For ASME standards, lateral bending is not allowed when it is less than 10 mm; then how can the two welding methods be used for 8 mm?
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For ASME standards, lateral bending is not allowed when the thickness is less than 10 mm. Currently, there are two welding methods: TIG welding with a backing layer of 8 MM thick plate followed by welding with electrodes for the final coating. How should the bending test be conducted during evaluation? With methods that only involve bending the surface or the back, a certain type of bending is definitely missing in such welding techniques: TIG welding lacks surface bending, while stick welding lacks back bending. How should this be addressed? Is this considered qualified? Is there any basis for it?
According to ASME standards, side bending is not allowed if the plate thickness is less than 10 mm. Under these circumstances, for the two welding methods used for 8mm thick plates (TIG welding for the root pass and shielded metal arc welding for the overlay pass), only face bend and back bend tests can be conducted during evaluation. For TIG welding, only a back-bending test can be performed ； For electrode welding, only the face bend test can be performed. If either of these two welding methods fails to pass the specified bending test, then that welding method does not meet the requirements of ASME standards. For a qualified judgment, it is necessary to refer to specific ASME standards and sections, as well as the requirements outlined in the Welding Procedure Specification (WPS). If all other requirements regarding the performance of the welded joint specified in WPS are met, and the bending test can be passed, it can be considered acceptable; however, final confirmation is also required from a welding engineer or the relevant department. The absence of a warping test does not necessarily mean that the welding is defective; it mainly depends on whether other properties meet the standard requirements. .
This post was last edited by freemanxxg on 2024-5-25 at 15:53. Thank you for your reply; as you said, it shouldn’t be possible, as it’s not allowed by the rules. But what exactly should be done in this situation? Is there a way? Under normal circumstances, for a welding method, there are two specimens with back bending and two with face bending, for a total of 4 specimens. When side bending is used as an alternative, four specimens are still required. However, in the case of combined welds, the root pass cannot have face bending, and the cover pass cannot have back bending; it is therefore not possible to achieve both types of bending for each welding method. So how is bending carried out in such situations?
In the case of combined welds (such as TIG welding for the root layer and shielded metal arc welding for the cover layer), since each welding method applies to different areas of the weld, there is indeed a welding method for which a specific bending test cannot be carried out (TIG welding cannot be used for face bending, while shielded metal arc welding cannot be used for back bending). The approach in such cases is treated as a special case according to the regulations, and it is necessary to consider the requirements of the ASME standards and the Welding Procedure Specification (WPS). Generally, when it is not possible to carry out all the tests required by standards, a welding engineer or relevant technical personnel is needed to assess the welding quality based on the actual welding conditions and project requirements, and to make a comprehensive judgment on the suitability of the welded joint by combining it with other testing methods such as non-destructive testing. If all other tests and sample inspections meet the standard requirements, this welding method may be considered acceptable. However, whether it will be permitted in the end depends on the specific provisions of ASME and the WPS, as well as relevant technical decisions and approval processes. For reference only
For ASME standards, lateral bending is not allowed when it is less than 10 mm; then how can the two welding methods be used for 8 mm?