a) As far as practicable, the heat treatment is to be carried
out in a furnace. Where this is impracticable, and more
particularly in the case of welding on board, the treatment
is to be performed locally by heating uniformly a
circular strip, extending on at least 75 mm on both sides
of the welded joint; all precautions are to be taken to
permit accurate checking of the temperature and slow
cooling after treatment.
b) For austenitic and austenitic ferritic steels, post-weld
head treatment is generally not required.