Q1: What is the cracking susceptibility of API 5L X80 welds?
A6: High due to alloy content; use ultra-low hydrogen processes, preheat to 100–150°C, and employ welding consumables with >80% joint strength matching.
Q2: How to test weld corrosion resistance for API 5L sour service pipes?
A7: Perform HIC (Hydrogen-Induced Cracking) and SSC (Sulfide Stress Cracking) tests per NACE TM0284/TM0177 on welded coupons.
Q3: What filler metal is used for welding A312 TP304L to carbon steel?
A8: Use ER309L filler for dissimilar welding to mitigate carbon migration and residual stress.
Q4: How to avoid sensitization in A312 TP316 welds?
A9: Use low heat input, TIG welding preferred, and consider stabilized grades (TP316Ti) or post-weld solution annealing.
Q5: What is the PWHT requirement for A312 TP321?
A10: Generally not required; but if PWHT is needed for stress relief, heat to 850–900°C followed by rapid cooling to prevent carbide precipitation.
