Comparison of Common Standards for Weathering Steel

International Tandard for Weathering Steel

Atmospheric corrosion resistant steel ( also known as weathering steel) is a type of low alloy structural steel with excellent strength, ductility, toughness，corrosion resistance, high temperature resistance, welding fabrication and other characteristics. Its corrosion resistance is significantly superior to that of carbon structural steel，while its production cost is significantly inferior to that of stainless steel. Weathering steels are widely used in railway vehicles, buildings, bridges, containers and other steel structures long-term exposed to the atmosphere. Several current international standards of weathering steels and their formulation were introduced, and the understanding of the current standards is of guiding significance for the alloying design, industrial production and practical use of weathering steels．

American ASTM A242 and ASTM A588 Weathering Steel Standard

In 1941, the United States issued the first standard ASTM A242 for weathering steel, and in 1968, issued the standard ASTM A588 for high strength low alloy structural steel and divided into two types of weathering steel. One is high phosphorus content (Mass fraction of P is 0.07%-0.15%), namely USS COR-ten A; The other is low in phosphorus content (Mass fraction of P is less than 0.04%), namely USS Cor-ten B. After the use of the standard, the alloy composition of USS COR-ten A still refers to ASTM A242 standard, while USS Cor-Ten B is classified into ASTM A588 standard due to its low phosphorus content and relatively weak corrosion resistance. The following table lists the chemical composition of common weathering steels according to ASTM A242 and ASTM A588. In 1975, ASTM issued ASTM A709 standard for carbon steel and High strength low alloy structural Steel used in Bridges.

Table1 Chemical compositions of commonly used weathering steels in ASTM A242 and ASTM A588 standards (mass fraction)

										%
Standard	C	Mn	P	S	Si	Cu	Ni	Cr	V	Al
ASTM A242/A242M	≤0.15	≤1.00	≤0.15	≤0.05	0.42	≤0.20	0.31	0.82	<0.01	0.08
ASTM A588/A588M	≤0.19	0.8~1.25	≤0.03	≤0.03	0.3~0.65	0.25~0.4	≤0.40	0.4~0.65	0.02~0.1	0.043

Steel enterprises in different countries use different names of weathering steel, but they refer to ASTM A242 and ASTM A588 two standards.

European BS EN 10155:1993 Weathering Steel Standard

At present, many European steel enterprises refer to the European standard BSEN 10155:1993 production of weathering steel. BS EN 10155:1993 specifies grades and toughness requirements for different weathering steels according to their welding properties. The following table lists the chemical composition of the weathering steels commonly used in BSEN 10155:1993.
Table2 Chemical compositions of commonly used weathering steels in BSEN 10155:1993 standards (mass fraction)

								%
Standard	C max	Si max	Mn	P	S max	N max	Cr	Cu
S235J0W	0.13	0.40	0.20~0.60	≤0.04	0.04	0.009	0.40~0.80	0.25~0.55
S355J0WP	0.12	0.75	≤1.00	0.06~0.15	0.04	0.009	0.30~1.25	0.25~0.55
S355J0W	0.16	0.50	0.50~1.50	≤0.04	0.04	0.009	0.40~0.80	0.25~0.55
S355J2G1W/S355J2G2W/S355K2G1W/S355K2G2W	0.16	0.50	0.50~1.50	≤0.035	0.035	-	0.40~0.80	0.25~0.55

Japanese JIS G 3125:2010 Weathering Steel Standard

Japanese weathering steel is manufactured to JIS G 3114:2008 and JIS G 3125:2010. JIS G 3125:2010 standard is suitable for rolling steel with excellent properties of weathering steel used in vehicles, buildings, towers and other structural parts. The following table lists the chemical composition of SPA-H/SPA-C weathering steels in JIS G 3125:2010 standard, where the upper limit of Mn mass fraction can be adjusted to more than 1.0% according to actual application.

Table3 Chemical compositions of SPA-H/SPA-C weathering steels in JIS G 3125:2010 standards (mass fraction)

								%
Standard	C	Si	Mn	P	S	Cu	Cr	Ni
SPA-H/SPA-C	≤0.12	0.20~0.75	≤0.60	0.07~0.15	≤0.035	0.25~0.55	0.30~1.25	≤0.65

Chinese GB/T 4171-2008 Weathering Steel Standard

The common weathering steel standard in China is GB/T 4171-2008. The designation of this standard refers to various domestic and foreign standards and classifies the weathering steel, including high weathering steel Q295GNH(hot rolled), Q355GNH (hot rolled), Q265GNH (cold rolled), Q310GNH weathering steel (cold rolled) and welding Q235NH, Q295NH, Q355NH, Q415NH, Q460NH, Q500NH, Q550NH, etc. The following table lists the chemical composition of weathering steel commonly used in GB/T 4171-2008.

