A34    
  Indaten® atmospheric corrosion resistant steels   Last update: 2010-8-10

When used uncoated and exposed to bad weather, a protective oxide layer develops on the steel surface. That is why this steel is often called “the weathering steel”.
 

Properties
   

Indaten® 355 is a range of steels with improved resistance to atmospheric corrosion that meet the requirements of the EN 10025-5:2005 standard. These grades are fine-grain, high-strength structural steels that have been optimised to give improved processing and in-service performance.
 

Advantages
   

With their characteristic colour, Indaten® 355 steels are used in architectural projects either to harmonise with the environment or to create a pleasing contrast with other materials, such as stainless steel. When used uncoated and exposed to bad weather, an oxide layer develops on the steel surface, forming a purplish-brown, finely grained patina that bonds very strongly to the steel and protects it. If the patina is damaged, the steel re-oxidises, thus repairing the patina and maintaining the protective barrier. Indaten® 355 can also be coated (paint, metallic coatings etc). In the case of coated parts, the protective layer prevents rust propagation under the paint layer.

Experience has shown that the adhesion of organic coatings on Indaten® 355 is superior to bonding on other carbon steel grades.
 

Applications
   

Indaten® 355 has a wide range of applications: architecture, sculpture, engineering structures, smokestacks, freight wagons, silos, containers and pylons. When used uncoated, no maintenance is required and the material will not deteriorate through corrosion.

 

The efficiency of the corrosion protection largely depends on the speed of patina formation. For optimum patina formation, Indaten® 355 can be used in a non-confined environment, even in the presence of sulphuric fumes. However, it is strongly recommended not to expose Indaten® 355 to condensation or repeated soiling, particularly in environments containing free chlorine.
 

Weldability
   

Indaten® 355 has excellent weldability with all the usual welding processes thanks to its low carbon content and fine-grained structure.

 

Shielded metal arc welding (process no. 111, SMAW)
SupplierReferenceEN ISOAWS
EsabOK 73.08*2560-A / E 46 5 Z B 32A5.5 / E8018-G
OK 48.08*2560-A / E 42 4 B 32 H5A5.1 / E7018
Lincoln ElectricConarc 55CT SRP*499 / E 46 5 Mn1Ni B 32 H5A5.5 / E8018-W2-H4R
Conarc 60G**757 / E 55 4 Z B 32 H5A5.5 / E9018M-H4
Conarc 70G**757 / E 55 4 1NiMo B 32 H5A5.5 / E9018-G-H4
S.A.F. Air LiquideSafer CU 56**499 / E 464 Z B 32 H5A5.5 / E8018-G
Safer NF 52**499 / E 424 B 54 H5A5.5 / E7028
499 / E 423 B 74 H5
Safer NF 510**499 / E 423 B 32 H5A5.5 / E7018
ThyssenSH Patinax KB**499 / E 38 3 Z 1 NiCu B 42A5.5 / E7015-G

* Specific electrode

** Specially adapted electrode

 

Submerged arc welding (process no. 21, SAW)

The filler materials to be used are the same as those recommended for welding steels with the same mechanical properties. As SAW involves strong inherent dilution, the welds will develop a patina.
The mechanical properties obtained in fusion zones meet the normal mechanical property requirements for the base metal.
SupplierReferenceEN ISOAWS
EsabFil Autrod 13.36*756 / S2Ni1CuA5.23 / EG
OK Flux 10.71 and 10.81 to 10.83*  
Lincoln ElectricFil LNS 163*  
Flux P230*760 / S A AB 1 67 AC H5 
Fil L60**756 / S1A5.17 / EL12
Flux 780**760 / S A AR/AB 1 78 AC H5 
Fil L61**S2SiA5.17 / EM12K
Flux 860**760 / S A AB 1 56 AC H5 
S.A.F. Air LiquideFil AS 26**756 / S1A5.17 / EL12
Flux AS 50**756 / SF 35 0 MS 1 S 1A5.17 / F6-A0-EL12
Fil AS 35**756 / S2A5.17 / EM12K
Flux AS 50**756 / SF 38 0 MS 1 S 2A5.17 / F7-A0-EM12K
ThyssenUnion Patinax U*756 / S 42 2 FB S0A5.23 / F7A2-EG-G
Flux UV 420 TT / UV 420 TT-LH*760 / SA FB 1 65 DC / SA FB 1 65 DC H5 

