Pre Heat for 1.25 Cr - 0.5 Mo
Pre Heat for 1.25 Cr - 0.5 Mo
(OP)
Dear all,
I wonder why we require pre heat arround 150 C when we weld P4 (for example A-387). Is there any metallurgy reason for it ?
I wonder why we require pre heat arround 150 C when we weld P4 (for example A-387). Is there any metallurgy reason for it ?





RE: Pre Heat for 1.25 Cr - 0.5 Mo
RE: Pre Heat for 1.25 Cr - 0.5 Mo
Additionally,
min. 250 deg.F (121 deg.C) may be applied when MSTS > 60 ksi or thickness > 1/2" and
min. 50 deg.F (10 deg.F) may be applied when MSTS </ 60 ksi and thickness </ 1/2".
----- in ASME Section VIII, Div.2, App. D-120
Thomas Eun
RE: Pre Heat for 1.25 Cr - 0.5 Mo
Thanks and regards
Sayee Prasad R
Ph: 0097143968906
Mob: 00971507682668
email: sayee_prasad@yahoo.com
If it moves, train it...if it doesn't move, calibrate it...if it isn't written down, it never happened!
RE: Pre Heat for 1.25 Cr - 0.5 Mo
RE: Pre Heat for 1.25 Cr - 0.5 Mo