Plated Steel Weld Joint Geometry for Low Porosity and Fatigue Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Welded members for plated steel plates face challenges in porosity resistance and fatigue properties due to stress concentration at weld joints and the sensitivity of high-strength steel materials to pore defects during arc welding, which reduces the durability and corrosion resistance of automotive chassis components.
Innovation Solution
A welded member with a toe angle of 45° or less, formed by arc welding plated steel plates using a pulse current with a specific wave frequency and shielding gas composition, including Ar with 10-30% CO2, to minimize pore defects and enhance fatigue strength, achieving a pore area ratio less than 0.5% and fatigue life of 2,000,000 cycles or more under cyclic load.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If high-strength steel materials are used for weight reduction, then the strength and weight reduction goals are achieved, but the material becomes more sensitive to pore defects during arc welding, reducing fatigue properties
Solution Approach 1:
The patent applies parameter changes by optimizing the protective gas composition (specific ratios of Ar, CO2, and O2) and welding current parameters to control the welding process. This resolves the contradiction by creating welding conditions that minimize pore formation in high-strength plated steel, thereby maintaining both strength and fatigue properties
Solution Approach 2:
The patent converts the harmful effect of plated steel sensitivity to pore defects into a benefit by developing a specialized welding method that not only prevents pores but also creates an enhanced weld structure. The controlled welding parameters transform the potential vulnerability of plated steel into an opportunity for achieving superior weld quality with excellent fatigue resistance
2Strength
If arc welding is performed on plated steel plates, then the assembly strength is secured, but pore defects such as pits or blow holes occur, reducing weld strength and fatigue properties
Solution Approach 1:
The patent uses an inert and active gas mixture (Ar with controlled CO2 and O2) to create a protective atmosphere during welding. This prevents pore defects by controlling the chemical environment, allowing arc welding to proceed without generating pits or blow holes while maintaining weld strength
Solution Approach 2:
The patent optimizes specific welding parameters including current amplitude, pulse width, and gas flow rates to prevent pore formation. These parameter adjustments ensure that arc welding produces high-quality welds on plated steel without generating harmful pore defects
3Reliability
If the toe angle of the weld joint is reduced to improve fatigue properties, then the stress concentration is reduced, but the welding process becomes more complex to control
Solution Approach 1:
The patent employs periodic pulse current with specific amplitude and width parameters to control the welding process. This periodic action automatically achieves the desired toe angle geometry and minimizes stress concentration, improving fatigue properties while keeping the control system manageable through automated pulse regulation
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 effectively reduces pore defects and stress concentration, improving the fatigue properties and corrosion resistance of welded members, enabling the use of high-strength plated steel for lightweight automotive components with enhanced durability and rust prevention.
Implementation Method 1
a weld metal portion formed by arc welding
Implementation Method 2
supplying a welding current to a solid wire to generate an arc, wherein the welding current is a pulse current repeated with a first peak and a second peak having a current value smaller than the first peak as one pulse period, and a welding molten metal stirring wave frequency
Data Source
AI summary
Disclosed is a welded member for plated steel plate having excellent weld zone porosity resistance and fatigue properties and a method of manufacturing the same. The welded member for plated steel plate having excellent weld zone porosity resistance and fatigue properties according to an embodiment of the present invention comprises a weld metal portion formed by arc welding and overlapping a first member and a laminated second member so as to partially overlap the first member, wherein the toe angle (θ) of the weld metal portion is 45° or less, and the first member and the second member are plated steel plates.