A method of strengthening a component made of a metallic material. The method includes subjecting the component to a mechanical grinding process incorporating a relative motion between a tool and the component forming a gradient structure on the surface of the component, resulting in increased tensile strength of the component. A method of strengthening a component made of a TWIP steel. The method includes subjecting the component made of TWIP steel to a mechanical grinding process incorporating a relative motion between a tool and the component forming a gradient structure containing a surface nanolaminate layer, a shear band layer, and an inner deformation twinned layer, resulting in increased tensile strength of the component. A component made of a TWIP steel containing a gradient structure with a surface nanolaminate layer, a shear band layer, and a deformation twinned layer.

An ultrasonic roller burnishing system comprises a roller and a controller. The roller is configured to be pressed against a surface of a workpiece to a pressing depth, roll on the surface at a feed rate, and vibrate at an ultrasonic frequency under a back pressure. The roller is pressed and rolled by a motion unit which is driven by a drive motor. The vibrating of the roller is driven by an ultrasonic vibration unit with an input current inputted thereinto. The controller is configured to adjust at least one of the pressing depth, the back pressure, the input current and the feed rate based on an expected residual compressive stress and a real time output power of the drive motor, to generate a residual compressive stress in the workpiece which is in an expected range predetermined based on the expected residual compressive stress.

An ultrasonic roller burnishing system comprises a roller and a controller. The roller is configured to be pressed against a surface of a workpiece to a pressing depth, roll on the surface at a feed rate, and vibrate at an ultrasonic frequency under a back pressure. The roller is pressed and rolled by a motion unit which is driven by a drive motor. The vibrating of the roller is driven by an ultrasonic vibration unit with an input current inputted thereinto. The controller is configured to adjust at least one of the pressing depth, the back pressure, the input current and the feed rate based on an expected residual compressive stress and a real time output power of the drive motor, to generate a residual compressive stress in the workpiece which is in an expected range predetermined based on the expected residual compressive stress.

A repaired oxidation and corrosion resistant coating may comprise a repair material applied to a damaged portion of the oxidation and corrosion resistant coating. The repair material may be free of hexavalent chromium and may be compatible with a plurality of oxidation and corrosion resistant materials that comprise hexavalent chromium. The repair material may be burnished. The oxidation and corrosion resistant coating may comprise hexavalent chromium.

A repaired oxidation and corrosion resistant coating may comprise a repair material applied to a damaged portion of the oxidation and corrosion resistant coating. The repair material may be free of hexavalent chromium and may be compatible with a plurality of oxidation and corrosion resistant materials that comprise hexavalent chromium. The repair material may be burnished. The oxidation and corrosion resistant coating may comprise hexavalent chromium.

A method for deep roll peening a workpiece includes deep roll peening a workpiece by moving the workpiece along a feed path through multiple groups of opposed rollers that are arranged in series. Each group of opposed rollers includes a rim that defines a workpiece engagement surface that exerts a deep roll peening force on the workpiece. A deep roll peening system includes multiple groups of opposed rollers. Each of the opposed rollers is rotatably mounted and has a rim that defines a workpiece engagement surface. The workpiece engagement surfaces are spaced apart from each other by a gap. The groups are arranged in series such that the gaps define a feed path for receiving a workpiece into serial contact with the workpiece engagement surfaces.

A method for deep roll peening a workpiece includes deep roll peening a workpiece by moving the workpiece along a feed path through multiple groups of opposed rollers that are arranged in series. Each group of opposed rollers includes a rim that defines a workpiece engagement surface that exerts a deep roll peening force on the workpiece. A deep roll peening system includes multiple groups of opposed rollers. Each of the opposed rollers is rotatably mounted and has a rim that defines a workpiece engagement surface. The workpiece engagement surfaces are spaced apart from each other by a gap. The groups are arranged in series such that the gaps define a feed path for receiving a workpiece into serial contact with the workpiece engagement surfaces.

A method for producing a steel part and corresponding steel part includes casting a steel having a composition comprising: 0.10%C0.35%, 0.8%Si2.0%, 1.8%Mn2.5%, P0.1%, 0%S0.4%, 0%Al1.0%, N0.015%, 0%Mo0.4%, 0.02%Nb0.08%, 0.02%Ti0.05%, 0.001%B0.005%, 0.5%Cr1.8%, 0%V0.5%, 0%Ni0.5%, to obtain a semi-product, hot rolling the semi-product at a hot rolling starting temperature higher than 1000 C. and cooling the product through air to room temperature to obtain a hot rolled steel part having a microstructure consisting of 70% to 90% of bainite, 5% to 25% of M/A compounds and at most 25% of martensite. The bainite and the M/A compounds contain retained austenite such that the total content of retained austenite in the steel is comprised between 5% and 25%, the carbon content of the retained austenite being comprised between 0.8% and 1.5%.

The invention relates to a roller burnishing tool 10 with a base body 12 extending along a longitudinal center axis 11, at least one roller holder 14 arranged radially adjustably on the base body 12, which holds a roller 15 rotatably, and an adjusting device 16 arranged in the base body 12 for adjusting the roller holder 14 cooperates in the radial direction with the roller holder 14. According to the invention, the roller holder 14 has a holder arm 18b holding the roller 15, which can be pivoted out in a radial direction by the adjusting device 16 relative to the base body 12 in a radial direction.

A method of strengthening a component made of a metallic material. The method includes subjecting the component to a mechanical grinding process incorporating a relative motion between a tool and the component forming a gradient structure on the surface of the component, resulting in increased tensile strength of the component. A method of strengthening a component made of a TWIP steel. The method includes subjecting the component made of TWIP steel to a mechanical grinding process incorporating a relative motion between a tool and the component forming a gradient structure containing a surface nanolaminate layer, a shear band layer, and an inner deformation twinned layer, resulting in increased tensile strength of the component. A component made of a TWIP steel containing a gradient structure with a surface nanolaminate layer, a shear band layer, and a deformation twinned layer.