The ultra-fine wire fabricating apparatus comprises a feeder assembly, a stationary die, and a rotary die holder. The feeder assembly supplies a wire. The stationary die comprises a hollow inclined channel configured on an inner surface of the stationary die. The hollow inclined channel is configured to receive the wire from the feeder assembly. The rotary die holder configured to receive the wire from the stationary die and simultaneously torsionally deform the wire, wherein the rotary die holder rotates relative to the stationary die to produce the ultra-fine wire with improved mechanical properties. The method ensures continuous grain refinement of wires. The wires are severe plastic deformed using the combined effects of the stationary die and rotary die holder. The mechanical properties of the raw materials are improved due to a grain refinement and microstructure evolution caused by plastic deformation.

The present invention relates to a method and an apparatus for treating already galvanized steel parts having a zinc coating, in particular for remanufacturing used galvanized steel parts. The method comprises the following steps: A) checking the galvanized steel part for suitability with a view to remanufacturing; B) preparing the galvanized steel part mechanically and/or chemically; and C) rejuvenating the zinc coating of the steel part.

The present invention provides a method for manufacturing a torsion beam, the method comprising: a planarization step, in which a protruding portion of an upper mold presses the opposite end portions in the width direction of the blank to be plastically deformed to be flat while the opposite end portions in the width direction of the blank are supported by a side cam to face each other; a welding and bonding step for bonding the planarized opposite end portions in the width direction of the blank via welding; and a quenching step for heating the welded and bonded blank within a range of 900 to 970? C. for a retaining time within a range of 1 to 20 minutes and for cooling down the blank in a treatment liquid including at least one of water and oil in a range of 20 to 90? C.

A method is disclosed for producing components from an austenitic lightweight steel which is metastable in its initial state, by forming of a sheet, a circuit board or a pipe in one or more steps, exhibiting a temperature-dependent TRIP and/or TWIP effect during forming. To obtain a component with, in particular, high toughness, the forming is carried out at a temperature above room temperature, at 40 to 160 C., which avoids the TRIP/TWIP effect, and to achieve in particular high component strength, the forming is carried out at a temperature below room temperature, at 65 to 0 C., which enhances the TRIP/TWIP effect.

A method is disclosed for producing components from an austenitic lightweight steel which is metastable in its initial state, by forming of a sheet, a circuit board or a pipe in one or more steps, exhibiting a temperature-dependent TRIP and/or TWIP effect during forming. To obtain a component with, in particular, high toughness, the forming is carried out at a temperature above room temperature, at 40 to 160 C., which avoids the TRIP/TWIP effect, and to achieve in particular high component strength, the forming is carried out at a temperature below room temperature, at 65 to 0 C., which enhances the TRIP/TWIP effect.

A high manganese content deformed reinforcing bar having an austenite single phase microstructure has excellent bending workability. A deformed reinforcing bar includes a chemical composition containing, in mass %, C: 0.7% or more and 1.2% or less, Si: 1.0% or less, Mn: 9% or more and 15% or less, Cr: 1.0% or less, P: 0.03% or less, and S: 0.05% or less, the balance consisting of Fe and inevitable impurities; and a microstructure comprising an austenite single phase. The ratio of the difference between the maximum and minimum hardness at a periphery of a cross-section perpendicular to the longitudinal direction with respect to a central average hardness is 15% or less. Two or more ribs extend in the longitudinal direction at equal intervals in a cross-sectional circumferential direction. The ratio of the difference between the maximum and minimum width of the ribs to the minimum width is 50% or less.

A high manganese content deformed reinforcing bar having an austenite single phase microstructure has excellent bending workability. A deformed reinforcing bar includes a chemical composition containing, in mass %, C: 0.7% or more and 1.2% or less, Si: 1.0% or less, Mn: 9% or more and 15% or less, Cr: 1.0% or less, P: 0.03% or less, and S: 0.05% or less, the balance consisting of Fe and inevitable impurities; and a microstructure comprising an austenite single phase. The ratio of the difference between the maximum and minimum hardness at a periphery of a cross-section perpendicular to the longitudinal direction with respect to a central average hardness is 15% or less. Two or more ribs extend in the longitudinal direction at equal intervals in a cross-sectional circumferential direction. The ratio of the difference between the maximum and minimum width of the ribs to the minimum width is 50% or less.

Rather than using a conventional stamping forming process with steels having high ultimate tensile strength and relatively low initial yield, tubular hydroforming techniques are introduced to synergize with BIW part forming, or forming of other load bearing parts. Such steels can have ultimate tensile strengths of greater than 1000 MPa and initial yields of less than 360 MPa In some embodiments, the steels have elongation of at least 40%. Such steels can include retained austenite.

A dual phase stainless steel pipe includes tensile yield strength YS.sub.LT of 689.1 MPa to 1000.5 MPa in a pipe axis direction of the dual phase stainless steel pipe, in which the tensile yield strength YS.sub.LT, a compressive yield strength YS.sub.LC in the pipe axis direction, a tensile yield strength YS.sub.CT in a pipe circumferential direction of the dual phase stainless steel pipe, and a compressive yield strength YS.sub.CC in the pipe circumferential direction satisfy all Expressions (1) to (4),
0.90YS.sub.LC/YS.sub.LT1.11(1)
0.90YS.sub.CC/YS.sub.CT1.11(2)
0.90YS.sub.CC/YS.sub.LT1.11(3)
0.90YS.sub.CT/YS.sub.LT1.11(4).

A dual phase stainless steel pipe includes tensile yield strength YS.sub.LT of 689.1 MPa to 1000.5 MPa in a pipe axis direction of the dual phase stainless steel pipe, in which the tensile yield strength YS.sub.LT, a compressive yield strength YS.sub.LC in the pipe axis direction, a tensile yield strength YS.sub.CT in a pipe circumferential direction of the dual phase stainless steel pipe, and a compressive yield strength YS.sub.CC in the pipe circumferential direction satisfy all Expressions (1) to (4),
0.90YS.sub.LC/YS.sub.LT1.11(1)
0.90YS.sub.CC/YS.sub.CT1.11(2)
0.90YS.sub.CC/YS.sub.LT1.11(3)
0.90YS.sub.CT/YS.sub.LT1.11(4).