Methods of strengthening surface regions of high-strength transformation induced plasticity (TRIP) steel are provided. The method may comprise shot peening at least one region of an exposed surface of a hot-formed press-hardened component comprising a high-strength steel. Prior to shot peening, the component has a microstructure comprising ≧about 5% by volume retained austenite in a matrix of martensite. The shot peening is conducted at a temperature of <about 150° C. and forms at least one hardened surface region comprising ≦about 2% by volume austenite. The TRIP steel may be zinc-coated and having a surface coating comprising zinc and substantially free of liquid metal embrittlement (LME). Zinc-coated hot-formed press-hardened components, including automotive components, formed from such methods are also provided.

Systems and methods for coldworking metal are described that reduce the axial flow of metal and increase the radial/tangential flow, thereby improving the fatigue life at an aperture. A tool is inserted through an aperture and its travel speed is reduced when in contact with the metal to reduce axial plastic flow. A sensor as part of the motive system moving the mandrel can sense when the tool contacts the metal and reduces the speed of the tool. The tool may move more quickly when not in contact with the metal to reduce working time than when the mandrel is working the metal. The coldworking tool engages the metal at the aperture at a speed of less than the speed which results in the time duration for the mandrel engaging the metal at the aperture for 35 second per inch of metal thickness at the aperture.

A sprocket wheel, which is a machine component configured to slide relative to a bushing while being in contact with the bushing in an outer peripheral surface, includes a base made of a first metal, and an overlay that covers the base so as to constitute the outer peripheral surface. The surface of the overlay constituting the outer peripheral surface has been smoothed. Such a smoothed surface of the overlay makes the sprocket wheel less damaging to the bushing.

The invention relates to a steel plate, the chemical composition of which comprises, the contents being expressed by weight: 0.010%≦C≦0.20%, 0.06%≦Mn≦3%, Si≦1.5%, 0.005%≦Al≦1.5%, S≦0.030%, P≦0.040%, 2.5%≦Ti≦7.2%, (0.45×Ti)−0.35%≦B≦(0.45×Ti)+0.70%, and optionally one or more elements chosen from: Ni≦1%, Mo≦1%, Cr≦3%, Nb≦0.1%, V≦0.1%, the balance of the composition consisting of iron and inevitable impurities resulting from the smelting.

The invention relates to a steel plate, the chemical composition of which comprises, the contents being expressed by weight: 0.010%≦C≦0.20%, 0.06%≦Mn≦3%, Si≦1.5%, 0.005%≦Al≦1.5%, S≦0.030%, P≦0.040%, 2.5%≦Ti≦7.2%, (0.45×Ti)−0.35%≦B≦(0.45×Ti)+0.70%, and optionally one or more elements chosen from: Ni≦1%, Mo≦1%, Cr≦3%, Nb≦0.1%, V≦0.1%, the balance of the composition consisting of iron and inevitable impurities resulting from the smelting.

A conveyor belt configured for a direction of travel, the conveyor belt including a plurality of connecting rods; and a spiral overlay; wherein each of the connecting rods has a flattened oblong cross section. In addition, a method a manufacturing a connector rod for a conveyor, belt includes providing a connector rod having a circular cross section; rolling the connector rod along a longitudinal axis thereof, and thereby producing a flattened oblong cross section.

A flat steel product for hot forming may be produced from a steel substrate that includes a steel comprising 0.1-3% by weight Mn and up to 0.01% by weight B, along with a protective coating that is applied to the steel substrate. The protective coating may be based on Al and may contain up to 20% by weight of other alloy elements. Also disclosed are methods for producing such flat steel products, steel components, and methods for producing steel components. Absorption of hydrogen is minimized during heating necessary for hot forming. This is achieved at least in part through an alloy constituent of 0.1-0.5% by weight of at least one alkaline earth or transition metal in the protective coating, wherein an oxide of the alkaline earth or transition metal is formed on an outer surface of the protective coating during hot forming of the flat steel product.

A method includes, providing a tubular member (10) used for a hollow spring, and applying the compressive residual stress to at least a portion of an inner surface of the steel tube by applying the compressive force to at least a portion of an outer surface of the tubular member (10) from a circumferential direction, and a fatigue life of the tubular member (10) is prolonged by applying the compressive residual stress to the inner surface of the tubular member (10). Applying the force to the outer surface of the tubular member (10) includes pressing the tubular member (10) with a die (1). The die (1) has a pressing surface (1a) shaped such that the compressive force can be applied to at least the portion of the outer surface of the tubular member (10) from the circumferential direction.

A metallic material manufactured by a method including steps of (1) subjecting a semifinished metallic billet having at least one of a nanocrystalline microstructure and an ultrafine-grained microstructure to a rotary incremental forming process to form an intermediate wrought metallic billet and (2) subjecting the intermediate wrought metallic billet to a high rate forming process, wherein the high rate forming process includes a high rate forming process average equivalent strain rate, the high rate forming process average equivalent strain rate being at least about 0.1 s−1.

A metallic material manufactured by a method including steps of (1) subjecting a semifinished metallic billet having at least one of a nanocrystalline microstructure and an ultrafine-grained microstructure to a rotary incremental forming process to form an intermediate wrought metallic billet and (2) subjecting the intermediate wrought metallic billet to a high rate forming process, wherein the high rate forming process includes a high rate forming process average equivalent strain rate, the high rate forming process average equivalent strain rate being at least about 0.1 s−1.