* Specific welding wire/flux couple

** Specially adapted welding wire/flux couple

 

Gas metal-arc welding (process no. 135, GMAW)

The thin wires used for equivalent carbon steel grades can also be used for Indaten® 355 steels; copper-plated wires deposit more copper on the surface of the welded zone, which contributes to the development of a patina on the welds. The cored wires to be used are also the same as those used for the equivalent carbon-manganese steel grades.
SupplierReferenceEN ISOAWS
EsabOK Autrod 12.51**440 / G3Si1A5.18 / ER70S-6
OK AristoRod 13.29**12534 / GMn3Ni1CrMoA5.28 / ER110S-G
Lincoln ElectricLNM 28*12070 / G465MG3Ni1A5.28 / ER80S-G
LNM Ni1** A5.28 / ER80S-Ni1
S.A.F. Air LiquideNertalic 70 A**440 / G3Si1A5.18 / ER70S-6
ThyssenUnion Patinax*440 / G423CGOA5.18 / ER70S-G

* Specific welding wire

** Specially adapted welding wire

 

Flux-cored arc welding (process no. 136, FCAW)

The process is suitable for the assembly of thin products with the same welding parameters recommended for equivalent carbon-manganese steel grades. If a filler wire is used, it must be of the same type as the base metal.
SupplierReferenceEN ISOAWS
EsabOK Tubrod 14.01*17632-A / T 42 2 Z M M 2 H10A5.18 / E70C-GM
OK Tubrod 15.00**758 / T 42 3 B M 2 H5A5.20 / E71T-5H4
758 / T 42 3 B C 2 H5A5.20 / E71T-5MH4
OK Tubrod 15.17**758 / T 46 4 1Ni P M 2 H5A5.29 / E81T1-Ni1M
758 / T 46 3 1Ni P C 2 H5 
Lincoln ElectricOutershield 500CT-H*758 / T 50 5 Z P M 2 H5A5.29 / E81T1-G-H4
S.A.F. Air LiquideSafdual 31*758 / T 42 4 B M 2 H5A5.20 / E71T5
Safdual 248*758 / T 46 A Z MM 1 H5A5.29 / E81T1G-W2M

* Specific welding wire

** Specially adapted welding wire
 

Recommendations for use
   

Appearance of the patina

 

Outdoor use: the patina forms naturally in the open air (over a period of three to four years). Variations in appearance will be observed, depending on the water condensation, evacuation and evaporation conditions. After a few years, the patina will stabilise, even in an industrial, sulphur-containing or rural environment. To ensure optimum patina formation and limit the formation of rust streaks, the oxidation process can be accelerated artificially by first descaling the surface (by sandblasting or shotblasting) and then subjecting it to alternate periods of dry and humid conditions.

 

Indoor use: to preserve the natural appearance of the material and at the same time avoid powdery oxide deposits that may cause staining, the following three steps are recommended:

  • First remove all dusty deposits, stains or surface defects, then apply a chemical treatment to those areas where corrosion has not yet developed
  • Clean the surface with water, brush and dry
  • Finally, apply a colourless, matt, UV-resistant varnish

 

Use painted: as the surface has a high reactivity, it is recommended that the first coat of paint be applied on a clean surface immediately after pickling or sandblasting.

The presence of copper in the oxide layer contributes to the formation of a strongly bonded, elastic and compact patina on the surface of Indaten® 355 in the course of the corrosion process. The chromium and nickel contribute to the formation of insoluble alkaline sulphates, which will seal the pores of the oxide layer, thereby protecting the metal from water and oxygen. Silicon, and to a lesser extent phosphorus, also has a favourable effect on corrosion resistance.

