PQR for A36 to A27 Grade 65-35

By ScottF Date 05-13-2020 14:56

Good morning all,

I've been tasked with qualifying a procedure for welding A36 to A27 Grade 65-35. I'm familiar with (and only have access to) D1.1: 2015, D1.4: 2011, and D1.6: 2017.

What I know:
We're modifying castings by adding new base plates. The castings are essentially 8" x 8" tubes with 3/4" wall all around. The A36 plate is 1" thick and approximately 12" x 12".
The project manager want to use a 1/4" bevel with a 5/16" fillet cap, the casting is bearing weight perpendicularly in compression only, no other loads.
They both have similar mechanical properties: https://www.makeitfrom.com/compare/ASTM-A27-Cast-Carbon-Steel/ASTM-A36-SS400-S275-Structural-Carbon-Steel
-as well as chemical properties.

What I don't know:
What is the appropriate filler metal to use? I'm unable to find a [published] cross reference for this base metal combination. According to hobbyists and other welding forums, A27 welds similarly to most carbon steels with a variety of processes, e.g. ER70S-3 or-6 can be used with GMAW & GTAW, and ENiFe-CI with SMAW (Nickel 99 or Nickel 55, depending on machinability).
What code would satisfactorily guide me to qualifying a structurally sound weld with these two base metals? I've qualified unlisted base metals per D1.1 in the past, but I'm lost with respect to welding castings. Is it possible to qualify per D1.1? Would the cast steel hold up to the prescribed mechanical tests? Should there be preheat, PWHT, etc.?

I found an article in Welding Journal from 2015: https://www.sfsa.org/news/2015/Cast%20Carbon%20Steels%20in%20AWS%20D1.1.pdf
It concludes ASME Section IX (which both my company and I am completely unfamiliar with) allows it to be welded (prequalified) if a WPS was previously qualified with the same P-numbers. is ASME Section IX my only option?

What are your thoughts?

Thanks in advance.
-Scott

By 803056

Date 05-13-2020 18:57

E7018, E71T-1C, or ER70S-2 or 6 should work for your application. You could use a little preheat to make sure the steel is dry.

I'm not sure how you would qualify the WPS unless you could find a piece A27 cast as a plate.

Al

By ScottF Date 05-13-2020 19:48

We order the castings from the foundry, they also provide us with samples with MTR's, they can get us any shape we need. My main issue is how would I specify the mechanical tests? I'm looking for information comparable (if another code is better suited) to D1.1 Table 4.2, 4.5, and 4.11, as well as if the guided bent tests (radius, size of sample, etc.) are any different.