Indaten® 355A

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 effectiveness 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.

Since 1 July 2013, the Construction Products Regulation (Regulation (EU) No. 305/2011 – CPR) has required that CE marking be affixed to all products delivered in accordance with a harmonised standard (e.g. EN 10025). This CE marking guarantees, for the uses defined in the standard, the properties described in the declaration of performance submitted by the manufacturer.

The corresponding declarations of performance are available on our website at: http://dop.arcelormittal.net/index.php

The above chemical properties are based on cast analysis data.

Galvanisation: No

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

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

Please reefer to the figures on the rigth side of the page.

The grade as per EN 10025-5 can be supplied:

Without any special rolling and/or heat treatment requirements. The abbreviated designation of this delivery condition is +AR. Following a rolling process in which final forming is carried out within a certain temperature range, producing a material in a condition equivalent to that obtained after normalising, with the result that the specified mechanical properties values are conserved even after normalising treatment. The abbreviated designation of this delivery condition is +N.

Furthermore, option 11c of EN 10025-5 is also available (sheet, plate, strip, wide flats and flats (width < 150 mm) with a nominal thickness ≤ 20 mm shall be suitable for flanging without cracking).

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.

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

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.

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.

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.