A tube assembly includes at least first and second tubes configured for coupling at respective ends. The first and second tubes each include a base material, and a weld interface at the respective end. The weld interface is proximate to an inner diameter and an outer diameter of the first and second tubes, and includes a weld interface segment extending therebetween. A work hardened weld assembly couples the base material of each of the first and second tubes. The work hardened weld assembly includes a weld fusion zone between the weld interfaces of the first and second tubes and the weld interface segments of the first and second tubes. The weld fusion zone is work hardened and at least the weld interface segments of the first and second tubes are work hardened between the work hardened weld fusion zone and the base material of the first and second tubes.

A compressive torsion forming device for processing a processing material using a first die and a second die facing each other includes a sliding portion that includes a first hydraulic chamber, and slides in accordance with a change in internal pressure of the first hydraulic chamber so as to move the first die in a direction of an axis; a rotating table provided with the second die and rotatable about the axis; a table support portion provided opposite to the second die with the rotating table interposed therebetween in the direction of the axis; and a rotational bearing that rotatably supports the rotating table with respect to the table support portion, and receives a force acting on the rotating table in a direction from the second die toward the rotating table.

A motor vehicle tire is reinforced by at least one carbon steel band that has a very low carbon content and high strength in the work-hardened state The carbon steel comprises (% by weight) between 0.05% and 0.4% of carbon, between 0.5% and 4% of manganese, between 0.1% and 2.5% of silicon, optionally (i) less than 1.5% of aluminium, (ii) less than 0.5% of each of the metals boron, chromium, cobalt, copper, molybdenum, nickel, niobium, titanium, tungsten, vanadium, and zirconium, and (iii) less than 0.05% of each of the elements phosphorus, sulfur, nitrogen, or rare earth, and the rest is made up of iron and inevitable impurities resulting from the smelting. The microstructure of the work-hardened carbon steel is mainly martensitic or ferritic-martensitic. The strength, denoted Rm, of the strip is greater than 1200 MPa and its elongation at break, denoted At, is between 1% and 5%.

Disclosed are a non-normalized steel composition which includes carbon (C), silicon (Si), manganese (Mn), sulfur (S), vanadium (V), titanium (Ti), nitrogen (N), and iron (Fe), and a method of manufacturing the connecting rod for improving yield strength, fatigue strength, and the like of the connecting rod. The non-normalized steel composition includes carbon (C) in an amount of about 0.30 to 0.55 weight %, silicon (Si) in an amount of about 0.80 to 1.20 weight %, manganese (Mn) in an amount of about 0.80 to 1.20 weight %, sulfur (S) in an amount of about 0.06 to 0.10 weight %, vanadium (V) in an amount of about 0.20 to 0.35 weight %, titanium (Ti) in an amount of about 0.01 to 0.20 weight %, nitrogen (N) in an amount of about 0.005 to 0.02 weight %, and the remainder of iron (Fe), and inevitable impurities, based on a total weight of the composition.

The present invention relates to a torsional severe plastic deformation method for a metal bar to which surface polishing is applied to the metal bar to improve the mechanical properties of the metal bar. According to an embodiment of the present invention, there is provided a torsional severe plastic deformation method for a metal bar, which includes: applying torsion to a metal bar; and removing a surface defect on the surface of the metal bar, the surface defect being caused by the applying of torsion, wherein the removing of the surface defect is carried out in a continuous manner in which the removing of the surface defect is performed together with the applying of torsion or in a discontinuous manner in which the applying of torsion is temporarily stopped and then the applying of torsion is performed, and the removing of a surface defect increases the amount of torsional rotation or the shear strain applied to the metal bar.

A description is given of a method and a device for forging a rod-shaped workpiece (5) which is deformed with the aid of forging tools (1, 2, 3, 4) in the sense of a cross-sectional displacement perpendicular to the forging axis (a) and is subjected to an axial advancement and possibly a rotation about the forging axis (a) during the pauses in the engagement of the forging tools (1, 2, 3, 4). In order to achieve an advantageous grain refinement, it is proposed that the workpiece (5) is deformed in the sense of the cross-sectional displacement perpendicular to the forging axis (a) in a bending zone (13) between two central supports (11) by means of the forging tools (1, 2, 3, 4) acting on the workpiece (5) radially in relation to the forging axis (a).

A description is given of a method and a device for forging a rod-shaped workpiece (5) which is deformed with the aid of forging tools (1, 2, 3, 4) in the sense of a cross-sectional displacement perpendicular to the forging axis (a) and is subjected to an axial advancement and possibly a rotation about the forging axis (a) during the pauses in the engagement of the forging tools (1, 2, 3, 4). In order to achieve an advantageous grain refinement, it is proposed that the workpiece (5) is deformed in the sense of the cross-sectional displacement perpendicular to the forging axis (a) in a bending zone (13) between two central supports (11) by means of the forging tools (1, 2, 3, 4) acting on the workpiece (5) radially in relation to the forging axis (a).

A rail exhibits a high 0.2% proof stress after shipping, which is effective for improving rolling contact fatigue resistance of the rail, the rail having a chemical composition containing C: 0.70% to 0.85%, Si: 0.1% to 1.5%, Mn: 0.4% to 1.5%, P: 0.035% or less, S: 0.010% or less, and Cr: 0.05% to 1.50%, with the balance being Fe and inevitable impurities, and exhibiting, at least 90 days after a preparation date of a steel material inspection certificate of the rail which describes at least a measurement result of a 0.2% proof stress of a head of the rail, an improvement margin of a 0.2% proof stress of 40 MPa or more, relative to the 0.2% proof stress described in the steel material inspection certificate.

A rail exhibits a high 0.2% proof stress after shipping, which is effective for improving rolling contact fatigue resistance of the rail, the rail having a chemical composition containing C: 0.70% to 0.85%, Si: 0.1% to 1.5%, Mn: 0.4% to 1.5%, P: 0.035% or less, S: 0.010% or less, and Cr: 0.05% to 1.50%, with the balance being Fe and inevitable impurities, and exhibiting, at least 90 days after a preparation date of a steel material inspection certificate of the rail which describes at least a measurement result of a 0.2% proof stress of a head of the rail, an improvement margin of a 0.2% proof stress of 40 MPa or more, relative to the 0.2% proof stress described in the steel material inspection certificate.

A tube assembly includes at least first and second tubes configured for coupling at respective ends. The first and second tubes each include a base material, and a weld interface at the respective end. The weld interface is proximate to an inner diameter and an outer diameter of the first and second tubes, and includes a weld interface segment extending therebetween. A work hardened weld assembly couples the base material of each of the first and second tubes. The work hardened weld assembly includes a weld fusion zone between the weld interfaces of the first and second tubes and the weld interface segments of the first and second tubes. The weld fusion zone is work hardened and at least the weld interface segments of the first and second tubes are work hardened between the work hardened weld fusion zone and the base material of the first and second tubes.