# US 10,500,672 B2 · Methods and apparatus for welding work pieces having dissimilar compositions

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- Number: US 10,500,672 B2
- Document ID: US10500672B2
- Status: Granted
- Kind: B2
- Application number: 14/925,685
- Filed: 2015-10-28
- Published: 2016-08-04
- Granted: 2019-12-10
- Earliest claimed: 2015-02-04
- Assignees: Fisher Controls International LLC
- Applicants: Fisher Controls International LLC
- Inventors: Donald R. Bush; Nicholas B. Rohrdanz
- Web page: https://patentgrep.com/patent/US10500672B2

## CPC

- B23K 9/232: {of different metals}
- B23K 9/04: Welding for other purposes than joining, e.g. built-up welding
- B23K 9/24: Features related to electrodes
- B23K 2101/06: Tubes
- B23K 2103/04: Steel {or steel} alloys
- B23K 2103/18: Dissimilar 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

The example methods and apparatus reduce and/or eliminate adverse effects of welding work pieces having dissimilar compositions. An example method includes depositing a first weld layer on a first end of a first work piece. The first work piece has a first content of a metallic element and the first weld layer has a second content of the metallic element higher than the first content. The example method includes depositing a second weld layer between the first weld layer and a second end of a second work piece to couple the first work piece to the second work piece. The second weld layer has a third content of the metallic element higher than the second content, and the second work piece has a fourth content of the metallic element higher than the first content.

## Claims

### Claim 1

An apparatus comprising:
a first work piece having a first content of chromium by percentage of weight or mass;
a second work piece having a second content of chromium;
a base welded between the first work piece and the second work piece to couple the first work piece to the second work piece, the base having a same content of chromium as the first work piece, the base having a first end and a second end opposite the first end;
a first weld layer deposited on the first end of the base between the first end of the base and the first work piece;
a second weld layer deposited on the second end of the base, the second weld layer having a third content of chromium higher than the first content and lower than the second content; and
a third weld layer deposited between the second weld layer and the second work piece, the third weld layer having a fourth content of chromium higher than the third content and lower than the second content.

### Claim 2 (depends on 1)

The apparatus of claim 1, wherein the first and second work pieces are pipes.

### Claim 3 (depends on 1)

The apparatus of claim 1, wherein the second weld layer forms a first bevel on the second end of the base.

### Claim 4 (depends on 3)

The apparatus of claim 3, wherein the third weld layer is deposited between the first bevel of the first weld layer and a second bevel on the second work piece.

### Claim 5 (depends on 1)

The apparatus of claim 1 further comprising weld layers disposed between the second weld layer and the third weld layer, each of the weld layers having a content of chromium that is higher than an adjacent one of the weld layers.

### Claim 6 (depends on 1)

The apparatus of claim 1, wherein the first weld layer has a same content of chromium as the first work piece and the base.