What Is Corten Steel Welding?

Weathering steel is Corten Steel. Rusty surfaces protect them from adverse weather conditions and corrosion when exposed to the weather. The properties of corten steel include high strength, toughness, and ductility. In addition, the alloy is resistant to atmospheric corrosion, making it a popular choice for outdoor architectural features and sculptures.

Copper, manganese, and nickel make up the alloy. Steel is manufactured by adding a layer of corrosion-resistant material to its surface. Steel is protected from rust and weathering by this layer.

Corten Steel is ideal for outdoor applications because of its properties. Even in harsh environments, the steel does not corrode or rust. Abrasion and fatigue resistance is also high.

Architecture and landscape design often use Corten Steel. Fences, gates, bridges, and other structures can be made of steel. Additionally, it can be used to create sculptures and other decorative items.

Corten Steel vs Stainless Steel

There are a few key factors to consider when choosing between Corten steel and stainless steel. The rust-like appearance of Corten steel can add visual interest to your project.

Corten steel, however, may not be the best choice for applications that require a lot of wear and tear since it is not as durable as stainless steel.

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Since stainless steel does not corrode or rust in most environments, it is a more versatile material. In addition, it is easier to maintain than Corten steel. Corten steel and stainless steel are ultimately a matter of personal preference and needs.

Corten Steel vs Mild Steel

There are two types of steel commonly used in construction: Corten Steel and Mild Steel. Corten steel is a type of weathering steel that resists rust. Corten steel is more resistant to rusting than mild steel, which is non-weathering steel.

The main difference between Corten steel and mild steel is its corrosion resistance. Corten steel has a higher level of corrosion resistance than mild steel due to the way it is manufactured. In applications where exposure to the elements is likely, such as outdoor sculptures and building facades, Corten steel is a better choice.


Since mild steel is less expensive than Corten steel, it is often used for structural applications. There are also structural uses for corten steel, but it is more expensive than mild steel.

Corten Steel Grades

  • CORTEN is a Trademark of US Steel. CORTEN Means:

    • CO: Corrosion

    • R: Resistance

    • TEN: Tensile Strength

    The common Corten Steel Grades are: ASTM A242, ASTM A606, ASTM A588 & ASTM A847

Corten Steel Chemical Composition & Mechanical Properties

As listed in the table for ASTM A606 type Corten Grades, Corten steel is a type of weathering steel made of copper, chromium, and nickel. ASTM A242, ASTM A606, ASTM A588 & ASTM A847 are also notable grades for this type of steel.

As a result of its chemical composition, it is able to create a protective layer on its surface that prevents corrosion. The layer also changes the color of the metal over time, giving Corten steel its distinctive appearance.

You can refer to the chemical & mechanical properties of ASTM A606, and ASTM A588 in the below table:


astm image


As well as its aesthetic appeal, corten steel has excellent mechanical properties, making it a popular choice for outdoor structures. ASTM A Type 4 Grade requires a minimum tensile strength of 70 Ksi and minimum yield strength of 50 Ksi.

Corten Steel Welding

While welding Corten steel can be tricky, with the right preparation, it can be done successfully.

With thick plates, the first step is to preheat the metal. This will prevent any warping or cracking during welding. Welding can begin once the metal is hot. When TIG welding, use a gas lens cup to protect the weld from the wind.

corten steel welding

Welding Preheat & Interpass Temperature for Corten Weathering Steel

When welding Corten steel, preheat and interpass temperatures are important considerations. A preheat temperature of 150-225 degrees Fahrenheit should be used, and an interpass temperature of 400 degrees Fahrenheit should be used. The following are the preheat requirements based on AWS D1.1:

  • For plate thickness up to 3/4 inches, no preheat is required.

  • For thickness above 3/4 inches, preheat to 100-150 degrees Fahrenheit minimum.

  • For thickness above 2.5 inches, preheat to 2

Corten Weathering Steel Welding Electrode/Rods & Welding Wires

Stick (SMAW) Welding Electrodes/Rods and TIG-MIG Filler Wires can be used to weld Corten Steel. These consumables are recommended for welding Corten Steel using Stick Welding, TIG Welding, MIG Welding & FCAW Welding.


Materials such as ASTM A242, ASTM A606, ASTM A588 & ASTM A847 can be welded with welding rods and welding filler wire.


Stick Welding (SMAW) of Corten Steel: E7018, E7018-W1, E8018-W2.

