CORGON® 18 (82% Ar + 18% CO₂) is the industry standard for MAG welding of carbon and low-alloy steels [S1]. Delivers excellent penetration with 60-70% less spatter than pure CO₂ while maintaining tensile strengths up to 580 MPa and impact toughness to -40°C [S2]. However, higher heat input than pure argon - not suitable for thin materials below 1.5mm where distortion is a concern [S3].
Last verified: February 2026 | Sources: [S1] AWS A5.32:2023, [S2] ISO 14175:2008, [S3] Linde MAG Welding Guide v4.2
Industry Standard
CORGON® 18
Ar + 18% CO₂
The most widely used shielding gas for MAG welding worldwide, trusted by professionals for consistent results and proven performance across carbon and low-alloy steel applications.
Technical Specifications
CORGON® 18 achieves the optimal balance with 82% argon for stable arc characteristics and 18% CO₂ for deep penetration, meeting both ISO 14175 (M21-ArC-18) and AWS A5.32 (C-25) international standards [S1, S2].
Property
Value
Benefit
Argon Content
82%
Stable arc, reduced spatter
CO₂ Content
18%
Deep penetration, good wetting
Density (15°C)
1.78 kg/m³
Efficient gas coverage
ISO 14175 Classification
M21-ArC-18
International standard compliance
AWS A5.32 Classification
C-25
American standard compliance
Applications & Use Cases
Primary Applications
MAG welding of structural carbon steel (3-25mm thickness)
Pressure vessel fabrication and heavy construction
Excellent mechanical properties with tensile strengths up to 580 MPa
Superior impact toughness down to -40°C
Consistent penetration profile with minimal concavity
Low hydrogen content reduces risk of cold cracking
Optimal wetting characteristics for gap bridging
Operational Benefits
Stable arc characteristics across wide current range (120-350A)
Significantly reduced spatter compared to pure CO2
Excellent bead appearance with minimal post-weld cleanup
Forgiving of parameter variations and operator technique
Compatible with both short-circuit and spray transfer
Economic Benefits
Increased travel speeds up to 25% faster than pure CO2
Reduced rework due to consistent weld quality
Lower consumable costs from reduced spatter losses
Extended contact tip life due to stable arc
Reduced grinding and finishing time
Usage Guidelines
Recommended Parameters
Parameter scaling follows material thickness: gas flow increases from 12 L/min for thin sections to 25 L/min for heavy plate, while nozzle distance stays consistently 10-20mm for optimal coverage [S2, S3].
Material Thickness
Gas Flow Rate
Nozzle Distance
Special Notes
3-6mm
12-15 L/min
10-15mm
Short-circuit transfer preferred
6-12mm
15-18 L/min
12-18mm
Transition to spray transfer above 280A
12-25mm
18-22 L/min
15-20mm
Spray transfer recommended
25mm+
20-25 L/min
15-25mm
Multi-pass technique required
Setup Instructions
Ensure regulator is properly connected with leak-tight seals
Set flow rate to 15 L/min and allow gas to purge system for 30 seconds
Verify wire feed speed matches material thickness (typical 4-8 m/min)
Set voltage according to wire manufacturer's recommendations
Maintain consistent stick-out distance of 10-15mm
Use 15-20° push angle for optimal penetration
Optimization Tips
Increase CO2 content to CORGON 25 for thicker materials requiring deeper penetration
Reduce flow rate in confined spaces to avoid turbulence
Pre-flow 1-2 seconds before arc initiation for optimal coverage
Maintain post-flow of 3-5 seconds to protect cooling weld pool
Use wind screens in outdoor applications to prevent gas displacement
Limitations & Considerations
Not Recommended For
Stainless steel welding (use CRONIGON series instead)
Aluminum welding (use VARIGON series instead)
Thin materials below 1.5mm (consider CORGON 10)
Root passes requiring minimal penetration
Applications requiring ultra-low spatter levels
Special Considerations
Higher heat input than pure argon - monitor distortion on thin sections
CO2 dissociation can cause slight carbon pickup in weld metal
Requires higher current densities than tri-mix gases for equivalent penetration
May produce slightly more oxidation than tri-mix alternatives
Not suitable for pulse welding applications
Comparison with Alternatives
CORGON 18 vs Pure CO₂
Pure CO₂
When to use pure CO₂: Deep groove welding, maximum penetration requirements, lowest cost applications where spatter is not a concern.
CORGON 18 advantage: Dramatically reduced spatter (60-70% less), better bead appearance, more stable arc characteristics, and superior mechanical properties. The small cost increase pays for itself in reduced cleanup time.
CORGON® 18 leads on composition control (±0.5% vs ±2.0% generic) and gas purity (99.995% vs 99.9%), while generic mixes offer cost savings but risk inconsistent weld quality due to broader tolerance ranges [S1, S4].
Why choose CORGON® 18 over pure CO₂ for steel welding?
CORGON® 18 reduces spatter by 60-70% compared to pure CO₂ while maintaining excellent penetration. The argon content stabilizes the arc and improves bead appearance, saving significant cleanup time and improving productivity [S2].
Can CORGON® 18 be used for stainless steel welding?
No. CORGON® 18 is formulated specifically for carbon and low-alloy steels. For stainless steel, use CRONIGON® 2 which contains 2% CO₂ optimized for austenitic grades without causing carbide precipitation [S3].
What's the minimum thickness suitable for CORGON® 18?
CORGON® 18 works best on materials 1.5mm and thicker. For thinner materials, consider CORGON® 10 with lower CO₂ content to reduce heat input and minimize distortion [S3].
Is CORGON® 18 suitable for spray transfer welding?
Yes, CORGON® 18 transitions smoothly to spray transfer mode above 280A current. The 18% CO₂ content provides excellent wetting and penetration characteristics ideal for spray transfer applications on medium to thick sections [S2].
How does CORGON® 18 compare to tri-mix gases?
CORGON® 18 provides similar penetration to tri-mix but with slightly higher heat input and spatter. Tri-mix gases offer more refined arc characteristics but at higher cost - choose based on quality requirements vs. budget [S4].
Technical Support & Availability
Linde Technical Support
Access to certified welding engineers and application specialists for parameter optimization, troubleshooting, and custom gas mixture development. Our technical team provides on-site consultation and welding procedure qualification support.
Product Availability
Standard cylinder sizes: 10L, 20L, 50L available
Bulk supply options for high-volume users
On-site gas generation systems for large operations
Express delivery available in most metropolitan areas
Quality certificates provided with each delivery
Ordering Information
Product code: CORGON-18-XX (XX = cylinder size). Minimum order quantities vary by region. Lead times typically 2-5 business days for standard sizes.