosion, and good resistance to pitting corrosion.

A nanocrystalline bainitic steel consisting of, by weight percentage: 0.3% to 0.6% carbon; 9.0% to 20.0% nickel; up to 10% cobalt; 1.0% to 4.5% aluminium; up to 0.5% molybdenum; up to 0.5% manganese; up to 0.5% tungsten; up to 3.0% chromium; and the balance being iron and impurities.

The present invention provides a high strength, high toughness, heat-cracking resistant bainite steel wheel for rail transportation and a manufacturing method thereof. Components are: carbon 0.10-0.40%, silicon 1.00-2.00%, manganese 1.00-2.50%, copper 0.20-1.00%, boron 0.0001-0.035%, nickel 0.10-1.00%, phosphorus0.020%, and sulphur0.020%, where the remaining is iron and unavoidable residual elements, 1.50%Si+Ni3.00%, and 1.50%Mn+Ni+Cu3.00%. Compared with the prior art, in the present invention, by using design of the chemical compositions of steel and wheel manufacturing processes, especially a heat treatment process and technology, a rim of the wheel obtains a carbide-free bainite structure, and a web and a wheel hub obtain a metallographic structure based on granular bainite and a supersaturated ferritic structure. The wheel has comprehensive mechanical properties such as high strength, high toughness, heat-cracking resistant performance and good service performance, thereby improving a service life and comprehensive efficiency of the wheel, bringing specific economic and social benefits.