I have to take a 3g 4g 1/2" plate test (with back strip) using E-309 rod. A friend who is already on site said that all three plates are mild steel?? Is this correct for this type of test? I have been practicing with the E-309 with little success. The weld area is solid, but when bent, the mild steel tears away right at the V-grove like there is zero penetration between the dissimilar metals. I have tried lowering amps/raising amps, changing puddle tie in position etc... Should not the plates for this test be made up of both stainless and mild steel. If not what amps should I run at? Should the steel be preheated? etc... I take the test on 3-16-09 any and all help is GREATLY appreciated!!!
The test is smaw using E-309-16. I am not sure what the code is until I get on site. I called my friend again today and he verified that all three plates are mild steel.
While I was active duty, I always tested out on mild steel. 7018, 8018, 11018, 12018, 308, 309, 315, 316, it didn't matter because our military standard requires qualification to the filler, not the base metal.
While I won't go as far as to say that it is common practice to substitute carbon steel for stainless steel for the welder performance test, it is done and permitted by ASME Section IX.
I prefer to use the same materials that will be used in production because most welders will agree that carbon steel and austenitic stainless steel are different critters and they don't wet the same while welding. The thermal conductivity is different, so they responds to heat differently. While some codes allow the substitution, I don't as a rule substitute one base metal for another.
Some companies pinch pennies and throw away dollars. I believe this is the case when a company tries to save a few dollars on test coupons, but spend endless hours repairing welds deposited by welders that should have been vetted by a sound welder performance testing program. It's easier and more cost efficient to address deficient skills in the test booth than it is on the job site.
I've had a problem with welders passing a simple T-fillet break test using E309-16 and E309-17. Neither electrodes were able to get fusion to the root. A change to E309-15 solved the problem. This has happened on several projects involving austenitic stainless steels. I now require the root pass to be welded with EXXX-15 for all fillet welds in austenitic stainless steels (when I have input) and for the most part, it has proven to be successful in getting fusion to the root (but very little past the root). I'm a big believer in the T-fillet break test when evaluating a welder's skills. It is fast and economical.
That was the hardest hump for me to get over in transitioning out of the Navy and learning to weld to AWS. I never did see much sense in qualifying on mild steel, personally, and can remember questioning my instructor in weld school about it. Something to the effect that if I am going to be welding on stainless, why would I test out on carbon? It may well be that the intent is to save a few bucks here and there.
It sounds like your testing will be done to ASME IX. It is very common to weld carbon steel test plates with 309L filler to qualify both carbon to stainless (P1 to P8) and stainless to stainless (P8 to P8).
I'm wondering if your practice plates are cut so that the plate rolling direction is parallel to the plate width? If not, you are bending "against the grain". (Ie: a 7" wide flat bar cut to 3" long would be OK but a 3" wide flat bar cut to 7" long would not.)
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