A system for laser-driven propulsion, system comprising a laser source and a target comprising an accelerating part and a projectile part, the accelerating part comprising a metal layer and a porous layer pressed against the metal layer; wherein the laser source is selected to emit pulse beams directed to the metal layer at a fluence below the plasma ablation threshold of the material of the metal layer.

A process for treating a centrifugal compressor wheel includes a combination of cold expansion of at least part of the bore of the wheel to induce residual compressive stresses in a region around the bore, and surface peening at least parts of the compressor wheel such as the back disk and portions of the blades.

The invention relates to a wear-resistant steel with excellent surface quality, which is composed of C: 0.12-0.20%, Si: ≤0.1%, Mn: 0.6-1.20%, Nb: 0.010-0.040%, V: ≤0.01%, Ti: 0.010%-0.030, Al: ≤0.04%, Ni: ≤0.1%, Cu: ≤0.1%, Cr: 0.10-0.40%, Mo: ≤0.1%, B: 0.001-0.005%, Ca: 0.0010-0.0050%, P: ≤0.010%, S: ≤0.0015%, O: ≤0.0012%, N: ≤0.0035%, H: ≤0.0002%, the balance is Fe, and the carbon equivalent CEV≤0.4; PCM≤0.25. The production process flow is: converter smelting->LF refining->VD or Rh high vacuum degassing->continuous casting->heating->rolling->shot blasting->quenching->tempering. The wear-resistant steel of the invention has better surface quality, and there are no surface defects such as air pit, inclusion, hemp pit and pressed iron oxide scale. The depth of surface spots caused by the peeling off iron oxide scale is ≤0.1 mm, and the surface grinding of steel plate cannot be carried out. Based on element design, non-preheating welding and excellent toughness can be further realized.

The invention relates to a wear-resistant steel with excellent surface quality, which is composed of C: 0.12-0.20%, Si: ≤0.1%, Mn: 0.6-1.20%, Nb: 0.010-0.040%, V: ≤0.01%, Ti: 0.010%-0.030, Al: ≤0.04%, Ni: ≤0.1%, Cu: ≤0.1%, Cr: 0.10-0.40%, Mo: ≤0.1%, B: 0.001-0.005%, Ca: 0.0010-0.0050%, P: ≤0.010%, S: ≤0.0015%, O: ≤0.0012%, N: ≤0.0035%, H: ≤0.0002%, the balance is Fe, and the carbon equivalent CEV≤0.4; PCM≤0.25. The production process flow is: converter smelting->LF refining->VD or Rh high vacuum degassing->continuous casting->heating->rolling->shot blasting->quenching->tempering. The wear-resistant steel of the invention has better surface quality, and there are no surface defects such as air pit, inclusion, hemp pit and pressed iron oxide scale. The depth of surface spots caused by the peeling off iron oxide scale is ≤0.1 mm, and the surface grinding of steel plate cannot be carried out. Based on element design, non-preheating welding and excellent toughness can be further realized.

A method for treating a surface of a metallic part in particular of a turbomachine includes a step of shot-peening a surface of the metallic part using metallic beads and a step of cleaning the surface of the metallic part after the shot peening. The cleaning comprises step includes applying a magnetic cleaning paste to the surface of the metallic part in such a way as to remove any residues of metallic beads.

A method for treating a surface of a metallic part in particular of a turbomachine includes a step of shot-peening a surface of the metallic part using metallic beads and a step of cleaning the surface of the metallic part after the shot peening. The cleaning comprises step includes applying a magnetic cleaning paste to the surface of the metallic part in such a way as to remove any residues of metallic beads.

The present invention improves surface roughness by knocking down protruding parts while leaving recessed parts in the surface of a metal product, protrusions/recesses having been formed in said surface via blasting, and improves surface hardness and compressive residual stress. Treatment is performed upon a metal product in which protrusions/recesses have been formed in the surface thereof via blasting. Spherical shot that are less hard than the surface hardness of the metal product and have a particle size that is greater than the width of recessed parts of the protrusions/recesses are sprayed toward and collide against the surface of the metal product as crushing shot, and the protruding parts of the protrusions/recesses formed on the surface of the metal product are selectively knocked down, thereby providing a metal product surface member in which the surface roughness of the metal product has been improved.

A method of cavitation peening may include coupling a moveable water source to a portable nozzle, through a flexible conduit. The method may include positioning the nozzle adjacent a treatment surface and discharging a first and second stream of fluid through a first and second channel of the nozzle, with the second channel concentrically positioned around the first channel. The first stream may have a first pressure, and the second stream may have a second pressure, the first pressure being greater than the second pressure and the two streams combining to generate a cloud of cavitation bubbles.

A method of cavitation peening may include coupling a moveable water source to a portable nozzle, through a flexible conduit. The method may include positioning the nozzle adjacent a treatment surface and discharging a first and second stream of fluid through a first and second channel of the nozzle, with the second channel concentrically positioned around the first channel. The first stream may have a first pressure, and the second stream may have a second pressure, the first pressure being greater than the second pressure and the two streams combining to generate a cloud of cavitation bubbles.

A stabilizer formed by using a metal bar having a solid structure and configured to reduce a displacement between right and left wheels, including a torsion part extending in a vehicle width direction, being capable of a torsional deformation, and having a diameter of 10 to 32 mm, is provided. The stabilizer has a chemical composition containing at least C: 0.15% by mass or more to 0.39% by mass or less, Mn, B, and Fe, and also has a metal structure 90% or more of which is a martensite structure.