Process qualification uses HJ431; can SJ101 be used for the containers?
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Previously, HJ431 was used for the submerged arc welding qualification tests; now that the flux used has been changed to SJ101, is it necessary to conduct new qualification tests?
NB/T47014-2011 6.1.3.3: When performing submerged arc multi-layer welding on Fe-1 class steel, changing the type of flux (neutral flux, active flux) requires re-conducting a welding procedure qualification.
Take a look at clause 6.1.3.3 of NB/T47014-2011.
Both the material sheets for HJ431 and those for SJ101 clearly state that it is a neutral flux. According to clause 6.1.3.3 of NB/T47014-2011, it is clear that no additional welding process evaluation is required. Don’t listen to people’s nonsense.
If the base material remains unchanged or is within the same group, no evaluation is required as long as the type of weld metal resulting from the use of flux SJ101 with the wire is in the same category as that resulting from the use of flux HJ431 with the wire, or if the type of weld metal produced by SJ101 is of a higher grade than that produced by HJ431. According to NB/T47014, for example, in the following case: Q345R/16mm/butt weld/AW/SAW/F5A0-H10Mn2 (HJ350–neutral flux)/qualified in impact tests at 0°C, can the welding process evaluation be applied to Q345R/16mm/butt weld/AW/SAW/F5A2-H10Mn2 (SJ101–neutral flux)/impact tests at -20°C, provided that the important factors and additional factors related to other general and specific welding evaluation criteria remain unchanged? Why? Answer: Applicable. Reason ①: Because neither the category number nor the group number of the base material has changed ； ②The welding materials F5A0-H10Mn2 (H10Mn2+HJ350) and F5A2-H10Mn2 (H10Mn2+SJ101) belong to the same category codes (FeMS-1-2, FeG-2); therefore, the category codes of these welding materials remain unchanged. Moreover, both HJ350 and SJ101 belong to neutral fluxes.
6.1.3.3 What does neutrality mean? Is the pH level neutral? Is the infiltrated alloy neutral? Please have some experts clarify these matters first before teaching others, so as to avoid causing harm.