For your info, the heat treatment mentioned for this kind of material
it is not called normalising heat treatment but called solution heat
treatment.
What happens during this treatment (when performed well) is that all
kind of negative micro structural issues, such as Chromium Carbides
and Sigma Phase, will be dissolved in the material by which the base
materials corrosion resistance properties increases. After casting
this is required for most Stainless Steels and Duplex Stainless
Steels. At the foundry where I work we don't specify interpass
temperature during welding below 250 °C, which normally is required
for such materials, only because we always execute Solution Heat
Treatment in order to ensure that all undesirable structure contents
will be dissolved.
Best Regards,
Herman Pieper
On 17 jun, 06:35, hegde...@isgec.com wrote:
> > Dear Abhijeet
>
> Most of the welding consumables are developed to get properties in as
> welded or PWHT below AC1 and not PWHT above AC3 Therefore the component
> after welding should be used as welded or by PWHT such as Stress
> relieving.
> The moment you PWHT above AC3,causes deteoriation in weld properties.
> For Weld with normalistion require specially developed consumables with
> modification of weld chemistry.(Generally no body prefer)In such case the
> qualification of PQR shall be brand specified.This can be developed with
> trilas only.
> At Godrej steel foundry for different steel grade valves we never used to
> renormalise the casting after weld repair. (only SR)
>
> Regards
>
> Hegde P.B.
> 09714714803
>
> Dear Abhijit,
>
>
>
> > For CF8m Post weld heat treatment is not mandatory.
> > So you dont have have to worry.
> > I was with KSB Pumps(Valve division) for 8 years In QA Dept.
> > Muni
>
> > On Tue, Jun 2, 2009 at 8:55 AM, abbey kangale <abhian...@yahoo.com> wrote:
>
> >> Dear All
>
> >> I have case for CF8M casting for Valves as per B16.34 which involves
> >> welding for internal cage fittment and ...
> >> Foudry has done welding and then they carryout subsequent Heat Treatment
> >> 1070Deg cel.to satisfy CF8M heat treatment requirement.
>
> >> When we asked for WPS/PQR foundry has submitted WPS/PQR for welding
> >> without
> >> PWHT and PQR is qualified without Heat Treatment requirement and for
> >> which I
> >> had taken a objection .
>
> >> Can Group advise my objection rersolution and corrective action as
> >> casting
> >> are ready for valve asssembly for our project
>
> >> Abhijit
>
> >> ------------------------------
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