Gas-Shielded Welding Wire Composition for S350EW Weathering Steel

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Solution Overview

Problem

Existing welding wires are not suitable for the third generation of weather-resistant steel S350EW, lacking comprehensive mechanical properties and corrosion resistance matching those of the base material, and do not provide adequate weather resistance and mechanical properties comparable to S350EW.

Innovation Solution

A wire rod for gas shielded welding wire with specific chemical compositions, including C≤0.03%, Mn: 0.20-0.70%, Si: 0.20-0.60%, Ni: 1.6-2.7%, Cr: 1.60-2.20%, Cu: 0.15-0.35%, Ti: 0.01-0.07%, and balanced Fe and impurities, designed to achieve high weather resistance and low strength, ensuring the deposited metal's mechanical properties and corrosion resistance are comparable to S350EW.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If existing welding wires are used for S350EW steel, then welding process is simple, but the deposited metal lacks comprehensive mechanical properties and corrosion resistance matching the base material

Engineering Contradiction:
Improvecorrosion resistanceVSAvoidcompatibility with base material
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent applies parameter changes by precisely controlling the chemical composition parameters of the welding wire. The wire contains C≤0.03%, Si: 0.20-0.60%, Mn: 0.20-0.70%, P≤0.015%, S≤0.015%, Cr: 1.60-2.20%, Ni: 1.6-2.7%, Cu: 0.15-0.35%, and Ti: 0.01-0.07%. This compositional parameter optimization ensures the deposited metal achieves comprehensive mechanical properties and corrosion resistance comparable to S350EW base material, resolving the incompatibility issue.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If welding wire composition is optimized for high corrosion resistance, then weather resistance improves, but mechanical strength may increase beyond ordinary level

Engineering Contradiction:
Improveweather resistanceVSAvoidtensile strength
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent uses parameter changes to balance weather resistance and strength by controlling alloying element contents. Specifically, Cr (1.60-2.20%) and Ni (1.6-2.7%) provide corrosion resistance, while C≤0.03% prevents excessive strength increase. The synergistic composition achieves weather resistance comparable to S350EW while maintaining ordinary-level mechanical properties with tensile strength <650 MPa.

Inventive Principle:
Principle #35Parameter changes

3Strength

If wire rod composition is designed for high strength, then tensile strength increases, but elongation and shaping properties deteriorate

Engineering Contradiction:
Improvetensile strengthVSAvoidshaping property
Core Design Contradiction:
StrengthVSEase of operation

Solution Approach 1:

The patent applies parameter changes by strictly limiting carbon content to C≤0.03% and controlling alloying elements (Si: 0.20-0.60%, Mn: 0.20-0.70%, Cr: 1.60-2.20%, Ni: 1.6-2.7%, Cu: 0.15-0.35%, Ti: 0.01-0.07%). This compositional design prevents excessive strength increase while maintaining good elongation and shaping properties, enabling the wire rod to be easily drawn into welding wire with diameter φ0.8-1.6mm.

Inventive Principle:
Principle #35Parameter changes

4Manufacturing precision

If welding wire achieves comprehensive mechanical properties matching S350EW, then deposited metal quality improves, but welding process adaptability may be reduced

Engineering Contradiction:
Improvedeposited metal qualityVSAvoidwelding process window
Core Design Contradiction:
Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The patent uses parameter changes with a balanced chemical composition (C≤0.03%, Si: 0.20-0.60%, Mn: 0.20-0.70%, P≤0.015%, S≤0.015%, Cr: 1.60-2.20%, Ni: 1.6-2.7%, Cu: 0.15-0.35%, Ti: 0.01-0.07%) that provides both comprehensive mechanical properties and wide welding process adaptability. The moderate alloying content ensures deposited metal quality comparable to S350EW while maintaining sufficient adaptability for various welding conditions.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentUS20240058900A1Wire rod for gas shielded welding wire and welding wire
Publication Date: 2024.02.22 BAOSHAN IRON & STEEL CO LTD

AI summary

The present application discloses a wire rod for gas shielded welding wire, comprising the following chemical elements in mass percentage: C≤0.03%, Mn: 0.20-0.70%, Si: 0.20-0.60%, Ni: 1.6-2.7%, Cr: 1.60-2.20%, Cu: 0.15-0.35%, Ti: 0.01-0.07% and the balance being Fe and inevitable impurities. The present application further discloses a gas shielded welding wire which is made of the above wire rod for gas shielded welding wire. The comprehensive mechanical properties and corrosion resistance of the deposited metal, after the gas shielded welding wire with high weather resistance and low strength is welded, are comparable to those of S350EW (i.e., the welding base material). Moreover, the welding wire has a wide range of processing properties, which can be used for both hot-rolled and cold-rolled sheets