Metal-Based Flux Cored Wire for Ar-CO2 Welding

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Solution Overview

Problem

Conventional metal-based flux cored wires for Ar-CO2 mixed gas shielded arc welding result in excessive slag and spatter formation, unstable arcs, and poor low-temperature toughness during short and spray arc welding, limiting their efficiency and quality in applications like construction machinery and steel frames.

Innovation Solution

A metal-based flux cored wire with a steel sheath filled with flux containing 97% or more metal powder, specific compositions of C, Si, Mn, S, and iron powder with low oxygen content, and limited alkali metal oxides and fluorides, along with optional Ni and B, to minimize slag and spatter formation and enhance arc stability and low-temperature toughness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional metal-based flux cored wire with high metal powder content is used for Ar-CO2 mixed gas shielded arc welding, then welding efficiency and weldability are improved, but slag and spatter formation increases excessively

Engineering Contradiction:
Improvewelding efficiencyVSAvoidslag and spatter formation
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent applies parameter changes by precisely controlling the chemical composition parameters of the flux, including limiting total slag-forming agents to 3.0-8.0 mass%, alkali metal oxides/fluorides to 0.05-0.50 mass%, and metal oxides to 0.10-1.00 mass%. This optimization resolves the contradiction by maintaining high metal powder content (92-99 mass%) for welding efficiency while constraining slag-forming parameters to minimize harmful formation.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses composite materials by formulating a complex flux composition that combines multiple components in specific proportions: iron powder (4.0-20.0 mass%), steel powder (5.0-20.0 mass%), aluminum powder (0.1-5.0 mass%), silicon powder (0.1-5.0 mass%), manganese powder (0.1-5.0 mass%), and controlled amounts of slag-forming agents. This composite approach allows simultaneous achievement of high weldability and reduced slag/spatter.

Inventive Principle:
Principle #40Composite materials

2Reliability

If conventional flux cored wire is used for short arc welding, then low current region weldability is improved, but droplet spatter occurrence increases

Engineering Contradiction:
Improvelow current region weldabilityVSAvoiddroplet spatter
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent applies parameter changes by optimizing the flux composition parameters specifically for short arc welding conditions, including controlling iron powder content (4.0-20.0 mass%) and aluminum powder (0.1-5.0 mass%) to regulate droplet transfer characteristics. The controlled slag-forming agents (3.0-8.0 mass%) create a protective environment that reduces spatter while maintaining weldability in low current regions.

Inventive Principle:
Principle #35Parameter changes

3Speed

If conventional flux cored wire is used for spray arc welding, then welding speed is improved, but arc stability deteriorates and spatter increases

Engineering Contradiction:
Improvewelding speedVSAvoidarc stability
Core Design Contradiction:
SpeedVSStability of the object's composition

Solution Approach 1:

The patent applies parameter changes by precisely controlling the flux composition parameters including alkali metal oxides/fluorides (0.05-0.50 mass%) and metal oxides (0.10-1.00 mass%) to stabilize the arc during spray arc welding. The optimized metal powder content (92-99 mass%) and controlled slag-forming agents maintain arc stability while enabling high welding speed operation.

Inventive Principle:
Principle #35Parameter changes

4Reliability

If conventional flux cored wire with high slag-forming agents is used, then weldability is improved, but low temperature toughness of weld metal deteriorates

Engineering Contradiction:
ImproveweldabilityVSAvoidlow temperature toughness
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent applies parameter changes by strictly limiting the parameters of slag-forming agents (total: 3.0-8.0 mass%, metal oxides: 0.10-1.00 mass%) to prevent excessive oxygen in the weld metal. This parameter optimization maintains adequate weldability while preserving low temperature toughness by controlling the chemical composition to minimize harmful inclusions.

Inventive Principle:
Principle #35Parameter changes

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 significantly reduces slag and spatter formation, achieves stable arc conditions, and improves the low-temperature toughness of weld metal, resulting in high-quality weldments with enhanced efficiency in multipass welding and low-temperature applications.

Implementation Method 1

Ar-CO2 mixed gas shielded arc welding

Methodology Applied
Scientific EffectElectric arc: Electric Arc

Implementation Method 2

arc welding

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 3

Mn, Si, other alloy agents and deoxidizing agents

Methodology Applied
Scientific EffectDeoxidation: Reduction

Data Source

PatentEP2105243B1Metal-based flux cored wire for Ar-CO2 mixed gas shielded arc welding
Publication Date: 2011.01.05 NIPPON STEEL & SUMIKIN WELDING CO LTD

AI summary

A metal-based flux cored wire for Ar-CO2 mixed gas shielded arc welding used for short arc welding and spray arc welding, resulting in extremely small amount of formation of slag and amount of occurrence of spatter, giving a good bead shape, and giving excellent low temperature toughness of the weld metal, in particular a flux cored wire comprising a steel sheath in which a flux is filled ,characterized in that the flux contains a metal powder in 97 mass% or more, and the wire contains , by mass% with respect to the total weight of the wire, C: 0.03 to 0.12%, Si: 0.5 to 1.2%, Mn: 1.5 to 3.5%, S: 0.005 to 0.05%, iron powder with amount of oxygen of 0.25% or less: 4.0 to 15.5%, a total of one or more of alkali metal oxides, alkali metal fluorides, and metal oxides: 0.35% or less, and the balance of mainly Fe ingredient of the steel sheath and Fe ingredients from the flux etc. and unavoidable impurities.