Magnesium Anode (Circular Type)

Description

Magnesium anodes serve as a popular solution to combat corrosion in situations where applying impressed current cathodic protection isn’t practical or viable for the specific infrastructure.

For soil applications, naked magnesium anodes are widely favored. Their pronounced negative potential generates a robust driving force, enabling them to effectively shield subterranean steel structures in soils with moderate to high resistivity levels (1,000 – 10,000 Ω·cm).

Our naked magnesium anodes are typically crafted into two variants with distinct electrode potentials compared to a Cu/CuSO4 reference electrode. These variations cater to a broad spectrum of buried metallic structures across different soil resistivities. The high-potential magnesium anodes excel in arid or resistant earth conditions or situations necessitating heightened current due to poorly coated tanks. Conversely, the standard-potential magnesium anodes demonstrate remarkable performance in corrosive soils, especially when tanks are adequately coated, ensuring a longer lifespan compared to the high-potential alloy.

Quality Substrate Material

Our magnesium anode is produced following the ASTM B843-M1C specification for high-potential anodes or ASTM B843-AZ63B specification for standard-potential anodes, based on the composition outlined below:

Element	High Potential (ASTM B843 – M1C)	Standard Potential (ASTM B843 – AZ63B)
Aluminum (Al)	0.01%	5.3 – 6.7%
Manganese (Mn)	0.5 – 1.3%	0.15 – 0.7%
Zinc (Zn)	—	2.5 – 3.5%
Silicon (Si)	0.05%	0.1%
Copper (Cu)	0.02%	0.02%
Nickel (Ni)	0.001%	0.002%
Iron (Fe)	0.03%	0.003%
Other Each	0.05%	—
Others Total	0.3%	0.3%
Magnesium (Mg)	Remainder	Remainder

 

Different Electro-potential Options

Two types of cast magnesium anodes are commonly available:

1. Conventional Magnesium Alloy Anode

A standard-potential anode exhibits a nominal corrosion potential of around -1.55 volts (compared to a Cu/CuSO4 reference electrode). It proves effective in soil environments where resistivity remains below 20 Ω·cm.

2. Enhanced Potential Magnesium Alloy Anode

High-potential magnesium anodes boast elevated open-circuit voltage and driving potential. They demonstrate an open-circuit potential ranging from negative 1.7 to 1.75 volts, representing a 20% to 30% increase over traditional magnesium anodes. This higher potential translates to increased current output and improved efficiency, offering ample cathodic protection while reducing anode consumption. These anodes are particularly suitable for structures situated in soils with resistivities surpassing 2,000 Ω·cm or for structures facing significant corrosion challenges.

Technical Measurement	High Potential	Standard Potential
Open Circuit Potential (-V)	1.7 ~ 1.75	1.5 ~ 1.55
Close Circuit Potential (-V)	1.58 ~ 1.62	1.45 ~ 1.50
Min. Current Capacity	500 A.h/lbs (1100 A.h/kg)	550 A.h/lbs (1230 A.h/kg)
Min. Current Efficiency	50%	55%

Remarks: Open/close circuit potential is with respect to a Saturated Calomel Reference Electrode.

Strict Quality Control

Adhering to ISO 9001:2015 guidelines, our anodes undergo manufacturing, inspection, and testing processes that adhere to rigorous quality control protocols, guaranteeing optimal performance levels.

Testing

We employ ISO 9001:2015 quality management system and rigorous internal testing standards to ensure the optimum lifespan and performance of our anodes. Each anode is labelled with a unique serial number for quality tracking.

Technical Measurement	Chemical Composition	Electrochemical Performance	Physical Properties
Testing Standard	ATSM A518 (Gr1)	ATSM A518 (Gr3)	Foundry ITP
Testing Content	Chemical Analysis	Circuit Potential / Anode Resistance / Current Efficiency	Surface Finish / Dimension & Weight / Steel Core / Cable Connection / Sealing / Backfill Packaging
Equipments	Optical Emission Spectrometer OBLF QSN 750	Electrochemical Analyzer EPI 200	Calibrated Digital Measuring Devices