# US 9,517,523 B2 · System and method of reducing diffusible hydrogen in weld metal > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,517,523 B2 - Document ID: US9517523B2 - Status: Granted - Kind: B2 - Application number: 13/079,521 - Filed: 2011-04-04 - Published: 2011-10-13 - Granted: 2016-12-13 - Earliest claimed: 2010-04-09 - Assignees: Illinois Tool Works Inc. - Applicants: Steven Barhorst; Mario Amata; Joseph C. Bundy - Inventors: Steven Barhorst; Mario Amata; Joseph C. Bundy - Web page: https://patentgrep.com/patent/US9517523B2 ## CPC - B23K 9/164: {making use of a moving fluid} - B23K 9/1043: {characterised by the electric circuit (B23K9/1012 takes precedence)} - B23K 9/173: and of a consumable electrode - B23K 35/38: Selection of media, e.g. special atmospheres for surrounding the working area - 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 This disclosure relates generally to arc welding. In an embodiment, a welding system has a welding gas supply system configured to supply a gas flow including a shielding gas and a fluorine-containing gas to a weld pool. Furthermore, the shielding gas is configured to control an atmosphere surrounding the weld pool, the fluorine-containing gas is configured to reduce diffusible hydrogen in the weld pool, and the fluorine-containing gas is substantially free of sulfur. ## Claims ### Claim 1 A welding gas mixture delivered to an arc welding system during an arc welding operation, wherein the welding gas mixture comprises: a shielding gas that provides an atmosphere surrounding a weld pool formed by the arc welding system during the arc welding operation; and a carbon-based fluorine-containing gas that reduces diffusible hydrogen in the weld pool, wherein the welding gas mixture comprises approximately 0.1 to approximately 10 percent by volume of the carbon-based fluorine-containing gas, and wherein the carbon-based fluorine-containing gas is substantially free of sulfur-containing gases. ### Claim 2 (depends on 1) The welding gas mixture of claim 1, wherein the welding gas mixture comprises less than approximately 5 percent by volume of the carbon-based fluorine-containing gas. ### Claim 3 (depends on 1) The welding gas mixture of claim 1, wherein the welding gas mixture comprises less than approximately 2 percent by volume of the carbon-based fluorine-containing gas. ### Claim 4 (depends on 1) The welding gas mixture of claim 1, wherein the carbon-based fluorine-containing gas comprises carbon tetrafluoride. ### Claim 5 (depends on 1) The welding gas mixture of claim 1, wherein the carbon-based fluorine-containing gas comprises any gas having the formula CmFnXp, wherein X is a hydrogen or chlorine atom, m is any value between 1 and 5, n is any value between 1 and 18, and p is any value between 0 and 18. ### Claim 6 (depends on 1) The welding gas mixture of claim 1, wherein the shielding gas comprises argon, helium, carbon dioxide, oxygen, or a combination thereof. ### Claim 7 (depends on 1) The welding gas mixture of claim 1, wherein the welding gas mixture is disposed in a gas cylinder that is coupled to the arc welding system. ### Claim 8 A method of performing an arc welding operation, comprising: controlling a first gas flow of a fluorine-containing gas to an arc welding torch to reduce diffusible hydrogen in a weld pool formed during the arc welding operation, wherein the fluorine-containing gas is a carbon-based fluorine-containing gas; and controlling a second gas flow of a shielding gas to the arc welding torch to control an atmosphere surrounding the weld pool during the arc welding operation. ### Claim 9 (depends on 8) The method of claim 8, wherein the carbon-based fluorine-containing gas comprises any gas having the formula CmFnXp, wherein X is a hydrogen or chlorine atom, m is any value between 1 and 5, n is any value between 1 and 18, and p is any value between 0 and 18. ### Claim 10 (depends on 8) The method of claim 8, wherein the carbon-based fluorine-containing gas comprises carbon tetrafluoride. ### Claim 11 (depends on 8) The method of claim 8, comprising controlling a ratio between the first gas flow and the second gas flow. ### Claim 12 (depends on 8) The method of claim 8, wherein the weld pool is a submerged arc welding (SAW) weld pool and the arc welding torch is a SAW torch. ### Claim 13 (depends on 11) The method of claim 11, comprising mixing the first and second gas flows to produce a gas mixture upstream of the arc welding torch. ### Claim 14 (depends on 12) The method of claim 12, wherein controlling the first gas flow comprises providing the first gas flow to the weld pool from a contact tip of the SAW torch. ### Claim 15 (depends on 13) The method of claim 13, wherein the gas mixture comprises less than approximately 10 percent by volume