Questions about Q345R
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This post was last edited by qzn165_WGZL on 2017-7-19 07:09; it is currently in the process of welding procedure qualification. For 4mm thick Q345R plates, the coverage of the base metal ranges from 2 to 8mm; however, such 4mm thick plates cannot be subjected to impact tests. If the plates are made as 6mm thick Q345R products, is it necessary to conduct another welding procedure qualification test that includes impact testing?
1 Follow the standard writing style. . . . This is not necessary. . Because it is not possible to take a sample in this case, so the impact test can be waived. It is merely this test item that has been exempted. . The coverage remains impact-resistant coverage. 2. Currently, many inspections require you to provide evidence; how can you prove that no impact test was conducted and that it can cover the entire area? . This is a dead loop. . There are too many experts. . To reduce disputes, when making the evaluation, use a thicker sheet to mill a 5.95mm plate; this is the way to do it. . If the flatness is well controlled, 5*10 impact specimens can be obtained. With this coverage, there will be no disputes. .
In fact, Q345R with a thickness of less than 8 mm is very rarely used in pressure vessels, so there is no need to consider it.
Interpretation of clause 6.1.5.2 of standard NB/T 47014: For specimens with a base metal thickness of less than 6 mm, if an impact test is required but it is not possible to prepare impact test samples, the impact test may be omitted; however, the minimum value for the base metal thickness range of the welded joint remains T/2. “The requirement to conduct impact toughness tests on welded parts refers to the following three situations: 1) When the safety technical specifications or product standards for pressure vessels require impact tests on welded joints ； 2) When the pressure vessel design documents or relevant technical documents require impact testing of weld joints ； 3) For the materials used in pressure vessel products, if the material standards require impact testing, then the welded joints must also undergo impact testing.
Ge Zhaowen mentioned in his lectures that using 4mm material can only cover a range of 2-4mm
I have also attended Mr. Ge’s lectures and had the fortune to consult him; for 4mm Q345R steel plates, the root cover thickness should be between 2 and 8mm.
:Lol, the expert’s lecture. . . . None of them are as good as standard text. . .