Difference Between Cast Iron vs Cast Steel Bollard
Mooring bollard is a vital component of any mooring system. It is usually the short post and is used as the anchor point for mooring lines to be fixed to secure the vessel alongside jetties/quay, berths, wharves and dolphins in ports and harbors.
Since the beginning of maritime history, people have been using wooden posts or iron structures for this purpose. With the advancement of manufacturing technology, engineers and manufacturers of today have considered the strength and durability of materials while also providing a safety factor as a safety cushion.
Mooring bollard is a simple and essential mooring device. However, not all bollards are created equal. Different design profiles, sizes and mooring line capacities are considered to adjust in each port. The suited mooring system applications considers the physical conditions, and the type of ships it will serve.
Designing and choosing the right components are a big part in marine construction. It is crucial to know what type of material to be utilized. Ductile cast iron, cast steel and stainless steel are some of the main materials used to make marine mooring bollards. They each have advantages in their applications.
In this article, we will focus mainly on the difference of cast iron vs cast steel.
Carbon content is the main difference
Iron and steel are both ferrous metals composed primarily of iron atoms. Pure elemental iron is too soft to be useful but when mixed with carbon, it gets harder, and therefore more useful. In fact, the carbon composition is the main distinction between cast iron and steel. Cast iron typically contains more than 2 percent carbon, while cast steel often contains between 0.1–0.5 percent carbon.
Steel is excellent at withstanding sudden impacts without bending, deforming, or breaking due to its ability to withstand high stress and strain forces.
Strength without ductility results in a brittle material that is highly susceptible to fracture—and cast iron is one good example of strength without ductility. Because of its brittleness, cast iron has a limited range of application.
While iron may be easier to work with in most casting applications, steel has an optimal mix of both strength and ductility for many applications, and it is extremely tough. Steel is the most widely used metal in the world due to its impact-resistant qualities and all-around load-bearing nature making it desirable for many mechanical and structural applications.