Microscopic examination and corrosion tests are only necessary when
client require such as supplement requirement in the purchase order,
otherwise you may calculate corrosion resitance by chemical
composition.Especially sigma phase normally reduce impact strength of
the material so when PQR does met the requirements you may believe
that no or only small sigma phase was present in the test weld. When
approved PQR and WPQ is present by which the repair weld is madeas
layed down in the WPS based on the mentioned PQR you should say that
you cover any problems. Important is proper control of heat imput and
interpass temparature during repair welding. Also important is if any
solution heat treatment will be executed afterwards and if this is
also mentioned on the PQR. This of course is depending on if the
casting is still in the as casted condition or already machined,
because water quenching can influence dimensions. Depending on the
size of the casting (if large than will be expensive) you may perform
microscopic surface examination afterwards in order to prove that
there is no or acceptable level of sigma phase and / or replica
examination to qualify the level of intermetallic phases. You may also
perform measurements with ferritescope in order to measure ferrite
content.
Best regards,
herman Pieper
On 23 feb, 18:45, rutvik dixit <rutvikdi...@yahoo.co.in> wrote:
> Hi everyone,
> I need to inspect the castings of ASTM A 995 GR.4A(DSS). Now mfr. is having the approved/qualified wps for repair work. This material(castings) is having other requirements like ferrite content, pitting corrosion resistant test, sigma phase, total of intermetallic phases. The qualified wps doesn't consist these metallurgical tests, but having all mechanical and impact test. can mfr. go ahead with this wps for repair work? wps is having any relationship with these type of metallurgical tests?
>
> With regards,
> Rutvik
>
> The INTERNET now has a personality. YOURS! See your Yahoo! Homepage.http://in.yahoo.com/
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