I have to take a 3g&4g 1/2" plate test (with backing plate) mild steel to stainless using E-309 My friend who is on site told me that all 3 plates are mild steel??? Is this correct? I have been practicing using the same set-up my friend described with little success. The weld is solid, but when I bend the coupons the mild steel tears away at the V-grove as if there is no penetration between the dissimilar metals. I have tried changing my amps-60 to 70 for 3/32" rod. I have also changed my puddle tie in etc... Should not the plates be both mild steel and stainless for this test? Any and all help is GREATLY appreciated. I have to take the test on 3-16-09.
I don't see welding mild to stainless being a good idea. If I remember correctly, my box of E308 says using 35-50 amps.
If all 3 plates are mild steel then why would you use an alloy electrode?
Using Carbon Steel for qualification to use Stainless electrodes is allowed by ASME Sec IX. Have taken a few 6G tests with GTAW roots and SMAW fill and cap with no issues. I'm sure the amount of dilution from the base metal can affect the properties some. And a root would be an area in which dilution is greatest.
If the plates are thick enough, maybe try side bends and see if the results vary. Also if using backing, try increasing the root opening or instead of a backing strip, back weld.
The reason that CS is allowed because with ASME, there is an allowance for using P1 (Carbon Steel) to qualify on P1 thru P11, P34 and P4X (Nickel Alloys).
On 1/2" seems 3/32" is pretty small, Can you go to 1/8" or 5/32""? Rods kept in oven?
Tom
You don't want to keep SS rods in an oven the flux will fall off.
Jeremy, I'm pretty sure that E3XX is still considered low-hydrogen and does require oven storage. Its just a little lower temperature in some cases. Check the manufacturers recommendations.
The 309 is designed for dissimilar welding of SS to CS with good mechanical properties. A lot of folks see the huge slag pile while they are welding and tend to run too fast causing the weld pool to sag/run to the center of a vertical weld.
Good Luck
I used sanvick rods and they require 300 degee storage
Tom
What are you using to bend the straps?
Are you using the correct test jig and radius?
With 3/32" SS stick rods, if your amps are too high your rod will be unusable with 1/2" to 1/3" of the rod left. So turn amps down if that is happening. Be sure to remove all slag during the test. Some brands weld better than others but lots of grinding is often part of SS stick test.
SS coupons are very expensive and not always required for certification. So CS coupons are much more common when allowed.
309L 3/32" stick rods are between 70-85 amps, depending on welder. If the slag isn't popping off by itself it isn't hot enough. Keep your mouth shut and shirt buttoned up the slag hurts. Make sure to clean every pass, no slag and no smoke.
they require 150 degree ovenb after opening. They will draw moisture causing porosity.
Forum
