Emergency help! Stress corrosion!

Thread Content

:L designed the tower shell to be made of 20R+0Cr13 composite material, while the nozzles were intended to be made of 0Cr13 material. However, the manufacturer could not obtain pipes made of 0Cr13, so pipes made of 0Cr18Ni9 were used as a substitute. Due to a lack of careful consideration at the time, this was accepted; later it was discovered that, because the medium contained wet H2S, these pipes no longer meet requirement No. 7 for welding! How can this problem be solved? 1. Wet H2S stress corrosion – Welding requirements • 1) Conduct process qualification ； • 2) Use welding materials of low strength as much as possible ； • 3) Limit the hardness of the welded joint ； • 4) Before heat treatment, the arc initiation and striking points shall be ground to a depth of over 0.3 mm, and the surface shall pass inspection ； • 5) Hardness testing of the welds on the process evaluation test plates shall be conducted on the side in contact with the medium ； • 6) Welded joints must not have any enclosed voids in them; if necessary, exhaust vents should be provided ； • 7) Welding of different types of steel, such as ferritic steel and austenitic steel, is not permitted.