A Comparison Between Corten Steel and its Alternatives

Corten steel is a popular type of steel, used specifically in extreme weather conditions due to its high level of weather and corrosion resistance. While Corten steel is extremely popular, it can be considerably harder to source than standard Euronorm designated materials. This blog post will outline the properties of Corten steel and its alternatives, to provide an insight into other grades of steel that may be suitable for your application.

What is Corten Steel?

As mentioned previously, Corten steel is a weather resistant steel that can also be called ‘Atmospheric Corrosion Resistant Steel’, and it is its alloying elements of copper and chromium that provide this level of atmospheric resistance.

Corten steel has a distinctive orange color, which is caused by the chemical composition forming a protective rust layer when exposed to extreme environments. There are two main grades of Corten steel; Corten A and Corten B.

Learn More: Corrosion-Resistant Steels: Corten A/B vs Stainless Steels

Corten A has added phosphorous, which makes it suitable for aesthetic facias and gas flue applications, while Corten B is better suited for heavy and load-bearing structures.

Grade	Thickness (mm) Strip Products	Plate Products	Yield Strength Rel N/mm² Minimum	Tensile Strength Rm N/mm² Minimum	Elongation A50 % Minimum
Corten A	2-12	6-12	345	485	20

Corten A Chemical Composition

C	0.15
Si	0.25/0.75
Mn	0.20/0.50
P	0.07/0.15
S	0.030
Al	0.015/0.06
Cu	0.25/0.55
Cr	0.50/1.25
Ni	0.65

Grade	Thickness (mm) Strip Products	Plate Products	Yield Strength Rel N/mm² Minimum	Tensile Strength Rm N/mm² Minimum	Elongation A50 % Minimum
Corten B	2-13	6-40	345	485	19

Corten B Chemical Composition

	%
C	0.19
Si	0.30/0.65
Mn	0.80/1.25
P	0.035
S	0.030
Al	0.020/0.06
V	0.02/0.10
Cu	0.25/0.40
Cr	0.40/0.65
Ni	0.40

S355JOW

S355JOW is an equivalent weathering steel to Corten B. Like Corten steel, S355JOW builds its own protective layer to prevent the steel from oxidation.

Grade	Min. Yield Strength ReH MPa						Tensile Strength Rm MPa
	Nominal Thickness (mm)						Nominal Thickness (mm)
	<16	>16 <40	>40 <63	>63 <80	>80 <100	>100 <150	>3	>3 <100	>100 <150
S355JOW	355	345	335	325	315	295	510/680	470/630	450/600

S355JOW Chemical Composition

	%
C	0.16
Si	0.50
Mn	0.50/1.50
P	0.035
S	0.035
N	0.009
Cr	0.40/0.80
Cu	0.25/0.55

S355JOWP

This grade of weathering steel has added phosphorus, and it is the equivalent grade to Corten A. This metal also has excellent self-protective properties, due to the layer of rust that forms after reaction with the atmosphere. This grade finds use in long-lasting and economical structural steel solutions, such as bridges.

Grade	Min. Yield Strength ReH MPa						Tensile Strength Rm MPa
	Nominal Thickness (mm)						Nominal Thickness (mm)
	<16	>16 <40	>40 <63	>63 <80	>80 <100	>100 <150	>3	>3 <100	>100 <150
S355JOWP	355	345					510/680	470/630

S355JOWP Chemical Composition

	%
C	0.12
Si	0.75
Mn	1.00
P	0.06/0.15
S	0.035
N	0.009
Cr	0.30/1.25
Cu	0.25/0.55

S355J2W

S355J2W is another grade that is equivalent to Corten B. It is an economical steel that is fully recyclable, and it can be used for either load-bearing applications or for cosmetic purposes in structures.

Grade	Min. Yield Strength ReH MPa						Tensile Strength Rm MPa
	Nominal Thickness (mm)						Nominal Thickness (mm)
	<16	>16 <40	>40 <63	>63 <80	>80 <100	>100 <150	>3	>3 <100	>100 <150
S355J2W	355	345	335	325	315	295	510/680	470/630	450/600

S355J2W Chemical Composition

	%
C	0.16
Si	0.50
Mn	0.50/1.50
P	0.030
S	0.030
N	0.009
Cr	0.40/0.80
Cu	0.25/0.55

Weathering Steel Products from Masteel

Masteel supply a range of weathering steel products to suit many applications, including Corten A, Corten B, S355JOW, S355JOWP, and S355J2W steels.

Our team can provide advice and support to anyone who needs a weathering steel and suggest the best solution for your application. If you would like any more information about our weathering steel solutions, including Corten steel, please contact us.