SS Chemical Composition
Srinivasa Rao
CSWIP 3.2.2, NACE LEVEL II, ISO 9001:2015 Certified Lead Auditor, PCN MT, PT, LEVEL II, BOSIET plus EBS with valid Offshore medical (OGUK). Panama Seaman.
SS Chemical Composition
SA 312 TP 304: 18 Cr, 8 Nickel
309: 23 Cr, 12 Nickel
316: 16 Cr, 12 Nickel, 2 Moly
321: 18 Cr, 10 Nickel, Titanium
347: 18 Cr, 10 Nickel, Columbium
Low Alloy Steel
P No 4 - SA 335 P11: 1.25 Cr, 0.5 Mo
P No 5A - SA 335 P22: 2.25 Cr, 1 Mo
P No 5B - SA 335 P5C: 5 Cr, 0.5 Mo, Titanium
P No 5B - SA 335 P5B: 5 Cr, 0.5 Mo, Si
P No 5B - SA 335 P9: 9 Cr, 1 Mo
P No 15E - A/SA P91: 9 Cr, 1 Mo, V
Do SS need Preheat?
No!
Why?
Preheating steel slows the cooling rate in the weld and HAZ to avoid cracking.
The need for preheat increases with carbon content of steel, weld restraint, and thickness of steel.