Gas-Shielded Arc Welding Wire Composition for Slag-Free Coating
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Solution Overview
Problem
Current welding wires for gas-shielded arc welding generate excessive spatter and require a separate slag removal step, leading to coating defects and reduced corrosion resistance, especially in thin steel sheets used in vehicle underbody parts.
Innovation Solution
A wire composition with specific ranges of C, Si, Mn, Ti, Cu, S, N, Al, and P, along with controlled ratios, is used to minimize spatter generation and form a thin, adhesive slag that allows for uniform electrodeposition coating without post-weld slag removal, enhancing bead shape and corrosion resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional welding wire is used, then welding can be performed, but excessive spatter is generated and slag removal step is required
Solution Approach 1:
The patent applies parameter changes by precisely controlling the chemical composition parameters of the welding wire (C: 0.01-0.10%, Si: 0.05-0.55%, Mn: 1.60-2.40%, Ti: 0.05-0.25%, Cu: 0.01-0.30%, S: 0.001-0.020%, N: 0.0045-0.0150%, Al: 0.10%, P: 0.025%) and the ratio between Si and Ti (0.1<[Si]/[Ti]≤3.0). This compositional parameter optimization enables the wire to form slag with appropriate viscosity and adhesion properties, eliminating the need for separate slag removal operations while reducing spatter generation.
2Reliability
If electrodeposition coating is performed after welding, then corrosion protection is improved, but coating film does not form on weld slag resulting in coating defects
Solution Approach 1:
The patent modifies the chemical composition parameters of the welding wire to control slag formation characteristics. By adjusting Si content (0.05-0.55%) and Ti content (0.05-0.25%) with controlled ratio (0.1<[Si]/[Ti]≤3.0), the slag achieves optimal viscosity and surface properties that enable uniform electrodeposition coating formation, eliminating coating defects while maintaining corrosion protection.
3Manufacturing precision
If electrodeposition coating film thickness is increased to prevent coating defects, then coating coverage is improved, but coating film peels off with slag during traveling
Solution Approach 1:
The patent optimizes the slag-forming element parameters (Si: 0.05-0.55%, Ti: 0.05-0.25%, Mn: 1.60-2.40%) and their ratios to control slag viscosity and adhesion properties. This enables the formation of a thin coating film that adheres strongly to the base metal while the slag peels off easily, preventing coating film detachment during subsequent handling and traveling.
4Reliability
If galvanized steel sheet is used for sacrificial anticorrosion effect, then corrosion resistance is improved, but zinc is vaporized by arc welding heat reducing effectiveness
Solution Approach 1:
The patent extracts the corrosion protection function from the galvanized coating and transfers it to the weld slag layer. By optimizing the welding wire composition (particularly Si: 0.05-0.55% and Ti: 0.05-0.25%), the slag forms a protective layer on the weld bead that provides corrosion resistance without requiring zinc coating, thereby avoiding zinc vaporization during welding.
5Weight of moving object
If thin steel sheet is used to reduce vehicle weight, then weight reduction is achieved, but corrosion resistance and durability of underbody parts deteriorate
Solution Approach 1:
The patent converts the potential harm of thin steel sheet usage (reduced corrosion resistance) into a benefit by optimizing the welding process. The controlled slag formation (through Si: 0.05-0.55% and Ti: 0.05-0.25% with ratio 0.1<[Si]/[Ti]≤3.0) creates a protective layer on the weld bead that enhances corrosion resistance, allowing thin steel sheets to maintain both weight reduction and durability.
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 solution reduces spatter, eliminates the need for slag removal, and achieves excellent electrodeposition coatability and rust prevention, improving the durability and fatigue resistance of welds in thin steel sheets.
Implementation Method 1
a method of electrodeposition coating after arc welding is adopted as a method of protecting underbody parts from a corrosive environment
Implementation Method 2
Wire for gas-shielded arc welding
Implementation Method 3
zinc is vaporized in the weld portion by heat during arc welding
Data Source
AI summary
A wire for gas-shielded arc welding includes, based on a total mass of the wire: C: 0.01 mass % or more and 0.10 mass % or less, Si: 0.05 mass % or more and 0.55 mass % or less, Mn: 1.60 mass % or more and 2.40 mass % or less, Ti: 0.05 mass % or more and 0.25 mass % or less, Cu: 0.01 mass % or more and 0.30 mass % or less, S: 0.001 mass % or more and 0.020 mass % or less, N: 0.0045 mass % or more and 0.0150 mass % or less, Al: 0.10 mass % or less, and P: 0.025 mass % or less, with the remainder being Fe and inevitable impurities. In the wire, the following relationship is satisfied: 0.1≤[Ti]/[Si]≤3.0, where [Si] is the content of Si (mass %) and [Ti] is the content of Ti (mass %).