Laser cladding of tubes

Abstract

The present invention relates to an apparatus for laser cladding of a curved surface comprising: (a) an elongated arm having first and second ends and defining a chamber through the arm from the first end to the second end; (b) a laser delivery source connected to a focusing lens mounted in a housing within an opening on the first end of the arm for delivering a laser beam through the chamber; (c) a delivery head mounted on the second end of the arm comprised of (i) an enclosure having an inlet for receiving the laser and an outlet for delivering the laser to the curved surface, (ii) a powder nozzle for delivering a cladding powder to an inner surface of the curved surface, and (iii) a reflective surface for reflecting the laser to exit through the outlet; (d) mounting means for rotating the curved surface for the cladding of the curved surface; and (e) indexing means for moving the arm substantially parallel to a longitudinal axis of the curved surface so as to clad the curved surface during the rotation of the curved surface. Typically, the curved surface is part of the inner surface of a tube used in industrial applications.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]Not Applicable.STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT[0002]Not Applicable.REFERENCE TO A “COMPUTER LISTING APPENDIX SUBMITTED ON A COMPACT DISC”[0003]Not Applicable.BACKGROUND OF THE INVENTION[0004](1) Field of the Invention[0005]The present invention relates generally to an apparatus and a process for laser coding of the inner diameter of tubes.[0006](2) Description of the Related Art[0007]Industrial coating or cladding of tubes is well known. In the oil and drilling industry, tubes of various sizes often demand inner diameter coating, welding or cladding with a desired material. Lasers have been utilized as a coating process by melting the coating material with the desired surface to generate a “melt pool” which subsequently hardens.[0008]Laser welding of the inner diameter (ID) of barrels involves the depositing of a liner material prior to welding in the form of paste or powder, or a separate liner tube. In th...

AI Technical Summary

Benefits of technology

[0023]The present disclosure provides for a cladding head apparatus adapted for laser cladding of a surface comprising: (a) an enclosure having an inlet for receiving a laser and an outlet as a laser nozzle for delivering the laser to the surface, (b) a diffuser mounted adjacent to the enclosure having a diffuser nozzle for delivering a cladding powder to the surface; (c) a reflective surface for reflecting the laser to exit through the outlet; and (d) a cover glass within the enclosure mounted adjacent to the laser nozzle for reducing dust and back spatter resulting from the cladding of the surface. The cover glass and the reflective surface are each removably mounted within the enclosure. The cladding head can be mounted on a second end of an elongated arm defining a chamber and coupled to a laser energy source at an opposite first end. The chamber is constructed to allow for the laser to be transmitted through the elongated arm and into the inlet of the enclosure of the cladding head. The reflective surface can be adapted to reflect the laser perpendicular to a longitudinal axis defined by the elongated arm. In an exemplary embodiment, each of the cover glass and the reflective surface is mounted on a removable insert member such that each of the cover glass and the reflective surface is replaceable. The reflective surface is selected from group consisting of a mirror, copper, and fused silica coated with anti-reflective coating.

Problems solved by technology

Powder is difficult to introduce in the vertical position without gravity assist since it tends to clog and interrupt the cladding process.

Many of the previously described devices must have auxiliary services introduced from the laser head end of the tube because access from the opposite end is not available, and cannot be coordinated with the activity provided from the laser end.

Moreover, many of the known devices weld on constantly changing surfaces.

This tends to give a non-uniform and less smooth surface due to the influence of gravity.

If the cladding is done with the pipe in a vertical position, the melt pool tends to not be flattened and can have exaggerated rings or other distortions in the surface.

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