Solid-Core Welding Wire with Insulating Intermediate Layer

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing arc welding wires face limitations in welding speed, deposition rate, weldability, and energy requirements, leading to potential deformations in the materials being welded, particularly with solid wires that cannot enhance arc ionization or mechanical properties.

Innovation Solution

A welding wire design featuring a solid metal core surrounded by an intermediate insulating layer and an outer metal casing, where the intermediate layer contains specific compounds to modify arc ionization and metallurgy, and the outer casing is made of steel, allowing for improved energy efficiency and weld quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If solid wire is used for welding, then the structure is simple and easy to manufacture, but the welding speed and deposition rate are limited and energy requirements increase

Engineering Contradiction:
Improvewelding speed and deposition rateVSAvoidenergy requirements
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The welding wire is segmented into three distinct functional layers: a solid metal core for structural integrity and metal deposition, an intermediate insulating layer to concentrate current, and an outer conductive casing for current delivery. This segmentation allows each layer to optimize its specific function, resolving the contradiction by enabling higher deposition rates through focused energy delivery while maintaining manufacturing simplicity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The welding wire employs a composite structure combining three different material types with distinct properties: conductive metal (core and casing) for electrical function and metal deposition, and insulating material (intermediate layer) for current concentration. This composite design enables simultaneous achievement of high welding speed, high deposition rate, and reduced energy requirements by optimizing the function of each material component.

Inventive Principle:
Principle #40Composite materials

2Reliability

If solid wire is used, then manufacturing is simple, but arc ionization and mechanical properties cannot be improved through microalloys

Engineering Contradiction:
Improvearc ionization and mechanical propertiesVSAvoidwire structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Different regions of the wire are assigned different properties: the core provides structural integrity, the intermediate layer provides insulation and current concentration, and the outer casing provides conductivity and surface quality for arc initiation. This local differentiation of properties enables improved arc ionization and mechanical characteristics without requiring complex overall structure, as each local region is optimized for its specific function.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The intermediate insulating layer acts as a mediator between the solid metal core and the outer conductive casing. This intermediate layer enables current concentration and improved arc ionization by directing electrical current through a focused path, while also protecting the core from oxidation. The intermediary layer resolves the contradiction by enabling advanced electrical properties without requiring the entire wire structure to be complex.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If high energy is applied to increase welding speed, then productivity improves, but material deformation increases

Engineering Contradiction:
Improvewelding speedVSAvoidmaterial deformation
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The harmful dispersion of energy into surrounding materials is extracted and eliminated through the insulating intermediate layer, which confines and directs electrical current through a focused path. This extraction of energy dispersion enables high welding speed through concentrated energy delivery while preventing the energy from causing deformation in surrounding materials, thus resolving the contradiction between productivity and material integrity.

Inventive Principle:
Principle #2Taking out (Extraction)

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 design enhances welding speed and deposition rate, reduces energy requirements, and minimizes material deformation by concentrating welding current in the outer casing, while enabling controlled modification of the weld joint's chemistry and protecting the internal wire from oxidation.

Implementation Method 1

an intermediate layer between the central core and the outer tubular metal casing containing one or more compounds... the intermediate layer is electrically insulating, that is to say it contains one or more electrically insulating elements or compounds and/or having a high electrical resistivity

Methodology Applied
Scientific EffectElectrical insulation: Electrical Resistance

Implementation Method 2

Certain welding processes, in particular electric arc welding, for example in MIG/MAG welding or in submerged arc welding, require the use of one (or more) welding wire which is gradually melted by one (or more) electric arc

Methodology Applied
Scientific EffectElectric arc: Electric Arc

Implementation Method 3

gradually melted by one (or more) electric arc

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Data Source

PatentEP2666580B1Solid-core welding wire and method for manufacturing same
Publication Date: 2020.07.29 LINCOLN ELECTRIC ITALA SRL
  • EP2666580B1 patent drawingFigure 1
  • EP2666580B1 patent drawingFigure 2A~3

AI summary

The welding wire (1) comprises a central core (4) formed of a solid wire, an external tubular metal envelope (2) forming a sleeve around the solid wire, and an intermediate layer (3) that is formed between the central core and the external tubular metal envelope, and contains compounds. The intermediate layer is electrically insulating, and has an electrical resistance higher than that of the tubular metal envelope. The solid wire represents 50-95% of a sectional surface of the welding wire. The intermediate layer represents 0.0001-20% of the sectional surface of the welding wire. The solid-core welding wire (1) comprises a central core (4) formed of a solid wire, an external tubular metal envelope (2) forming a sleeve around the solid wire, and an intermediate layer (3) that is formed between the central core and the external tubular metal envelope, and contains compounds. The intermediate layer is electrically insulating, and has an electrical resistance higher than that of the tubular metal envelope. The solid wire represents 50-95% of a sectional surface of the welding wire. The intermediate layer represents 0.0001-20% of the sectional surface of the welding wire. The external tubular metal envelope represents the remainder of the sectional surface of the welding wire. The external tubular metal envelope presents a surface treated by standard coppering or bronzing. The welding wire has an external diameter of 0.8-5 mm. An independent claim is included for a method for manufacturing a solid-core welding wire.