dissimilar metals

[chtimi]

We have to do a weld procedure qualification according to ASME IX: A352 LCC with A pipe 316L.For that, we think that we can find a pipe with similar grade as ASTM A333 Gr6.ASTM A 333Gr 6 is for low T°,and we have a weld with different PNbs 1 groupe 2 and 8 groupe 1, we think we can use a rod for the root and an electrode for following layers , material type SFA 5.4 or 5.9 E 309L AND er 309L which are normally ok for welding carbon steel and 316L.The Probleme is we have to do impact tests according ASME ( - 45°C), and rod and electrode 309L have not impact tests in the material data sheet and pipe are 21.3mm * 2.77mm with 2.77mm thickness we can't do samples for impact test.
Please could you help us and give the way.
regards

 

[stanweld]

Impact test qualification per B31.3 is required of the HAZ of the A-333 Gr 6. The weld metal need not be tested if it conforms to 323.2.2 (f) (2). 316 L is exempt at -45C. You can also qualify on P1 Gr 2 plate materials in the 3G up position to meet Section IX requirements.

 

[stanweld]

By the way, 333 GR 6 is P1 Gr1 and may not be used to qualify the procedure for welding to 352 LCC, which is P1 Gr 2. SA-516 70 should be available with suitable impact test certifications to permit qualification.

 

[metengr]

Which standard are you working under for your piping system? The weld filler metal selection is fine, SFA 5.9 ER309 for the root and hot pass, and SFA 5.4 E309 for the fill. You need to obtain a copy of the ASME Boiler and Pressure Vessel Code, Section IX. Review Article II in Section IX, and follow the essential and supplementary essential welding requirements for GTAW and SMAW procedure qualification in accordance with QW-253.

Your coupon for weld procedure qualification can be performed on plate using a single vee groove following the guidelines in Article IV, QW- 451.1, and QW-462. Since the supplementary essential welding requirements will apply for impact testing, you need to obtain material that is of the same P No or S No and Group No as A352 LCC.

You will need to establish impact testing requirements for the weld metal and/or heat affected zone from either ASME B&PV code or some other ANSI/ASME standard that applies to your piping system.