Corten Steel
Suppliers and exporters of Corton Steel Plate Products.
Weather resistant steel
Physical Properties
| Weather resistant steel |
Standard |
Tensile Strength MPa |
Yield Strength MPa |
Elongation in 2 inches (min.) % |
| Corten-A |
US steel |
470-630 |
355 |
20 |
| IRSM 41-97 |
Indian Railways |
480 min |
340 min |
21 |
Chemical Properties
| Weather resistant steel |
C |
Mn |
P |
S |
Si |
Cr |
Ni |
Mo |
Cu |
Fe |
| Corten-A |
0.12 |
0.20-0.50 |
0.070-0.150 |
0.030 |
0.25-0.75 |
0.50-1.25 |
0.65 |
- |
0.25-0.55 |
- |
| IRS M-41 |
0.10 |
0.25-0.45 |
0.075-0.112 |
0.030 |
0.28-0.72 |
0.35-0.49 |
0.20-0.49 |
- |
0.30-0.39 |
- |
Scope
COR-TEN A applies to plates up to 12.5mm in thickness, COR-TEN B applies to plates up to 50mm in thickness.
Definition
Weathering means that due to their chemical compositions COR-TEN A and COR-TEN B steels, when utilised unprotected, exhibits increased resistance to atmospheric corrosion compared to unalloyed steels. This is because it forms a protective layer on its surface under the influence of the weather.
The corrosion retarding effect of the protective layer is produced by the nature of its structure components and the particular distribution and concentration of alloying elements in it. The layer protecting the surface develops and regenerates continuously when subjected to the influence of the weather.
Formation, duration of development and protective effect of the covering layer on weathering steels depend largely upon the corrosive character of the atmosphere. Its influence varies and depends mainly upon general weather condition (e.g. continental) macroclimate (e.g. industrial, urban, maritime or countryside climate) and the orientation of the structure components (e.g. exposed to or shaded from the weather, vertical or horizontal position). The amount of aggressive agents in the air has to be taken into account . In general the covering layer offers protection against atmospheric corrosion in industrial, urban and countryside climate.
When utilising this steel in unprotected condition it is up to the designer to take into account the expected loss of thickness due to corrosion and as far as necessary, compensate for it by increasing the thickness of the material.
In cases of particular air pollution by aggressive agents conventional surface protection is recommended. Coating is absolutely necessary in cases of contact with water for long periods, when permanently exposed to moisture, or if it is to be used in the vicinity of the sea. The susceptibility of paint coats to undercreepage by rust is less in the case of weathering steel than in the case of comparable non-weathering steel.
Chemical Composition (heat analysis, %)
| Grade |
C |
Si |
Mn |
P |
S |
Cr |
Cu |
V |
Ni |
| COR-TEN A |
0.12 |
0.25-0.75 |
0.20-0.50 |
0.07-0.15 |
0.030 |
0.50-1.25 |
0.25-0.55 |
|
0.65 |
| COR-TEN B |
0.16 |
0.30-0.50 |
0.80-1.25 |
0.030 |
0.030 |
0.40-0.65 |
0.25-0.40 |
0.02-0.10 |
0.40 |
In order to obtain fine grain structure a sufficient amount of nitrogen absorbing elements is added (e.g. ≥0.02% Al).
Mechanical Properties, in the state of delivery condition.
At room temperature for plates ≥3mm in thickness (transverse test specimans, according to EN 10002). Requirements to hot rolled plates ≤3mm in thickness according to EN 10025-5.
| Grade |
Minimum
yield point
(ReH Mpa *) |
Tensile
strength
Rm MPa |
Minimum
elongation
A (Lo=5.65
√So) % |
COR-TEN
A |
355 |
470-630 |
20 |
*) 1 Mpa = 1N/mm2
The notched-bar impact energy is determined on ISO-V longitudinal test specimans at a temperature of - 20°C as an average of three tests. For product thicknesses ≥10mm the average value is at least 27 J. For thicknesses between 10mm and 6mm, the minimum impact value is reduced proportionally to the speciman width (product thickness).
No impact test is performed on products below 6mm in thickness.
Number of Tests
| 1 tensile test |
1 test specimen per 40 t from each heat*) |
| 1 notched bar impact test |
1 set specimens per 40 t from each heat *) |
| (3 specimens) |
(at test temperature -20°C) |
Applications
Corrosion resistant steel - Weathering Steel grade The steel is used for various types of welded, bolted and riveted constructions e.g. steel frame structures, bridges, tanks and containers, exhaust systems, vehicles and equipment constructions.
Basic guidles for the use of this steel in the unprotected condition are described in EN 10025-5 and DASt rule 007.
The entire application technology is of fundamental importance for the performance of the products made from this steel. It must be taken into account that not only general climate conditions but also specific unfavourable local climate conditions in the broadcast sense as well as details of a construction may affect the corrosion behaviour of unprotected weathering steel. The dependency on these facts makes it understandable that no warranty can be given. It is recommended to control the corrosion progress of protected parts out of weathering steel exposed to the influence of weather in reasonable time intervals. A minimum thickness of 5mm is recommended when exposed to the weather in the unprotected condition.
To use the benefits of the higher atmospheric corrosion resistance of COR-TEN in comparison to unalloyed steel it is necessary that design and execution of structures as well as the performance of maintenance works allow an impeded formation and regeneration of the protective rust layer. The methods must meet the latest requirements of technical progress and must be suited for the proposed application. Due consideration must be given to relevant construction specifications.
The selection of the material is up to the purchaser.
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