Arc Welding Shielding Sequence for Imaging and Porosity Control
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Solution Overview
Problem
Conventional gas shielded arc welding methods face challenges in preventing specular reflection during photography and suppressing porosity in the welding target material, which can deteriorate mechanical characteristics.
Innovation Solution
A welding method that involves a melting step using arc discharge with an inert gas and an oxidation step where an oxygen-containing gas is supplied to the bonding portion after partial solidification, reducing surface glossiness and preventing porosity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If an inert gas is blown to the surface of a conductor during welding, then the surface is protected from oxidation and maintains glossiness, but specular reflection occurs making it difficult to image the surface and boundary information
Solution Approach 1:
The patent applies periodic action by switching between inert gas supply (during melting) and oxygen-containing gas supply (during oxidation). The inert gas is supplied first to protect the molten pool, then switched to oxygen-containing gas after partial solidification to oxidize the surface and eliminate glossiness, enabling proper imaging while maintaining welding quality.
Solution Approach 2:
The patent changes the chemical composition parameter of the shielding gas from inert (argon) to oxygen-containing (air or oxygen-enriched gas). This parameter change transforms the surface properties from glossy and reflective to matte and non-reflective, solving the imaging problem while maintaining protection against severe oxidation through controlled timing.
2Difficulty of detecting and measuring
If the amount of inert gas is reduced during heating and melting to intentionally oxidize the conductor, then surface glossiness is reduced, but mechanical characteristics are deteriorated due to solidification defects of porosity
Solution Approach 1:
The patent uses periodic action by supplying inert gas during the melting phase to prevent porosity formation, then switching to oxygen-containing gas after partial solidification to oxidize the surface. This timing-based approach ensures that oxidation occurs only after the critical solidification phase, avoiding porosity while achieving the desired surface appearance for imaging.
Solution Approach 2:
The patent applies preliminary action by first establishing a protective inert gas atmosphere during melting to ensure proper solidification without defects, then subsequently introducing oxygen-containing gas after partial solidification has occurred. This sequence ensures that the material structure is stable before oxidation begins, preventing mechanical property deterioration.
3Object-affected harmful factors
If an oxidation promoting gas is blown during welding to cover the welding surface with conductive iron oxide slag, then electrodeposition coating defects are prevented, but the shielding gas is disturbed and voids occur in the welding target material
Solution Approach 1:
The patent applies periodic action by separating the welding and oxidation processes in time. Inert gas is supplied during welding to maintain shielding gas stability and prevent voids, then oxygen-containing gas is supplied after welding completes and partial solidification occurs to create the oxide slag layer. This temporal separation prevents shielding gas disturbance while achieving both welding integrity and coating defect prevention.
Solution Approach 2:
The patent uses preliminary action by completing the welding process with stable inert gas shielding first, ensuring no voids form in the welding target material, then subsequently applying oxygen-containing gas to form the protective oxide slag layer. This sequence ensures that the welding structure is established without defects before oxidation begins.
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
The method effectively prevents specular reflection during photography and suppresses porosity in the welding target material, thereby enhancing the mechanical properties and visibility of the welded surface.
Implementation Method 1
a melting step of melting a bonding portion of a welding target material by arc discharge
Implementation Method 2
while blowing an inert gas to the bonding portion
Implementation Method 3
an oxidation step of oxidizing the bonding portion by supplying the inert gas and a gas containing oxygen to the bonding portion
Data Source
AI summary
Provided is a welding method of preventing specular reflection when a surface of a welding target material is photographed and suppressing an occurrence of porosity of the welding target material.According to the present invention, a welding method includes melting steps (a) and (b) of melting a bonding portion of a welding target material 1 by arc discharge 4 while blowing an inert gas 3 to the bonding portion, and an oxidation step (d) of oxidizing the bonding portion by supplying the inert gas and a gas 6 containing oxygen to the bonding portion in a state where a portion of the melted bonding portion 7 is solidified and the other portion is melted.