Consumable for S50200

[kclim]

Was hoping someone could recommend a welding consumable for welding S50200 plates (5Cr 0.5 Mo, ASTM A387, Grade 5 Class 1).

Stick or TIG consumable will do.

Also, I take it that PWHT will be unnecessary given the plates are under 6mm thick (single v-butt)?

Thanks

 

[metengr]

kclim
The welding consumable I would recommend is

SFA 5.5 E8018 B6 SMAW process for plates for higher deposition rate in comparison to GTAW.

Re; PWHT
The 5 Cr is an air hardenable steel and, as such, I would consider PWHT unless you can qualify a weld procedure on this thickness with elevated preheat and see if you can pass bend testing with no PWHT. It may be tough to do.

 

[kclim]

Thanks for the info metengr. Regarding the preheat - I've looked up our relevant standard (Australian) which suggests a preheat of 200ºC. In this case, what would you consider elevated - 250ºC?

 

[metengr]

kclim;
Elevated temperature would be more like 275 deg C for this material. You can try to use a temper bead approach for the 5Cr base material. The problem you may have is the ductility of the weld deposit and trying to pass bends. It is possible that if you go with a lower strength filler metal (under matching) and use a temper bead technique, you might be able to pass bend testing for this weld joint configuration and thickness. I would suggest using the GTAW process for improved toughness versus SMAW.

I would run a weld coupon per the above, and evaluate the results.