Welding of Corten Steel using TIG-MIG welding filler wire: ER70S-2, ER70S-6, ER80S-Ni1.

Corten Steel Welding using FCAW: E71-T1C, E81T1-Ni1C, E 80T-W.

Corten Weathering Steel Stick Welding (SMAW)

When exposed to the elements, corten steel forms a rust-like patina. Outdoor sculptures and architecture often use it. The SMAW (stick) welding process can be used to weld corten steel.


E7018 is the most common electrode for welding Corten steel. Welds produced by this electrode are medium- to deep-penetrating with good mechanical properties. Despite its versatility, it is most commonly used in flat and horizontal positions.


The E7018-W1 and E7018-W2 welding electrodes are specifically designed for welding Corten steel. As a result of its higher weld deposit, it is more corrosion-resistant than E7018. Besides being able to be used in all positions, it is most commonly used in the flat and horizontal positions.


Welding Corten Steel To Mild Steel

Corten steel can be welded to mild steel without any problems. For welding Corten Steel to Mild Steel, use E7018 or E7018-W1, or E8018-W2. ER70S-2, ER70S-6, and ER80S-Ni1 can be used for TIG and MIG welding.

Welding Corten Steel To Stainless Steel

Welding Corten Steel to Stainless Steel is a process of joining two different types of steel together. When exposed to the elements, corten steel will form a rust-like appearance on its surface. Food and medical applications use stainless steel, which does not corrode.


Stainless steel and carbon steel should be welded together with a filler metal that has the same corrosion resistance as stainless steel. Corten steel could corrode and fail prematurely if the filler metal has lower corrosion resistance.


To weld Corten steel to mild steel properly, use E309L Stick Welding Rod or ER309L TIG-MIG Filler Wire. Welding Corten steel to mild steel properly requires E309L Stick Welding Rod or ER309L TIG-MIG Filler Wire. Stainless steel material is diluted less when welded with low heat input.


Before welding, the weld should be cleaned of all contaminants. Remove any paint, grease, or dirt from the surfaces that will be welded using a wire brush or grinder.

Tig-Mig Welding Corten Steel

Corten steel can be tricky to weld, but with the right techniques, it can be a great way to add strength and weather resistance to your project. Corten is a great material for tig welding, as it produces clean, strong welds. Tig welding Corten steel: Here are a few tips:


You should make sure your base material is clean and free of rust and scale.

Preheat the material if possible, to help avoid cracking during welding.

Use a filler metal that has a similar composition to the base metal.

Avoid overheating the steel by welding slowly and cooling it.


What Do You Weld A588 Steel With?

In order to weld A588 steel, a welder must use the correct welding rods and electrodes. The alloy steel A588 is composed of carbon, manganese, silicon, phosphorous, and sulfur.


It is recommended that welding rods and electrodes used to weld this type of steel have a high manganese content.

Can You Weld Corten Steel With 7018?

Corten steel is a little different from other types of steel when it comes to welding. In order to get the best results, it’s important to use the right type of welding wire and set up the machine correctly. For welding Corten steel, some welders use 7018 welding wire.


It’s a good choice for most applications, but do some testing before you start welding on a critical project.


Is Corten Steel Mild Steel?

Weathering steel is corten steel. Weathering steel is not mild steel. The corrosion resistance of corten steel is higher than that of mild steel.

Corten Steel Strength And Weakness

The weathering steel Corten is well-known for its durability and strength. In outdoor applications, it is often exposed to the elements. Corten steel is strong and durable, but it does have some weaknesses. Rust is one of its weaknesses. It is quite easy for corten steel to rust if it is not properly maintained, which can cause corrosion and damage. Corten steel also tends to deform over time.


Insufficient support can cause the metal to stretch and sag. Even though these weaknesses should be considered when choosing corten steel for a project, you shouldn’t let them discourage you from using it. The beauty and functionality of corten steel can last for many years with proper maintenance and installation.


By alloying copper, chromium, and nickel, corten steel is weather-resistant steel. Weathering steel is primarily composed of this material. Unlike painted steels, weathering steels, such as COR-TEN, form a stable rust-like appearance if exposed to the weather for an extended period of time.


Rain, snow, ice, fog, and other meteorological conditions are not corrosive to COR-TEN because it forms a rust-like surface on its surface. This red oxide film self-repairs and prevents further corrosion. Because of its unique appearance, this type of steel is commonly used in outdoor sculptures and architectural features.