Can the welding procedure qualification for Q345qD replace that for Q345B?
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Dear experts, for ordinary structures, there is usually a welding procedure qualification for bridge girders using Q345qD material; the plate thickness in such cases is 16 mm. Now, we need to carry out a welding procedure qualification for construction machinery, using Q345B material with a plate thickness of 9 mm. I know that Q345D can be used as a substitute for Q345B, but I haven’t found any clear information regarding Q345qD. I’m really stuck and am seeking help earnestly~
:Lol, what criteria do you use for the evaluation?
The standard doesn’t matter; just focus on getting in touch with Q345qD
Finding a reasonable basis allows one to rely on it
Does the standard not matter? Well, it doesn’t matter whether it covers or not. . If it can be welded, then it’s fine.
It’s not that standards shouldn’t be used; rather, there are many standards available these days. One can use any standard – if someone wants to use a butt welding assessment report for Q345qD in place of one for Q345B, then there’s no need to use the Q345B standard. I’m not sure if this is acceptable. Is there any standard that specifies such a thing, or is there a way to prove it indirectly?
1. These 2 materials should be able to be classified in the same category and group. 2. For evaluations at 8 mm, the coverage over the base metal thickness is 8–16 mm. . If the evaluated value is 16 mm, then the thickness of the base material covered is 16–32 mm
According to NB/T 47014-2011 – Welding Procedure Qualification for Pressure Equipment, Table 7 in section P37 states that if the thickness of the test piece is between 10 and 20 mm, it can be increased to 5 mm to 2T. Is this understanding correct?
Another question: when joining Q235B with 16Mn, or Q235B with Q345B, is it necessary to conduct additional welding qualification tests? The joint thickness is 12 mm for Q345qD; all other conditions are the same
When the important variables remain unchanged, this does not require re-evaluation.
In 47014, when impact testing is required, the coverage area should be narrow. .