Arc Welding Wire Composition for Low-Spatter High-CO2 Welding

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Solution Overview

Problem

Existing arc welding methods fail to adequately address spatter generation and electrodeposition coating properties, particularly when using high CO2 shielding gases, leading to incomplete rust prevention films on complex weld shapes and increased operator burden.

Innovation Solution

An arc welding method that alternates forward and backward feeding of welding wire, controlling chemical components within specified ranges, and using a high CO2 shielding gas to reduce spatter and improve electrodeposition coating properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a shielding gas containing high CO2 content (80 vol.% or more) is used, then welding cost is reduced and welding speed is improved, but spatter generation increases and electrodeposition coating quality deteriorates

Engineering Contradiction:
Improvewelding speedVSAvoidspatter generation
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The invention changes the chemical composition parameters of the welding wire by precisely controlling the content ratios of Si (0.01-0.30 mass%), Ti (0.05-0.30 mass%), S (0.001-0.020 mass%), and other elements. This parameter optimization modifies the slag properties to reduce spatter generation while maintaining good electrodeposition coating characteristics, even when using high CO2 shielding gas

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If Si content in welding wire is reduced to decrease slag thickness, then electrodeposition coating property is improved, but molten wire viscosity decreases and droplet transfer stability deteriorates

Engineering Contradiction:
Improveelectrodeposition coating qualityVSAvoiddroplet transfer stability
Core Design Contradiction:
Manufacturing precisionVSStability of the object's composition

Solution Approach 1:

The invention uses a composite approach by combining multiple elements (Si, Ti, S, Mn, Al, etc.) in specific proportions to create a balanced welding wire composition. The synergistic interaction between these elements achieves both thin slag formation for good coating quality and appropriate viscosity for stable droplet transfer

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The invention optimizes the chemical composition parameters within specific ranges: Si (0.01-0.30 mass%), Ti (0.05-0.30 mass%), S (0.001-0.020 mass%), and controls the ratio 2×[Ti]/[Si]−50×[S] > 1.0. These parameter changes balance slag thickness and molten wire viscosity to simultaneously achieve good coating quality and droplet transfer stability

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If mechanical method is used to remove slag from bead surface, then electrodeposition coating quality is improved, but operator burden increases and productivity decreases

Engineering Contradiction:
Improveelectrodeposition coating qualityVSAvoidproduction efficiency
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The invention makes the welding process self-service by optimizing wire composition to naturally produce slag with properties that facilitate automatic removal or easy detachment during cooling. The controlled slag composition (thin, non-scattered) allows the bead surface to be automatically prepared for coating without requiring separate mechanical cleaning operations

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The invention extracts the slag removal function from the post-welding process by designing the welding parameters and wire composition to produce slag that separates easily from the bead surface during or immediately after welding, eliminating the need for separate mechanical removal steps

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

Reduces spatter generation and enhances electrodeposition coating on welds, ensuring effective rust prevention even with high CO2 shielding gases, particularly on complex shapes.

Implementation Method 1

arc welding method

Methodology Applied
Scientific EffectElectric arc: Electric Arc

Implementation Method 2

shielding gas containing CO2 gas in an amount of 80 vol. % or more

Methodology Applied
Scientific EffectShielding gas protection:

Implementation Method 3

slag generated on a weld bead... thick slag containing Si as a main component

Methodology Applied
Scientific EffectOxidation: Oxidation

Implementation Method 4

electrodeposition coating technique or the like for applying a coating film for rust prevention after welding

Methodology Applied
Scientific EffectElectrodeposition: Electrodeposition

Data Source

PatentUS12605793B2Arc welding method
Publication Date: 2026.04.21 KOBE STEEL LTD

AI summary

An arc welding method includes welding a steel sheet while alternately switching feeding of a welding wire between forward feeding and backward feeding. The welding wire contains, in mass % with respect to a total mass to the welding wire, C: more than 0 and 0.30 or less, Si: 0.01 to 0.30, Mn: 0.5 to 2.5, S: 0.001 to 0.020, Ti: 0.05 to 0.30, and optional elements with the remainder being Fe and unavoidable impurities, and a value obtained by 2×[Ti]/[Si]−50×[S] is more than 1.0. The welding is performed by using a shielding gas containing CO2 gas in an amount of 80 vol. % or more with respect to a total volume of the shielding gas at a frequency of 40 Hz or more and 200 Hz or less, where one cycle for determining the frequency is one forward feeding and one backward feeding.