53 results about "High speed deformation" patented technology

The present invention relates to a hot-rolled steel sheet, a cold-rolled steel sheet, and a plated steel sheet having improved uniform ductility and local ductility at a high strain rate. A multi-phase hot-rolled steel sheet according to one mode of the present invention has a metallurgical structure having a main phase of ferrite with an average grain diameter of at most 3.0 µm and a second phase including at least one of martensite, bainite, and austenite. In the surface layer, the average grain diameter of the second phase is at most 2.0 µm, the difference (”nH av ) between the average nanohardness of the main phase (nH ±av ) and the average nanohardness of the second phase (nH 2nd av ) is 6.0 - 10.0 GPa, the difference (”ÃnH) of the standard deviation of the nanohardness of the second phase from the standard deviation of the nanohardness of the main phase is at most 1.5 GPa, and in the central portion, the difference (”nH av ) between the average nanohardnesses is at least 3.5 GPa to at most 6.0 GPa and the difference (”ÃnH) between the standard deviations of the nanohardnesses is at least 1.5 GPa.

The invention discloses a method and a device for electromagnetically forming a metal pipe fitting in a radial and axial loading mode. The device mainly comprises an eddy current coil, magnetic field coils and power systems. The eddy current coil generates induced eddy currents, the magnetic field coils generate radial magnetic fields, and the eddy current coil and the magnetic field coils are powered by the power systems. The method and the device have the advantages that electromagnetic force can be radially and axially loaded simultaneously in a procedure for electromagnetically forming the metal pipe fitting, an electromagnetic force loading mode can be adjusted, and accordingly machining requirements of different workpieces can be met; the axial compression type pipe fitting is electromagnetically expanded, so that the thickness reduction of a pipe wall in an expansion procedure can be effectively reduced, the forming limit of a formed workpiece is increased, and the forming performance of the formed workpiece is improved; high-speed deformation experiment conditions in different load forms can be provided for metal pipe fittings by the method for electromagnetically forming the metal pipe fitting in the radial and axial loading mode, and novel experiment measures are provided for research on high-speed deformation mechanisms of materials.

The invention relates to a method for processing the high-speed deformation on the surface of metallic material with nano structure, and particularly provides a method for realizing high-speed processing of the organization structure of ultra-fine grains. On the condition of room temperature or low temperature, by adopting a mechanical treatment method with high-speed plastic deformation, the nanoscale bulky crystalline grain structure on the surface layer of the metallic material is refined as equiaxial submicron crystalline grain or nano crystalline grain to form an ultra-fine organization structure of the crystalline grain on the surface layer of the metallic material. With the increase of the depth to the processing surface, the size of microstructure has the change of gradient, increasing from nanoscale and submicron size to micron size. Compared with the existing processing method for forming a surface ultra-fine crystalline grain structure, the high-speed processing method of the invention greatly reduces the roughness of the surface of the processed metallic material and increases the thickness of a deformation layer, and has simple processing method and high working efficiency.

A method of designing a roller bearing is disclosed upon clarifying mechanisms of damage patterns in respect of two kinds of brinelling, involved in the bearing, wherein white-banded flaking (brittle flaking) is a plastic instability phenomenon appearing under high-speed deformation accompanied by adiabatic shear deformation status with the resultant occurrence of adiabatic shear band (also called white band) inside material of the bearing. This enables all of the damage patterns to be determined upon making comparison between shear strain and shear strain rate, occurring inside the bearing, and discriminated values.

This invention provides a Zn-Al alloy, which is excellent in static deformability, as well as in dynamic deformability, and can be applied to a large structure, and a process useful for producing the Zn-Al alloy. The Zn-Al alloy comprises Zn: 30 to 99% (% by mass; the same shall apply hereinafter) with the balance consisting of Al and unavoidable impurities, wherein the Zn-Al alloy has a texture comprising a ss phase finely dispersed in an a phase or a' phase having an average grain diameter of not more than 5 [mu]m, the maximum diameter of Al-based inclusions is not more than 50 [mu]m, and, at the same time, pores having a equivalent circle diameter of not less than 0.5 mm are absent, and the macrosegregation of Al is less than 3.0%, and the microsegregation of Al is less than 2.0%.

The invention discloses a three-dimensional speckle strain measurement method, comprising: (1) speckle preparation; (2) camera calibration; (3) state information acquisition; (4) computational domain designation; (5) initial point setting; (6) speckle matching; (7) three-dimensional reconstruction; and (8) strain computation. By the above operation steps, the invention provides a three-dimensional speckle strain measurement method, which can effectively obtain high preciseness measurement results in measurements of material characteristic parameters such as full-field vibration measurement, dynamic strain measurement, high speed deformation measurement, fracture mechanics, impact excitation and dynamic material experiments. The invention has the characteristics of convenient measurement operation, high automation degree, exact and reliable results, high efficiency and non-contact measurement.

The invention discloses an electromagnetic pulse forming device and method for a metal sheet. The electromagnetic pulse forming method includes the steps that S1, when the metal sheet to be formed is arranged between a forming die and a forming coil, pressure equipment is used for applying pressure through a blank holder, and accordingly a metal sheet flange area can be prevented from being wrinkled; S2, a first power module is used for supplying a current to the forming coil, and the powered-on forming coil generates a pulsed magnet field at a metal sheet area; a second power module is used for supplying a current to the metal sheet, so that a pulse current is generated in the metal sheet; and the pulse current and the pulsed magnet field act with each other to generate electromagnetic force used for driving the metal sheet to be subjected to high-speed deformation; and S3, the metal sheet to be formed can be deformed through the electromagnetic force. According to the electromagnetic pulse forming device and method, in the mode of directly loading the currents, the current magnitude in the metal sheet can be increased obviously, the influence on the current magnitude by electrical resistivity is small, and the problem of being insufficient in forming force due to the fact that the induced eddy current of a low electric conductivity material is small can be effectively solved.