About Us
Our company produces high quality, standard sacrificial anodes used in ships, in its factory located in İzmir, Turkey. All Norm products are manufactured from zinc ingots certified to be %99.995 pure.
Frequently Asked Questions
- What is a sacrificial anode? Where is it used?
- What is corrosion?
- What is cathodic protection?
- What are the galvanic electropotential series of common metals in sea water?
A sacrificial anode is a metallic anode used in cathodic protection where it's intended to be dissolved to protect other metallic components. It's used primarily in ships below the waterline, in order to protect the hull and important components from corrosion.
Corrosion is the chemical or electrochemical reaction of metals with their environment, in which they gradually lose their metallic properties.
Cathodic protection is the stopping of anodic reactions on a metallic surface by making the metallic component that is to be protected the cathode of an electrochemical cell that is formed in the process. The goal in cathodic protection is to polarize the potential of the metallic component to be protected up to the open circuit potential of the anode. In order to accomplish this, a cathodic external current is applied to the metal.
Because of their different positions in the electrochemical series, when zinc and iron or steel are joined together and placed in an electrolyte, a cell is formed in which the zinc becomes the anode and the steel the cathode. The zinc then dissolves preferentially ("sacrificies") and the steel does not rust. This is the process that enables zinc coatings to protect steel at damaged areas.
Marine sacrificial zinc anodes, which are available in many shapes and sizes, are bolted onto ships' hulls and ballast tanks, rigs and other installations to protect the steel structure from corrosion. High purity zinc and a range of special alloys are used for cathodic protection to ensure that the surface remains active.
We design and manufacture our anodes to fit in order to insure the greatest protection. The contact between the anode and what it is protecting is vitally important.
The series are listed in the table below. If a pair of metals in this table is connected in sea water, the metal in the upper section of the table becomes the anode and is corroded.
| Activity | Metal | Voltage |
|---|---|---|
| More Active | Magnesium | -1.48 V |
| Zinc | -1.03 V | |
| Aluminum | -0.79 V | |
| Wrought Iron and Carbon Steel | -0.61 V | |
| Wrought Iron | -0.60 V | |
| Stainless Steel Type 430 AISI | -0.57 V | |
| Stainless Steel Type 304 AISI (18% Cr, 18% Ni) | -0.53 V | |
| Less Active | Yellow Brass | -0.40 V |
| Red Brass | -0.38 V | |
| Copper | -0.36 V | |
| Aluminum Bronze | -0.32 V | |
| Nickel | -0.20 V | |
| Titanium | -0.15 V | |
| Monel | -0.08 V |
- Are "sacrificial anode" and "zinc anode" the same thing?
- Do Norm anodes have warranty?
Yes, they're interchangeable terms. In the maritime sector, the term "sacrificial anode" is used more commonly than "zinc anode".
Norm manufactures its products according to international standards, and performs chemical and electrochemical analysis on each cast before sale. Customers are provided with chemical analysis reports of the anodes that they purchase, and are free to have the analysis done elsewhere to verify. Thus, Norm anodes are guaranteed to work.