# US 2013/0153543 A1 · Overlay welding method and overlay welding apparatus

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- Number: US 2013/0153543 A1
- Document ID: US20130153543A1
- Status: Published application
- Kind: A1
- Application number: 13/714,566
- Filed: 2012-12-14
- Published: 2013-06-20
- Earliest claimed: 2011-12-16
- Assignees: Mitsubishi Heavy Industries, Ltd.
- Inventors: Shuho Tsubota; Yohei Tsuruta
- Web page: https://patentgrep.com/patent/US20130153543A1

## CPC

- B23K 26/0823: {Devices involving rotation of the workpiece}
- B23K 26/0093: {combined with mechanical machining or metal-working covered by other subclasses than B23K}
- B23K 26/0869: {Devices involving movement of the laser head in at least one axial direction}
- B23K 26/12: in a special environment or atmosphere, e.g. in an enclosure
- B23K 26/32: taking account of the properties of the material involved
- B23K 26/342: Build-up welding
- B23K 35/0244: {Powders, particles or spheres; Preforms made therefrom}
- B23K 35/0261: {Rods, electrodes or wires}
- B23K 35/3046: {Co as the principal constituent}
- B23K 2103/50: {Inorganic materials other than metals or composite materials}
- B23K: SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM

## Abstract

To facilitate overlay welding while securing a certain hardness of an overlaid portion and preventing welding defects, an overlay welding method for performing overlay welding on a surface P to be overlaid of a base material 50 includes a preparing step of forming a bottomed depression 51, with the surface P to be overlaid being a circumferential surface 51a thereof, and an overlaying step at which a filler material is fed toward a bottom face 51b of the depression 51, and a laser beam as a heat source is irradiated on the bottom face 51b of the depression 51 to which the filler material is fed, thereby forming an overlaid portion W reaching the surface P to be overlaid, while filling the bottom face 51b of the depression 51 with a melted filler material.

## Claims

### Claim 1

An overlay welding method for performing overlay welding on a surface to be overlaid of a base material, the method comprising:
a preparing step of forming a bottomed depression, with the surface to be overlaid being a circumferential surface thereof; and
an overlaying step at which a filler material is fed toward a bottom face of the depression, and a laser beam as a heat source is irradiated on the bottom face of the depression to which the filler material is fed, thereby forming an overlaid portion reaching the surface to be overlaid, while filling the bottom face of the depression with the melted filler material.

### Claim 2 (depends on 1)

The overlay welding method according to claim 1, wherein a new overlaid portion is further layered on the formed overlaid portion at the overlaying step.

### Claim 3 (depends on 1)

The overlay welding method according to claim 1, wherein the filler material is heated and fed at the overlaying step.

### Claim 4 (depends on 1)

The overlay welding method according to claim 1, wherein at the overlaying step, the base material is preheated before forming the overlaid portion, and the base material is post-heated after the overlaid portion is formed.

### Claim 5 (depends on 1)

The overlay welding method according to claim 1, wherein at the overlaying step, feeding of the filler material and irradiation of a laser beam for melting the filler material are performed for plural times.

### Claim 6 (depends on 1)

The overlay welding method according to claim 1, wherein at the preparing step, a corner connecting the circumferential surface of the depression and the bottom face of the depression is formed in a circular arc shape.

### Claim 7 (depends on 1)

The overlay welding method according to claim 1, wherein at the preparing step, the bottom face of the depression is formed in a flat shape or a concave shape having a large angle of aperture.

### Claim 8 (depends on 1)

The overlay welding method according to claim 1, comprising:
a re-preparing step of forming a new depression reaching the bottom face of the depression in the base material after the overlaying step; and
a re-overlaying step of performing overlay welding to the new depression similarly to the overlaying step.

### Claim 9 (depends on 1)

The overlay welding method according to claim 1, comprising a machining step at which a through hole is formed in the base material along a center line of the depression after the overlaying step or the re-overlaying step.