Table4 Chemical compositions of commonly used weathering steels in GB/T 4171-2008 standards (mass fraction)

								%
Standard	C	Si	Mn	P	S	Cu	Ni	Cr
Q355GNH	≤0.12	0.2~0.75	≤1.00	0.07~0.15	≤0.020	0.25~0.55	≤0.65	0.30~1.25
Q235NH	≤0.13	0.1~0.75	0.20~0.60	≤0.03	≤0.030	0.25~0.55	≤0.65	0.40~0.80
Q355NH	≤0.16	≤0.5	0.50~1.50	≤0.03	≤0.030	0.25~0.55	≤0.65	0.40~0.80
Q500NH	≤0.12	≤0.65	≤2.0	≤0.025	≤0.030	0.20~0.55	0.12~0.65	0.30~1.25
Q550NH	≤0.16	≤0.65	≤2.0	≤0.025	≤0.030	0.20~0.55	0.12~0.65	0.30~1.25

Chinese TB/T 1979-2014 Weathering Steel Standard

TB/T 1979-2014 standard is mainly applicable to hot-rolled and cold-rolled steel plates, steel belts and sections of atmospheric corrosion resistant steel for railway vehicles. The following table lists the chemical composition of weathering steels commonly used in TB/T standard 1979-2014.

Table5 Chemical compositions of commonly used weathering steels in TB/T 1979-2014 standards (mass fraction)

										%
Standard	C	Si	Mn	P	S	Cu	Ti/V	Ni	Cr	RE
Q345NQR2	≤0.12	0.25~0.75	0.20~0.5	0.60~0.12	≤0.020	0.25~0.50	-	0.12~0.65	0.3~1.25	-
Q345NQR3	≤0.12	0.2~0.75	0.25~0.7	0.60~0.12	≤0.020	0.25~0.50	Ti≤0.03	-	-	0.01~0.04
Q345NQR4	≤0.12	0.2~0.75	0.20~0.5	0.60~0.12	≤0.020	0.25~0.50	V0.02~0.08	-	-	0.01~0.04
Q500NQR1	≤0.12	≤0.75	≤2.0	≤0.025	≤0.008	0.20~0.55	-	0.12~0.65	0.3~1.25	-
Q550NQR1	≤0.16	≤0.75	≤2.0	≤0.025	≤0.008	0.20~0.55	-	0.12~0.65	0.3~1.25	-

Chinese T/CSM 12-2020 Weathering Steel Standard

T/CSM 12-2020 standard was released in 2020. By adding a small amount of rare earth elements, adjusting the electrode potential of inclusion, reducing pitting tendency, and forming a dense and stable oxidation protective layer on the surface of metal materials, it can effectively improve the atmospheric corrosion resistance of materials.

Table5 Chemical compositions of commonly used weathering steels in T/CSM 12-2020 standards (mass fraction)

									%
Standard	C	Si	Mn	P	S	Cu	Ni	Cr	RE
Q235RE	≤0.22	≤0.35	≤1.4	≤0.045	≤0.050	-	-	-	0.01~0.045
Q355RE	≤0.24	≤0.55	≤1.6	≤0.035	≤0.035	≤0.040	≤0.03	≤0.03	0.01~0.045
Q355GNHRE	≤0.12	≤0.75	≤1.0	≤0.150	≤0.020	≤0.550	≤0.65	≤1.25	0.01~0.045
Q235NHRE	≤0.13	≤0.40	≤0.6	≤0.030	≤0.030	≤0.055	≤0.65	≤1.80	0.01~0.045
Q355NHRE	≤0.16	≤0.50	≤1.5	≤0.030	≤0.030	≤0.055	≤0.65	≤1.80	0.01~0.045
Q500NHRE	≤0.12	≤0.65	≤2.0	≤0.025	≤0.015	≤0.055	≤0.65	≤1.25	0.01~0.045
Q550NHRE	≤0.12	≤0.65	≤2.0	≤0.025	≤0.015	≤0.055	≤0.65	≤1.25	0.01~0.045

Corten Steel and Weathering Steel Supplier

As a professional supplier of corten steel, AHL STEEL has the following advantages:

Our professional packaging team ensures that your goods arrive in good condition.
A professional loading team avoids damage to the package.
A product label with a traceable batch number and shipping information.
Strict quality control systemHigh quality is guaranteed.
We have over 500 tons in stock in various sizes and materials.

For the latest price of weathering steel, please contact us or email us at info@offersteels.com