Core-Shell Welding Electrode Wire for Tough, Corrosion-Resistant Beads
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Solution Overview
Problem
Welding technologies face challenges in achieving high bead quality with desirable mechanical properties such as yield strength, ductility, corrosion resistance, and fracture toughness while maintaining economic feasibility, as traditional additives like chromium and nickel can be costly and insufficient in addressing competing weldment characteristics.
Innovation Solution
The development of aluminum-containing consumable welding electrode wires with a core-shell structure, where the core comprises aluminum at specific concentrations, and a sheath of steel composition, which when used in welding processes like flux-cored arc welding, produces weld beads with enhanced fracture toughness, corrosion resistance, and resistance to hot cracking at a lower cost compared to traditional additives.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If chromium is added to improve oxidation/corrosion resistance, then corrosion resistance is improved, but cost increases and other properties like fracture toughness may not be sufficiently satisfied
Solution Approach 1:
The patent replaces expensive chromium-based corrosion protection with aluminum, a cheaper metal that forms a protective oxide layer. The aluminum core (3-20 wt% Al) provides corrosion resistance through aluminum oxide formation, significantly reducing material cost while maintaining protective functionality.
Solution Approach 2:
The patent changes the chemical composition parameters by incorporating aluminum at 3-20 wt% and manganese at 1-60 wt% in the core, with specific ranges (3-10 wt% Al and 10-30 wt% Mn) optimizing both corrosion resistance and fracture toughness. This parameter optimization resolves the contradiction between cost and performance.
2Strength
If traditional additives are used to improve weldment properties, then mechanical properties are improved, but economic feasibility deteriorates
Solution Approach 1:
The patent creates a composite wire structure with a steel sheath and aluminum-manganese core. This composite design combines the advantages of steel (strength, weldability) with aluminum (cost-effectiveness, corrosion resistance) and manganese (fracture toughness), achieving high mechanical properties at lower cost than traditional chromium-based alloys.
Solution Approach 2:
The patent substitutes expensive alloying elements (chromium, nickel) with cheaper alternatives (aluminum, manganese) in the core composition, maintaining mechanical property requirements while significantly reducing material costs and improving economic feasibility.
3Strength
If aluminum is added to improve fracture toughness, then fracture toughness is improved, but the composition complexity increases
Solution Approach 1:
The patent applies local quality by concentrating aluminum (3-20 wt%) and manganese (1-60 wt%) specifically in the core region, while the sheath maintains a standard steel composition. This localized alloying achieves high fracture toughness (≥20 ft-lbs at <0°F) without requiring complex composition throughout the entire wire, simplifying manufacturing.
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 aluminum-containing electrode wires achieve high fracture toughness, low porosity, and resistance to hot cracking, while maintaining economic feasibility by balancing competing weldment characteristics and reducing the need for expensive additives, thus improving the overall quality and cost-effectiveness of the welding process.
Implementation Method 1
an electric arc is created when a voltage is applied between a consumable weld electrode wire, which serves as one electrode that advances towards a workpiece, and the workpiece, which serves as another electrode. The arc melts a tip of the metal wire
Implementation Method 2
The arc melts a tip of the metal wire, thereby producing droplets of the molten metal wire
Implementation Method 3
The core comprises aluminum (Al) at a concentration between about 3 weight % and about 20 weight % on the basis of the total weight of the welding wire, where Al is in an elemental form or is alloyed with a different metal element
Data Source
AI summary
The disclosed technology generally relates to consumable electrode wires and more particularly to consumable electrode wires having a core-shell structure, where the core comprises aluminum. In one aspect, a welding wire comprises a sheath having a steel composition and a core surrounded by the sheath. The core comprises aluminum (Al) at a concentration between about 3 weight % and about 20 weight % on the basis of the total weight of the welding wire, where Al is in an elemental form or is alloyed with a different metal element. The disclosed technology also relates to welding methods and systems adapted for using the aluminum-comprising electrode wires.