### Claim 10 (depends on 1)

The overlay welding method according to claim 1, wherein at the preparing step, the bottom face of the depression is formed by blocking one opening of the through hole by a blocking member formed of a same material as that of the filler material or a same material as that of the base material, while designating a circumferential surface of the through hole formed in the base material itself as the surface to be overlaid.

### Claim 11 (depends on 1)

The overlay welding method according to claim 1, wherein at the overlaying step, feeding of the filler material and irradiation of the laser beam are performed so as to be away from the center line of the depression, a feeding position of the filler material and an irradiation position of the laser beam are moved upward so as to be away from the bottom face of the depression, and the base material is rotated around the center line of the depression to form the overlaid portion.

### Claim 12 (depends on 1)

The overlay welding method according to claim 1, wherein at the preparing step, a bottomed annular groove formed in the base material itself is designated as the depression, with an outer circumferential surface thereof being the surface to be overlaid.

### Claim 13 (depends on 12)

The overlay welding method according to claim 12, wherein a circumferential surface on an inner periphery side of the depression formed of the annular groove is a tapered surface with a groove width being gradually narrowed toward a bottom face.

### Claim 14 (depends on 12)

The overlay welding method according to claim 12, comprising a machining step at which, after the overlaying step, the inner peripheral side of the annular groove is cut to form a through hole penetrating the base material.

### Claim 15 (depends on 1)

The overlay welding method according to claim 1, wherein at the preparing step, a stepped portion is provided by cutting a circumferential surface of an opening in a through hole formed in the base material itself, a circumferential surface of the stepped portion is designated as the surface to be overlaid, and an insertion member formed of a same material as that of the filler material or a same material as that of the base material and having an outer circumferential surface abutting on the circumferential surface of the through hole is inserted into the through hole, thereby forming the depression, which is an annular groove by the stepped portion and the insertion member.

### Claim 16 (depends on 15)

The overlay welding method according to claim 15, wherein the insertion member is formed in a divided manner.

### Claim 17 (depends on 15)

The overlay welding method according to claim 15, wherein the insertion member is cooled.

### Claim 18 (depends on 1)

The overlay welding method according to claim 1, wherein
at the preparing step, the depression is formed as a circular annular groove, and
at the overlaying step, feeding of the filler material and irradiation of the laser beam are performed toward the bottom face of the depression, a feeding position of the filler material and an irradiation position of the laser beam are moved upward so as to be away from the bottom face of the depression, and the base material is rotated around a center line of the circular annular groove in the depression to form the overlaid portion.

### Claim 19

An overlay welding apparatus that includes a bottomed depression provided to a base material and performs overlay welding, while designating the circumferential surface of the depression as a surface to be overlaid, the apparatus comprising:
a filler material feeder that feeds a filler material;
a beam irradiation unit that irradiates a laser beam, which becomes a heat source for melting the filler material;
a shielding gas feeder that feeds shielding gas to an atmosphere in which a filler material is melted by a laser beam;
a rotation unit that rotates the base material around a center line of the depression; and
a moving unit that supports the filler material feeder and the beam irradiation unit so that a feeding position of a filler material fed by the filler material feeder and an irradiation position of a laser beam irradiated by the beam irradiation unit reach a bottom face of the depression, while being away from the center line of the depression, and moves the feeding position of the filler material and the irradiation position of the laser beam along the center line of the depression.

### Claim 20

An overlay welding apparatus that includes a depression formed of a circular annular groove provided to a base material and performs overlay welding, designating the depression as a groove for welding, the apparatus comprising:
a filler material feeder that feeds a filler material;
a beam irradiation unit that irradiates a laser beam, which becomes a heat source for melting the filler material;
a shielding gas feeder that feeds shielding gas to an atmosphere in which a filler material is melted by a laser beam;
a rotation unit that rotates the base material around a center line of a circular annular groove in the depression; and
a moving unit that supports the filler material feeder and the beam irradiation unit so that a feeding position of a filler material fed by the filler material feeder and an irradiation position of a laser beam irradiated by the beam irradiation unit reach a bottom face of the depression, and moves the feeding position of the filler material and the irradiation position of the laser beam around the center line of the circular annular groove in the depression.
