Goodmorning.
Coluld you tell me which is the difference between SA516 gr.70 and SA516 gr.70N?
Thank you

N is used to mean Normalized.
Normalizing is heating at 920 °C approx. to full austenitizing the steel and then cooling in still air.
Mauro

If the plate material specified to SA516,70 (without normalized), but the actual used plate is normalized then will it still comply to code?

dear friend,

i cant understand what u r saying pl. define.

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Regards,

M.KASI

If the plate material specified to SA516,70 (without normalized), but the actual used plate is normalized then will it still comply to code?

yes.
It is a mandatory requirement of the Code (Section II Part A) that the plate SA-516 shall be normallized if thickness is over 40 mm otherwise it is an additional requirement for less than or equal to 40 mm.

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Thanks & Regards,
Nasir
Welding Engineer
DESCON Engineering Limited.
Lahore, Pakistan.
Mobile # 0092-336-4145402

A) Normalising is not mandatory till 40 mm . It is a supplementary condition to be specified by Purchaser . When Normalising is not specified for lower thicknesses , both SA 516 Gr70 & SA 516 Gr70N meet the specifications.

B) Having said that , there is a difference in Impact test requirements. Ref UCS-66 . Normalised Grade 70 falls in Curve D where as Not - Normalised Grade falls in Curve B . For Impact test exemption ,see also
UG-20(f) -(up to 25 mm) & UCS-68(c) -up to 38 mm .

C) Fabricator can normalise the plate - UG-85 & UCS-85 apply.

D) Code does not specify single temperature for Normalising .
It is defined as "Heating above Upper Transformation Temperature and cooling in still air " Normalising temperature varies with carbon content and is left for fabricator to decide.

With regards
Rathnam