Weathering Steel Plate

Weathering Steel Plate

Weathering steel is a group of steel alloys which form a stable rust-like appearance after several year's exposure to weather. It is also well known by the genericized trademark COR-TEN steel or corten steel, which refers to the two distinguishing properties of this type of steel: corrosion resistance and tensile strength.
It is featured with atmospheric corrosion resistance. This is because the steel forms a protective layer on its surface under the influence of the weather. In other words, the steel is allowed to rust in order to form the protective coating.
The use of weathering steel reduces maintenance cost for steel structures and provides solution for outdoor unprotected steel structure of fire-proof and corrosion-proof, such as high voltage towers. Compared with ordinary carbon steel, weathering steel has better corrosion resistance in the atmosphere and is greener without painting or coating, which is normal for carbon steel . Compared with stainless steel, there is only trace alloy elements accounting for a few percent, not like that of stainless steel accounting for more than ten percent. So the cost of weathering steel is lower.
It is popularly used in bridges,architectures, outdoor sculptures, towers, oil derrick, vehicles, containers, etc due to its properties and natural appearance.

Weathering steel is made of common carbon steel by adding a small amount of copper, nickel and other corrosion resistant elements. It has the characteristics of high quality steel, such as strength, plastic casting, forming, welding and cutting, abrasion, high temperature and fatigue.The weatherability is 2~8 times of common carbon steel, the coating ability is 1.5~10 times of common carbon steel, can reduce the use of thin, exposed use or simplify the use of coating.The steel has the characteristics of rust resistance, corrosion resistance, life extension, thinning and energy saving, benefiting component manufacturers and users.Weathering steel products for the manufacture of containers, railway vehicles, oil derricks, harbour buildings, oil platforms and chemical and petroleum equipment containing hydrogen sulphide corrosive medium containers and other structural parts.

Principles of Weathering Steel

After the addition of trace elements such as phosphorus, copper, chromium and nickel into the steel, a dense and highly adherent protective film is formed on the surface of the steel, which hinders the diffusion and development of rust and protects the substrate below the rust layer to slow down its corrosion rate.In rust is formed between the layer and the substrate of about 50 microns to 100 microns thick amorphous spinel and dense oxide layer and substrate metal stick fine, because of the existence of the oxide film layer prevents the oxygen in the atmosphere and water infiltration to the steel matrix, and slow down the corrosion to steel material depth development, greatly improve the atmospheric corrosion resisting capacity of steel materials.Weathering steel is a kind of steel that can be used thiningly, exposed or simply painted to resist corrosion, prolong life, save labor and reduce consumption, and upgrade. It is also a kind of steel that can be integrated into new mechanism, new technology and new process of modern metallurgy to make its sustainable development and innovation.

Weathering Steel Manufacturing Process

Weathering steel generally adopts such process routes as concentrate in furnace - smelting (converter, electric furnace - microalloying treatment - blowing argon -LF refining - low superheat continuous casting (feeding rare earth wire)- controlled rolling and cooling.During smelting, the waste steel is added into the furnace together with the charge, and the steel is smelted according to the conventional process. Deoxidizer and alloy are added after the steel is produced. After argon blowing, the molten steel is then cast, and the molten steel after argon blowing and temperature adjustment is cast into slab by continuous casting machine. Due to the addition of rare earth elements in steel, weathering steel is purified and the inclusion content is greatly reduced.

Dimension Table

Product name Weathering Resistant Steel Plate
Standard ASTM A242/A242M-13, ASTM A588/A588M-2015, ASTM A606/A606M-18, ASTM A871/A871M-2014, GB/T4171-2008, JISG3125-2004, EN 10025-5
Grade Corten A, Corten B, ASTM A588 GrA/B/K, ASTM A871 Gr60/65, SPA-H,S235J0W,S235J2W,S355J0W,S355J2W,Q235NH,Q355NH
Thickness from 2 mm to 200mm
Width from 750mm to 3200mm
Length Up to 12,000mm
type Weathering steel / corten steel
Hot Rolled Corten steel Plate size 3-150mm * 750-3200mm * 3000-12000mm

Evolution of Weathering Steel

Chemical Composition for Corten Weathering Steel Plate

Grade C Mn P S Si Ni Cr Mo Cu V Nb
A588 Gr.A ≤0.19 0.80–1.25 ≤0.04 ≤0.05 0.30–0.65 ≤0.40 0.40-0.65  - 0.25–0.40 0.02–0.10  -
A588 Gr.B ≤0.20 0.75–1.35 ≤0.04 ≤0.05 0.15–0.50 ≤0.50 0.40-0.65   0.25–0.40 0.01–0.10  -
A588 Gr.C ≤0.15 0.75–1.35 ≤0.04 ≤0.05 0.15–0.40 ≤0.50 0.30-0.50  - 0.20–0.50 0.01–0.10  -
A588 Gr.K ≤0.17 0.50–1.20 ≤0.04 ≤0.05 0.25–0.50 ≤0.50 0.40-0.70 ≤0.10 0.30–0.50 0.01–0.10 0.005-0.05

Mechanical Property
Grade Thickness of Steel (mm) T.S. (Mpa) Rm Elogation (A%)
≤16 >16-40 >40-80
Min Y.S. (Mpa)
A588 Gr.A ≥345 ≥485 ≥21
A588 Gr.B
A588 Gr.C
A588 Gr.K

Atmospheric Corrosion Resistant Steel Correspondence Table

TKS Standard EN Standard EN 10025-5 ASTM Standard Material No.
Weathering Steel B* S355JOW S355J2W+N ASTM 588 GRADE A 1.8965