COR-TEN Steel: what is it, characteristics, and benefits - Bertero

Material in use since the 1960s, easily confused with others (especially iron) at first glance. Discover what COR-TEN steel is, its main characteristics, and the benefits it offers.

Considering the widespread use of this material, it’s practically impossible not to have come across it: COR-TEN steel stands out, both for its intriguing rusty appearance and its versatility of use. Let’s find out what it is, its characteristics, and the advantages that make it the perfect choice.

A brief guide to COR-TEN steel

  1. What Is It?
  2. Characteristics
  3. Advantages

COR-TEN Steel: what is it?

COR-TEN steel falls into the category of low-alloy steels, known as weathering steels. Low-alloy steels are a specific type of steel that contains elements other than iron and carbon; what is added to the alloy is intended to improve the chemical and physical properties of the base steel.

In particular, COR-TEN (in its 1933 formulation, the year of the first patent by United States Steel Corporation) also contains copper, chromium, and phosphorus.

The name COR-TEN derives from the fusion of the two main characteristics of this metal:

  • High corrosion resistance (CORrosion resistance)
  • High tensile strength (TENsile strength)

There are primarily 3 types of COR-TEN available in the market.

  • COR-TEN A Steel
    Also known as COR-TEN with phosphorus. It offers eight times higher corrosion resistance than common carbon-based steels.
  • COR-TEN B Steel
    Also known as COR-TEN with vanadium. It is suitable for withstanding intense stress, making it particularly effective in construction projects such as pipelines, chimneys, silos, guardrails, bridges, and continuous facades.
  • COR-TEN C Steel
    This is a relatively recent variant, with superior performance. It has higher mechanical strength than types A and B, making it suitable for constructions subject to high mechanical stress.

Characteristics of COR-TEN steel

COR-TEN steel is primarily appreciated for one characteristic: its ability to self-protect against electrochemical corrosion. Thanks to the oxides of the alloying elements, COR-TEN generates a compact passive surface patina that virtually extends its usability indefinitely. A casual glance might make us think that the surface of this alloy is consumed by rust – nothing could be further from the truth! The patina that covers COR-TEN is what we could call its superpower, the feature that makes it durable and self-regenerating.

Over time, the coloration of COR-TEN may vary, but it always maintains a shade within the brown-bronze spectrum.

Due to the peculiarities of COR-TEN, it is highly valued in architecture, the world of outdoor art, and sculpture.

Advantages of COR-TEN steel

COR-TEN steel offers several advantages that make it perfect for various construction applications.

  • It is 100% recyclable: in addition to being extremely durable, it can be recycled virtually indefinitely without losing its unique properties.
  • It has a long lifespan.
  • It possesses high resistance to mechanical stress.
  • It has high resistance to atmospheric agents.
  • It requires minimal maintenance.
  • It is highly ductile and allows for a wide range of processing (bending, welding, forging).
  • It is cost-effective.

The characteristics of this alloy allow it to be used in many sectors:

  • Construction: for load-bearing structures, fixtures, and many other applications.
  • Furniture and Architecture: facades, outdoor and interior design, urban furniture.
  • Transportation and Large Structures: transportation infrastructure, bridges, wagons.
  • Storage Elements: pipelines, storage facilities, containers, or tanks.

Not to be overlooked is the aesthetic value of works made of COR-TEN, which maintain their texture and color characteristics for very long periods of time.