 

Corrosion in a salt spray atmosphere (according to ASTM B117)

 

Tests were conducted in a chamber at a temperature of 35°C, in a humid atmosphere with a 5% concentration of NaCl. Weight loss was measured after 1000 hours. The sample was weighed before and after the test, and the rust was removed with an acid solution.

 

Atmospheric corrosion

 

The samples were exposed to an industrial, marine atmosphere for 12 months.
 

Brand correspondence
   
 EN 10155:1993JIS G3114ASTMEN 10025-5:2005Old brand names
Indaten® 355AS355J0WPSMA 50AWA242 Grade A/A606 T2/A606 T4S355J0WPEnsacor® A
Indaten® 355DS355J2W  S355J2WEnsacor® D
 

Dimensions
   

Mill finish
Thickness (mm)Indaten® 355AIndaten® 355D
Min widthMax widthMin widthMax width
1.70 ≤ th < 2.0063012509001050
2.00 ≤ th < 2.4014401260
2.40 ≤ th < 2.501450
2.50 ≤ th < 3.001540
3.00 ≤ th < 3.5016801630
3.50 ≤ th < 4.001800
4.00 ≤ th < 4.501830
4.50 ≤ th < 5.0019001930
5.00 ≤ th < 9.5021302130
9.50 ≤ th < 10.301930
10.30 ≤ th < 13.001980
13.00 ≤ th < 16.0019301930


Pickled
Thickness (mm)Indaten® 355AIndaten® 355D
Min widthMax widthMin widthMax width
1.70 ≤ th < 2.0063012509001050
2.00 ≤ th < 2.4014401260
2.40 ≤ th < 2.501450
2.50 ≤ th < 3.001540
3.00 ≤ th < 3.5016801630
3.50 ≤ th < 4.001800
4.00 ≤ th < 4.501830
4.50 ≤ th < 5.0019001930
5.00 ≤ th < 6.1021302130
6.10 ≤ th < 7.1015501550




 

Mechanical properties
   
 
Notes
Direction
Thickness (mm)
Re (MPa)
Rm (MPa)
A80 (%)
A 5.65√So (%)
Bending ratio (th)
KV 0°C (J)
KV -20°C (J)
Indaten® 355A1L6 - 16-----≥ 27-
T1.7 - 3≥ 355510 - 680≥ 18-≥ 1.5--
3 - 10490 - 630-≥ 22≥ 2
10 - 16≥ 3
Indaten® 355D L5 - 12.7------≥ 27
T1.8 - 2≥ 355510 - 680≥ 14----
2 - 2.5≥ 15
2.5 - 3≥ 16
3 - 12.7470 - 630-≥ 20
Values in bold: tighter than the standard
1. For impact resistance at lower temperatures, please check with ArcelorMittal technical representative.
 

Chemical composition
   
 
C (%)
Mn (%)
P (%)
S (%)
Si (%)
Al (%)
Cu (%)
Cr (%)
Ni (%)
Mo (%)
Ceq (%)
Galvanisation
Indaten® 355A ≤ 0.120 ≤ 1.00 0.060 - 0.150 ≤ 0.015 0.20 - 0.50 ≥ 0.020 0.25 - 0.55 0.40 - 0.80 ≤ 0.30 - ≤ 0.45 No
Indaten® 355D ≤ 0.160 0.50 - 1.50 ≤ 0.030 ≤ 0.030 ≤ 0.50 ≥ 0.020 0.25 - 0.55 0.40 - 0.80 ≤ 0.65 ≤ 0.30 - No
Values in bold: tighter than the standard

The chemical properties given are based on cast analysis data.

For Indaten® 355D, Zr ≤ 0.15%


   
For commercial information (quotations, deliveries, product availability):

For technical questions about these products: fce.technical.assistance@arcelormittal.com
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All details provided in the ArcelorMittal Flat Carbon Europe S.A. catalogue are for information purposes only. ArcelorMittal Flat Carbon Europe S.A. reserves the right to change its product range at any time without prior notice.