Welding Torch Suction Nozzle for Hydrogen Crack Prevention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The welding industry faces challenges with hydrogen embrittlement and hydrogen cracking in weld metals due to diffusible hydrogen, particularly in high-strength steels, where existing methods like preheating, post-heating, and adding fluorides to the flux can be energy-intensive and affect arc stability.
Innovation Solution
A welding method and device that uses a suction nozzle to extract hydrogen-rich gases from the arc column and its periphery, mixing them with new shielding gas to reduce diffusible hydrogen in the weld metal, while allowing the welding wire to be a flux cored wire containing fluoride.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If preheating or post-heating is performed to reduce diffusible hydrogen, then hydrogen embrittlement and cracking are prevented, but energy consumption increases and working conditions deteriorate
Solution Approach 1:
The invention extracts hydrogen sources from the wire surface and vaporizes them in the wire protruding section before the wire reaches the arc. This preliminary removal of hydrogen sources prevents hydrogen from entering the weld metal, eliminating the need for post-weld heating treatments while reducing energy consumption.
Solution Approach 2:
The invention extracts hydrogen-containing substances (oil, moisture, flux components) from the wire surface and interior by heating the wire protruding section. This extraction removes the harmful hydrogen sources before welding, preventing hydrogen embrittlement without requiring additional heating of the workpiece.
2Reliability
If fluoride is added to the flux to reduce diffusible hydrogen, then hydrogen cracking is prevented, but arc stability deteriorates
Solution Approach 1:
The invention extracts and removes hydrogen sources from the flux and wire surface through heating the wire protruding section. By removing hydrogen sources externally before welding, the invention eliminates the need to add fluoride to the flux, thereby maintaining arc stability while preventing hydrogen cracking.
3Quantity of substance
If hydrogen sources are vaporized in the wire protruding section, then diffusible hydrogen is reduced, but hydrogen sources may still be carried into the arc column
Solution Approach 1:
The invention introduces a suction device as an intermediary between the wire protruding section and the arc column. This suction device extracts vaporized hydrogen sources and shielding gas from the wire protruding section, preventing them from being carried into the arc column by the shielding gas flow, thereby ensuring complete hydrogen removal.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach effectively reduces the amount of diffusible hydrogen in weld metal, preventing embrittlement and cracking, and lowers the required preheating temperatures, thus reducing energy costs and improving working conditions for welders.
Implementation Method 1
sucking gas containing hydrogen source discharged from a welding wire, from an arc column and a periphery of the arc column, by using a suction nozzle
Implementation Method 2
the wire 201 is melted by an arc 209 at a tip of the wire 201
Implementation Method 3
hydrogen sources 205 of a surface of the wire 201 are first vaporized to be discharged from the wire 201
Implementation Method 4
the hydrogen sources 205, for example, H2O, are dissociated to become diffusible hydrogen 212
Implementation Method 5
the hydrogen sources 205 discharged from the wire 201 flows in the direction illustrated by the arrows 213 to be guided to the arc 209 by a flow of shielding gas supplied from a nozzle 206
Implementation Method 6
the central part 203 is heated by heat conduction from the heated steel hoop 202
Data Source
AI summary
A welding system includes a welding torch that welds a workpiece by using a wire, a suction device that sucks shielding gas, and a sucked shielding gas supply path for allowing the sucked shielding gas to flow, wherein the welding torch includes a contact chip that guides the wire, a shielding gas supply nozzle that supplies the shielding gas to a weld zone, and a suction nozzle that surrounds a periphery of the wire protruding from the contact chip, and is opened toward a tip of the wire to suck the shielding gas.