API RP 581 - 3rd Ed.2016 - Add.2-2020 - Risk-Based Inspection Methodology

2-74 API RECOMMENDED PRACTICE 581
Table 11.2—Susceptibility to Cracking—PASCC
Operating Temperatures <427 °C (800 °F)
Susceptibility to Cracking As a Function of Heat Treatment
Material
Solution Annealed
(default)
Stabilized
Before Welding
Stabilized
After Welding
All regular 300 series SS and Alloys 600 and 800 Medium — —
H Grade 300 series SS High — —
L Grade 300 series SS Low — —
321 SS Medium Medium Low
347 SS, Alloy 20, Alloy 625,
all austenitic weld overlay
Low Low Low
Operating Temperatures ≥427 °C (800 °F)
Susceptibility to Cracking As a Function of Heat Treatment
Material
Solution Annealed
(default)
Stabilized
Before Welding
Stabilized
After Welding
All regular 300 series SS and Alloys 600 and 800 High — —
H Grade 300 series SS High — —
L Grade 300 series SS Medium — —
321 SS High High Low
347 SS, Alloy 20, Alloy 625,
all austenitic weld overlay
Medium Low Low
NOTE If the process operating temperature is less than 427 °C (800 °F), then sensitization is present in the as-welded condition
only. If the process operating temperature is greater than or equal to 427 °C (800 °F), then sensitization can occur during operation.
Table 11.3—Determination of Severity Index—PASCC
Susceptibility
Severity Index—S VI
High 5000
Medium 500
Low 50
None 0