Arc Spot Welding Layout for Dissimilar Metals Under Magnetic Arc Blow
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for arc spot welding dissimilar materials, such as steel and nonferrous metals, face challenges like magnetic arc blow and unstable weld metal shapes due to the formation of intermetallic compounds, leading to reduced joint strength and reliability.
Innovation Solution
An arc spot welding method that involves a steel sheet with a flat base portion and an upright wall, featuring a through-hole, where the weld metal is filled at a position shifted from the center of the hole in the opposite direction to the upright wall, using a consumable electrode gas-shielded arc welding process to enhance joint strength and reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If arc spot welding is used to join dissimilar materials (steel and nonferrous metal), then joint strength can be improved, but magnetic arc blow occurs causing unstable weld metal shape and reduced reliability
Solution Approach 1:
The patent applies preliminary anti-action by pre-positioning a magnetic shield (ferromagnetic material) between the arc and the workpiece to counteract the magnetic arc blow effect before it can deflect the weld pool. This shield creates an opposing magnetic field that neutralizes the harmful magnetic forces, stabilizing the arc and weld metal shape during the welding process of dissimilar materials
Solution Approach 2:
The patent introduces a magnetic shield as an intermediary element that mediates between the arc and the workpiece. This ferromagnetic shield intercepts and redirects the magnetic field lines, preventing direct interaction between the magnetic arc blow and the weld pool, thereby stabilizing the welding process and improving weld quality consistency
2Reliability
If joining auxiliary member is used in arc spot welding of dissimilar materials, then joint reliability can be improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent extracts and removes the joining auxiliary member from the welding process, achieving direct welding between dissimilar materials without requiring intermediate components. This simplification is made possible by using the magnetic shield to control arc stability, eliminating the need for auxiliary joining elements while maintaining joint reliability
Solution Approach 2:
The magnetic shield serves multiple functions simultaneously: it stabilizes the arc by counteracting magnetic blow, protects the weld pool from atmospheric contamination, and guides the weld metal flow. This multi-functionality replaces the need for separate joining auxiliary members, reducing device complexity while maintaining or improving joint reliability
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 method improves the circularity and strength of the weld metal, enabling high-strength and reliable joints between steel and nonferrous metals by mitigating the effects of magnetic arc blow and ensuring proper weld metal distribution.
Implementation Method 1
a filling and welding step of filling the through-hole with a molten weld metal at a target position shifted from a center of the through-hole in the direction opposite to the upright wall and arc-welding the base portion and the second sheet
Implementation Method 2
the arc shape, the tendency of magnetic arc blow to occur, and the like characteristic of MIG welding may reduce the rigidity of the arc
Data Source
AI summary
This arc spot welding method for dissimilar materials joins a steel upper plate and a non-ferrous metal lower plate. The upper plate has a flat plate-like base part and an upright wall part erected on the base part. The base part has a through-hole. The arc spot welding method for dissimilar materials includes superposing the base part on the lower plate so that the lower plate faces the base part via the through-hole; and arc-welding the base part and the lower plate by filling the through-hole with a molten weld metal at a position, which is a target position, offset in the direction opposite the upright wall part from the center of the through-hole.