Outdoor sculpture

Virginia Costa <virginia.costa [at] gmail__com> writes

>Mark Anderson <manderson [at] wdm__ca> writes
>
>
>>The question posed were: was the material used not a high quality
>>stainless steel as it is already starting to rust as not every sheet
>>of steel used has rust on it (thus resulting in the artist to be
>>brought in to do some work) ...
>
>If the above cited conditions (composition, but also smoothness and
>cleanness) are not respected corrosion will not be prevented;
>anyway, concerning the type of steel used, you can start using a
>magnet: the lowest quality steels (but yet stainless!) are magnetic
>and maybe further send to analysis;

I absolutely agree with Virginia's answer, except for one minor
remark: While this is true in most cases for the main types of
stainless steels (SS), ferritic and martensitic SS (magnetic) are
usually less corrosion resistant than austenitic SS (non-magnetic)
there are some exceptions. Duplex and superduplex SS, which are
slightly magnetic, have in most cases higher corrosion resistance
than the common austenitic SS. And superferritic SS, with Cr
contents up to 30%, also have a superior resistance.

Having said that, it is true that those SS are used only for very
specialized applications, since they are not widely available and
are quite expensive. So the odds of finding a sculpture made in
those materials are almost close to zero. Bur artists, in some
cases, can be quite whimsical with the selection of materials for
their works.

Emilio Cano
Conservation Scientist
Centro Nacional de Investigaciones Metalurgicas (CENIM)-CSIC
Madrid, Spain


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                  Conservation DistList Instance 24:20
                Distributed: Wednesday, October 13, 2010
                       Message Id: cdl-24-20-005
                                  ***