Abstract: A method for creating an iridescent effect on a surface through formation of wavelets on the source can include using a pulse of laser beams sent to the surface in juxtaposed optical fields of a focusing system. A scanner scans the surface using laser beams along a series of lines that follow each other in a relative direction of travel of the part and of the scanner and a series of lines that lie in continuation of each other in a direction perpendicular to the relative direction of travel. The optical fields overlap in an overlapping area having a width that is twice the diameter of the pulse laser beam up to 2 cm. Two lines lying in continuation of each other overlap at a junction and between the two series of lines follow each other in a relative direction of travel of the part and the scanner.

Abstract: A laser descaling device and process includes a first laser sending a ray to the product to be descaled, reflected rays being intercepted by sensors that send collected information into a processing unit that calculates the absorption of the ray by the surface of the product, deduces the emissivity of the oxidized surface in the direction of the reflected rays, and correlates this emissivity with reference information prerecorded inside the processing unit; a second laser sends a ray onto the surface of the product, the spots of the rays covering the entire surface to be descaled, the second laser being controlled by a control unit receiving information provided by the processing unit making it possible to determine the operating parameters to be imposed on the second laser to obtain the descaling of the surface of the product, compared with experimental results prerecorded in the control unit.

Abstract: Method for recovering Cr from a pickling bath of an aqueous solution containing sulphate and Cr from a pickled metal, the method including: -forming an aqueous two-phase system from a portion of the pickling bath and a polymer including an unhindered ether function, the proportion of polymer in the ternary mixture including the pickling bath, considered to be a unique chemical component, water and polymer, ranging between the line of the equation «weight % of polymer=100%?weight % of pickling bath» and the binodal curve of the pickling bath/polymer mixture, the two-phase aqueous system including polymer and non-polymer phases;—separating the respective phases;—allowing precipitates containing Cr to form in the polymer phase;—carrying out solid/liquid separation of the polymer phase to separate the polymer and the precipitates containing Cr;—and processing the precipitates to recover the Cr. A facility is also disclosed.

Abstract: Method for creating an iridescent visual effect on the surface of a part, using a laser beam having a pulse duration of less than a nanosecond sent onto said surface in the optical field of the focusing system of a device comprising also a laser source and a scanner, to apply wavelets having the same orientation to said surface over the pulse width. The scanner scans the surface using laser radiation along a series of consecutive lines, or a matrix of points using relative movement of said surface and the device, the width of each line or the dimension of each point of each matrix being equal to the pulse diameter. Between the carrying out of the scanning along two consecutive lines or two adjacent points the polarization of the laser beam is modified to create wavelets having different orientations on two consecutive lines or two adjacent points.

Abstract: A method for creating an iridescent effect on a surface through formation of wavelets on the source can include using a pulse of laser beams sent to the surface in juxtaposed optical fields of a focusing system. A scanner scans the surface using laser beams along a series of lines that follow each other in a relative direction of travel of the part and of the scanner and a series of lines that lie in continuation of each other in a direction perpendicular to the relative direction of travel. The optical fields overlap in an overlapping area having a width that is twice the diameter of the pulse laser beam up to 2 cm. Two lines lying in continuation of each other overlap at a junction and between the two series of lines follow each other in a relative direction of travel of the part and the scanner.

Abstract: A laser descaling device and process includes a first laser sending a ray to the product to be descaled, reflected rays being intercepted by sensors that send collected information into a processing unit that calculates the absorption of the ray by the surface of the product, deduces the emissivity of the oxidized surface in the direction of the reflected rays, and correlates this emissivity with reference information prerecorded inside the processing unit; a second laser sends a ray onto the surface of the product, the spots of the rays covering the entire surface to be descaled, the second laser being controlled by a control unit receiving information provided by the processing unit making it possible to determine the operating parameters to be imposed on the second laser to obtain the descaling of the surface of the product, compared with experimental results prerecorded in the control unit.