Selecting the right materials is one of the most important considerations when choosing an immersion heater. Without the right heater materials, equipment risks corrosion. This can result in product degradation, mechanical failure or damage, and can result in inefficiencies, leaks, or other hazards.
There is no one-size-fits-all solution for preventing this damage. Corrosion is affected by the processes, operating temperatures, environment, and product of a project. As such, each project needs special attention given to choosing the right materials to prevent corrosion.
In this article, we explore corrosion resistance of ferrous versus non-ferrous metals for process heater applications.
The corrosion resistance of the metals and alloys is always an important factor in choosing industrial heater materials. However, the selection does not hinge on this resistance alone. Other factors must be weighed against their importance, balancing corrosion risks with costs and durability.
This section explores the pros and cons of ferrous and non-ferrous metals, to help determine which may be the right fit for a given project.
Heavy-duty metals, like steel and iron, make up the ferrous metals category. The word ferrous, itself, means “containing or consisting of iron.” Common forms of this metal in construction and manufacturing include:
These materials are very strong and durable. As well, they are less expensive than non-ferrous metals. As such, they are reliable and budget-friendly metals where they are appropriate for a project and its operating conditions.
The drawback of ferrous metals, however, comes from the fact that they contain iron. Being composed partially or primarily of iron leaves them very prone to corrosion. So they are a poor choice where corrosion risks are significant.
Ferrous metals are also a heavier material. This can factor into the efficiency of transportation and require stronger support systems to install or use properly.
Non-ferrous metals are essentially any metal other than steel or iron. Common examples of non-ferrous include aluminum, tin, copper, nickel, titanium, and zinc. This category also includes alloys such as brass and bronze.
Because they are not iron, non-ferrous metals and alloys have greater corrosion resistance. This, along with their light weight, non-magnetic properties, and high conductivity make them a desirable option for many applications.
Not every project, however, benefits from these metals. The first limiting factor is cost. Non-ferrous metals are significantly more expensive than steel or iron. They are also not as strong or durable as their ferrous counterparts.
Where corrosion resistance and weight are the main concern, non-ferrous metals are ideal heater materials. If budget and durability are more important, ferrous metals are often the best choice. But what if you need to split the difference?
Ferrous metals can be given added protections to improve their performance. For instance, wrought iron is a corrosion-resistant metal, despite being primarily iron. This is achieved through a protective coating. If the coating is damaged, the protection is lost.
Another approach is to include other protective materials in the metal itself. Stainless steel, for example, contains chromium. The chromium increases corrosion resistance.
Treated and specially formulated ferrous metals help to better balance corrosion resistance without sacrificing durability. While they have a higher cost than standard ferrous materials, they are more budget friendly than many non-ferrous metals. For many heater applications, they offer an ideal alternative.
Wattco custom-manufactures electric process heaters. Our team of engineers examines the specific temperatures, wattages, target mediums, budget, and environmental considerations of your product to select the ideal heater materials.
Contact Wattco today for electric heater quotes and information.