fluorine-containing gas. ### Claim 16 An arc welding system, comprising: an arc welding torch that forms a weld pool during an arc welding operation; an arc welding gas supply system that supplies a shielding gas flow and a fluorine-containing gas flow to the arc welding torch during the arc welding operation, wherein the shielding gas provides an atmosphere surrounding the weld pool, wherein the fluorine-containing gas reduces diffusible hydrogen in the weld pool, wherein the shielding gas flow is approximately ten times greater than the fluorine-containing gas flow, and wherein the fluorine-containing gas is substantially free of sulfur-containing gases. ### Claim 17 (depends on 16) The arc welding system of claim 16, wherein the fluorine-containing gas comprises carbon tetrafluoride. ### Claim 18 (depends on 16) The arc welding system of claim 16, wherein the arc welding gas supply system comprises a gas premixer that mixes the shielding gas flow with the fluorine-containing gas flow to form a welding gas mixture that is supplied to the arc welding torch of the arc welding system via a single conduit. ### Claim 19 (depends on 16) The arc welding system of claim 16, wherein the arc welding system comprises a submerged arc welding (SAW) system and the arc welding operation comprises a SAW operation. ### Claim 20 (depends on 16) The arc welding system of claim 16, wherein the arc welding torch comprises a first gas conduit that delivers the shielding gas flow to the weld pool and a second gas conduit that separately delivers the fluorine-containing gas flow to the weld pool. ### Claim 21 (depends on 16) The arc welding system of claim 16, wherein the arc welding torch comprises a gas premixer that mixes the shielding gas flow with the fluorine-containing gas flow to form a welding gas mixture that is delivered to the weld pool. ### Claim 22 (depends on 16) The arc welding system of claim 16, wherein the fluorine-containing gas consists essentially of carbon tetrafluoride. ### Claim 23 (depends on 16) The arc welding system of claim 16, wherein the fluorine-containing gas comprises any gas having the formula CmFnXp, wherein X is a hydrogen or chlorine atom, m is any value between 1 and 5, n is any value between 1 and 18, and p is any value between 0 and 18. ### Claim 24 (depends on 16) The arc welding system of claim 16, wherein the shielding gas comprises argon, helium, carbon dioxide, oxygen, or a combination thereof. ### Claim 25 (depends on 16) The arc welding system of claim 16, wherein the shielding gas flow and the fluorine-containing gas flow are mixed within the arc welding torch form a welding gas mixture that comprises less than approximately 2 percent by volume of the fluorine-containing gas. ### Claim 26 A method of performing an arc welding operation, comprising: receiving a shielding gas at a gas premixer of an arc welding system; receiving a fluorine-containing gas at the gas premixer, wherein the fluorine-containing gas is substantially free of sulfur-containing gases; and mixing the shielding gas and the fluorine-containing gas using the gas premixer to generate a welding gas mixture; and delivering the welding gas mixture to a weld pool from an arc welding torch during the arc welding operation, wherein the delivered welding gas mixture comprises less than approximately 10 percent by volume fluorine-containing gas. ### Claim 27 (depends on 26) The method of claim 26, wherein the fluorine-containing gas is a carbon-based fluorine-containing gas. ### Claim 28 (depends on 26) The method of claim 26, wherein the delivered welding gas mixture comprises less than approximately 2 percent by volume fluorine-containing gas. ### Claim 29 (depends on 26) The method of claim 26, wherein the fluorine-containing gas is nitrogen-based, silicon-based, tungsten-based, or a combination thereof. ### Claim 30 (depends on 26) The method of claim 26, wherein the gas premixer is disposed within the arc welding torch. ### Claim 31 A gas cylinder that is coupled to an arc welding system and that contains a welding gas mixture comprising: a shielding gas configured to provide an atmosphere surrounding a weld pool formed by the arc welding system during an arc welding operation; and a fluorine-containing gas configured to reduce diffusible hydrogen in the weld pool, wherein the fluorine-containing gas is a carbon-based fluorine-containing gas that is substantially free of sulfur-containing gases. ### Claim 32 (depends on 31) The gas cylinder of claim 31, wherein the welding gas mixture comprises less than approximately 10 percent by volume fluorine-containing gas. ### Claim 33 (depends on 31) The gas cylinder of claim 31, wherein the gas cylinder is configured to provide the welding gas mixture to the arc welding system during the arc welding operation.