Method of manufacture, Heat treatment and Marking
||(i) The cold drawn seamless
carbon steel pipes and welded carbon steel pipes shall
be supplied in normalised condition
(ii) Hot finished seamless carbon steel pipes shall be
supplied in hot finished condition or in normalised condition
at the option of the manufacturer.
(iii) The seamless alloy steel pipe either cold finished
or hot finished and welded pipes shall be supplied in
normalised and tempered condition.
(iv) By agreement between the users and the manufacturer,
the pipes may be delivered in a condition other than normalised
and tempered condition in which case they shall be suitable
for subsequent manipulation and the user shall be informed
of the heat-treatment necessary to give required properties.
||(i) Pipe bending and forming
(viz. reducing/swaging) operation shall be done by any
hot or cold method and to any radius which shall result
in a surface free from cracks, buckles or other defects
as determined by the method of inspection specified in
the design. A post bending or post forming heat-treatment
for carbon steel material is required with a nominal wall
thickness in excess of 19.0 millimetres unless the bending
or forming operation are performed and completed at normalizing
temperatures, where no further heat treatment is required.
The heat treatment where required shall be normalized
or stress-relieved, as the case may be.
(ii) A post bending or post forming heat treatment shall
be required for all ferritic alloy steel material with
nominal pipe size 100.00 millimetres and larger or with
a nominal thickness 13.0 millimetres or greater.
(iii) If hot bending or forming is performed, the material
shall receive normalize and temper or tempering heat-treatment
as required by the design. For cold operation, tempering
heat-treatment shall be applied.
|| Marking:-Marking shall be
carried out in accordance with regulation