This disclosure is related to high yield strength steel where yield strength can be increased without significantly affecting ultimate tensile strength (UTS) and in some cases, higher yield strength can be obtained without significant decrease in ultimate tensile strength and total elongation.

This disclosure is related to high yield strength steel where yield strength can be increased without significantly affecting ultimate tensile strength (UTS) and in some cases, higher yield strength can be obtained without significant decrease in ultimate tensile strength and total elongation.

An article and a method of manufacturing the article is disclosed. The method includes providing the article including a substrate and a coating at least partially disposed on the substrate. The coating includes an outer surface. The coating further includes platinum and chromium. The method further includes applying cold work to the outer surface of the coating to produce a cold-worked layer extending from the outer surface of the coating to a cold work depth. The cold-worked layer includes approximately 45% cold work. The cold work depth is between about 30 microns to about 150 microns from the outer surface of the coating.

Disclosed are a wire rod and a component, for cold forging, each having excellent delayed fracture resistance characteristics and applicable to high-strength bolts and the like and a manufacturing method therefor.

According to an embodiment, a heat-treated component having excellent delayed fracture resistance characteristics includes, in percent by weight (wt %), 0.3 to 0.5% of C, 0.01 to 0.3% of Si, 0.3 to 1.0% of Mn, at least two types selected from the group consisting of 0.3 to 1.5% of Cr, 0.3 to 1.5% of Mo, and 0.01 to 0.4% of V, and the balance being Fe and other impurities, includes, as a microstructure, a tempered martensite phase in an area fraction of 95% or more, and includes V-based carbides having a diameter of 300 nm or less at 10/100 μm.sup.2 or more.

Disclosed are a wire rod and a component, for cold forging, each having excellent delayed fracture resistance characteristics and applicable to high-strength bolts and the like and a manufacturing method therefor.

According to an embodiment, a heat-treated component having excellent delayed fracture resistance characteristics includes, in percent by weight (wt %), 0.3 to 0.5% of C, 0.01 to 0.3% of Si, 0.3 to 1.0% of Mn, at least two types selected from the group consisting of 0.3 to 1.5% of Cr, 0.3 to 1.5% of Mo, and 0.01 to 0.4% of V, and the balance being Fe and other impurities, includes, as a microstructure, a tempered martensite phase in an area fraction of 95% or more, and includes V-based carbides having a diameter of 300 nm or less at 10/100 μm.sup.2 or more.

The invention relates to a method and a device for strengthening the surface of workpieces, in particular of metal ones, by mechanical effects accompanying the impact of small projectiles or by mechanical effects accompanied by the impact of a shockwave induced by plasma created by electric evaporation of a metal foil. The device comprises a polymer strip with a metal foil on the surface of the side diverted from the surface of the workpiece in which foil bridges are formed to form projectiles, further comprising two electrodes and adjacent to the metal foil located on the polymer strip, wherein bridges are formed between the contact surface areas of the metal foil, and the electrodes and between which the plasma is formed, are mounted in a support body, through which flat conductors and are connected to a switch for switching large currents and high voltages with a high-voltage source. The polymer strip with the metal foil tightly abuts the support body with the electrodes and the electrodes and protrude above the upper surface of the support body to provide electric contact with the contact surface areas of the applied metal foil. The method of strengthening the surface of workpieces by means of the device according to the invention consists in that one cycle of strengthening the surface of workpieces involves the action of an electric current pulse supplied from a high voltage source after closing the switch by conductors to electrodes between which a high voltage is applied, thereby shorting the circuit on the metal foil at the location of the bridges to form a plasma expanding and by a compressive force acting on the polymer strip part of which hits as a projectile the surface of the workpiece. The plasma is generated by the electric current pulse, in addition to the expansion pressure, is also accelerated by the electromagnetic Lorentz force caused by the passage of electric current, through this plasma in the generated magnetic field.

A forming sheet metal part (1) for a vehicle frame includes: a first portion (2) being locally heat-softened after the sheet metal part (1) has been formed out. The part (1) further includes a dedicated three-dimensional distortion-absorbing area (4), defining an internal boundary (6) within which the first portion (2) is to be locally heat-softened after the sheet metal part (1) has been formed out. The distortion-absorbing area (4) is dimensioned such that once said locally heat-softening step has been performed, the internal boundary (6) is adjacent to the first portion (2) and encloses the first portion (2) to absorb the dimensional distortions induced by the locally heat-softened first portion. The invention further relates to a method for producing a forming sheet metal part (1).

A forming sheet metal part (1) for a vehicle frame includes: a first portion (2) being locally heat-softened after the sheet metal part (1) has been formed out. The part (1) further includes a dedicated three-dimensional distortion-absorbing area (4), defining an internal boundary (6) within which the first portion (2) is to be locally heat-softened after the sheet metal part (1) has been formed out. The distortion-absorbing area (4) is dimensioned such that once said locally heat-softening step has been performed, the internal boundary (6) is adjacent to the first portion (2) and encloses the first portion (2) to absorb the dimensional distortions induced by the locally heat-softened first portion. The invention further relates to a method for producing a forming sheet metal part (1).

A steel part includes a steel sheet substrate and a coating on at least one surface of the steel sheet substrate. The coating includes between 0.2 and 0.7% by weight of Al, with a remainder of the metal coating being Zn and inevitable impurities. The steel sheet substrate and the coating have at least one deformation. An outer surface of the coating has a waviness Wa.sub.0.8 of less than or equal to 0.43 μm.

A steel part includes a steel sheet substrate and a coating on at least one surface of the steel sheet substrate. The coating includes between 0.2 and 0.7% by weight of Al, with a remainder of the metal coating being Zn and inevitable impurities. The steel sheet substrate and the coating have at least one deformation. An outer surface of the coating has a waviness Wa.sub.0.8 of less than or equal to 0.43 μm.