20 Issues in Welding Procedure Qualification

Are you just playing around with 20? Question: For steel grade 20, the options are Q345R and 20MnMo.

This post was last edited by wanlirn on 2023-7-7 at 16:46. It’s not possible; not to mention anything else, even the welding materials change. It’s not very reasonable to force the use of 550-grade electrodes to weld 500-grade workpieces

According to the provisions in 47014, important factors need to be considered in weld procedure qualification. If the evaluation results for Q370 and 20MnMo are already available, and the key factors remain unchanged, then they can be applied to the welding procedure qualification for Q345R and 20MnMo. It should be noted, however, that although the compositions of these two materials are similar, the specific welding process still needs to be determined based on actual conditions. It is recommended to refer to the welding specifications and the technical requirements of relevant materials, and to consider factors such as the physical and chemical properties of the materials as well as their weldability in order to assess the feasibility of the welding process. It is best to conduct tests and verifications during actual operations to ensure that the welding quality meets the standard requirements. .

This issue was finally resolved; the evaluation for Q370 and 20MnMo remains unchanged, and it can be applied to Q345R and 20MnMo as well. Individuals have different interpretations of the term “two categories (groups)” in clause 6.1.2.1e; it is believed that PQR F1.3+F3.2 meets the requirements, and that, with the important factors remaining unchanged, the WPS supported by this PQR are F1.3+F3.2, F1.3+F1.3, and F3.2+F3.2. It is now necessary to determine whether this PQR supports WPS F3.2+F1.2. Since changing from F1.3 to F1.2 does not comply with clauses b–d of the evaluation rules for category 6.1.2.2, it is determined that rule a should be applied: re-evaluation is required. I asked expert 47014 again yesterday, and the expert said that PQR F1.3+F3.2 is acceptable; when used separately for F1.3+F1.3 and F3.2+F3.2, the latter case presents problems. Therefore, the clause stating that \"the welding process, which has been found to be satisfactory after welding between materials of these two types (groups), is also applicable to welding these materials together individually\" was removed this time. Since F1.2 has a lower group number than F1.3, it can be applied provided that the evaluations of other important supplementary factors remain unchanged. . In fact, large companies do conduct evaluations; if the timeline permits, they charge a certain amount for such an evaluation, considering it as a form of technical investment. For pipe forgings, 16M is welded to the flange cover 20MnMO; when high restraint is present, 507 is a better choice. 16MN has good weldability and toughness, and there are no major issues with post-heating using J557 as well.

Many assessment methods can be used according to the assessment rules, but the actual circumstances must also be taken into account.

I guessed the beginning but not the ending. .

In your case, according to current standards, it cannot be covered