Best Ref For Substituting 9018-B3H4R Rods For 9018-B3L 1

[racookpe1978]

What is the best reference to quote (for checking) to allow substituing 9018-B3H4R for 9018-B3L rods?

My sub-contractor wants to begin using his 9018-B3H4R rods when he runs out of his current lot of 9018-B3L rods. We are re-facing steam valve seating surfaces in the machine shop.

 

[metengr]

Review AWS SFA 5.5 for specific and correct information related to SMAW low alloy filler metal classes and designations. There is no 9018 B3L electrode designation because after PWHT it does not meet the 90 Ksi tensile strength requirement. Therefore, the correct designation is 8018 B3L. Make sure you understand this regarding service application.

The suffix for H4 refers to low hydrogen electrodes. This number refers to a maximum diffusible hydrogen content in the electrode from manufacture.

Read AWS SFA 5.5 specification.

 

[racookpe1978]

I'm glad you noticed the problem about the 9018 B3L, but I can only repeat what we read from the label on the rods in the first rod container. 8<)

Heat treatment (for this valve) is substituted by a 2 hour 600 degree H2 baking after baking. Base metal temp during welding is 450 F.

Again, thank you for the quick reply!
Robert

 

[metengr]

If you use the 9018 B3H4 weld rod, you can omit the post weld hydrogen bake out. This rod was supplied as low hydrogen electrode.

Regarding your substitution, the B3 versus the B3L will have higher elevated temperature strength because of the higher carbon content in B3 versus B3L. So, this substitution would br what you need to use for elevated temperature service of 2.25%Cr-1%Mo steel.

 

[racookpe1978]

OK.