We've had our fun with the post, now it is time to offer some help to this poor soul.
I believe he is referring to the limitations placed on the thickness of the base metal or deposited weld metal when using GMAW in the short circuiting transfer mode. I could be wrong, it happen more often that I like, but never the less.
When qualifying a WPS using a coupon that is less than 1/2 inch (12 mm) thick, the maximum base metal thickness qualified is 1.1 times the thickness of the coupon. If the test coupon is more than 1/2 inch thick, the procedure is qualified for a base metal thickness of 2 times the coupon thickness.
Now remember, the applicable welding standard is ASME Section IX. What do the letters A, S, M, and E stand for? Always, Sometimes, Maybe, or Except. So, there is more than my short answer to the question, but it is a starting point for the conversation.
Best regards - Al
Al,
also, QW-403-6. says when performing a qualification that would include Charpy's then T (base metal thickness) is a supplementary essential variable where normally it would not be. Using an example of 1/4" base metal, QW-403-6 says that your min. T would be .250. But if you need to qualify down too, lets say to .125, then your coupon could be machined to .249 and your min. T now is .124.5.
Sorry for being a little off topic, but I'm going through both scenarios right now using the Miller RMD on a couple of compressor stations we are going to start work on for Trans-Canada. You have to be conscious of short circuit only allowing for 1.1 for certain thicknesses.
Jim
It would have been so much easier to respond had the original post actually asked a question. Then we would have a basis for responding rather than guessing what he was looking for.
Working with thin materials can also be a problem in that one would have to use subsized samples.
Best regards - Al
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