The issue of welding joint coefficients
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For welds that are 100% inspected using RT, are fully welded by SMAW, and feature single-sided welding with double-sided formation (the back side is not fully cleaned; no further treatment is applied), what value should be used for the weld joint coefficient in such cases? In other words, with full SMAW welding and single-sided welding for double-sided formation, can it be assumed that full penetration can be achieved provided the welder’s skill level is adequate? Thank you for your advice~~~
In my opinion, it is difficult to ensure that there are no defects at the root of welds made using full SMAW welding, and it is also hard to guarantee complete penetration. For 100% RT inspections, the weld coefficient should be set at a maximum of 0.9 according to GB150. It is best to perform root cleaning on the reverse side or use GTAW welding. I’m not very good at welding; please feel free to point out any mistakes
I also think it won’t be possible; one can start with GTAW for the base layer and then use SMAW, which should ensure full penetration. No, let’s try conducting a SMAW type test
According to GB150, single-sided welding with double-sided formation is only permissible when TIG welding is used for the root pass
There are several cases: 1. As mentioned by the original poster, 0.85 should be used； 2. TIG welding for root pass: 100% RT grade II compliance; all other welds also achieve full penetration with 100% RT grade II compliance, so a score of 1 can be assigned. Personal opinion.
The weld coefficient for containers depends on the longitudinal welds; a 100% RT grade II pass for full penetration is required, so the value 1 is used
Personal opinion: It meets the 100% RT Class II requirements; the welding factor should be set at 1.0
If single-sided welding with double-sided formation can be achieved, then 100% RT can be used, and the weld joint factor can be set at 1. The problem is that single-sided welding with double-sided formation in shielded metal arc welding is difficult to achieve in actual welding processes! Argon arc welding is generally used for the root pass, as it makes it easier to achieve the desired result! ! !
It should be possible; our company has process evaluation support available. I personally think the weld coefficient should be set to 1.
Note: What was asked is, assuming that the welder has the necessary skills – isn’t there an option for single-sided welding with double-sided completion when obtaining a manual welding certificate? ). I guess the original poster is discussing an abstract issue, rather than something related to actual manufacturing? I think it’s fine, as long as the flaw detection is successful. The welding coefficient should be taken as 1.0.
Personal opinion: Single-sided welding with double-sided formation is only applicable when GMAW is used for the root pass or welding shims are employed; in such cases, the welding coefficient should be set at 1.
100% RT; here the welding coefficient should be taken as 1.0, as it is difficult to achieve double-sided formation with SMAW welding on just one side
The weld coefficient should be taken as 0.9.
Your welding method is standard single-sided welding. The single-sided welding with double-sided formation process involves creating a groove on only one side of the plate; welding is first carried out on that side to form the desired shape, after which the back side is cleaned using air gouging before welding is performed again to complete the formation. It is necessary to achieve formation on both sides. In fact, this process is quite similar to double-sided welding; therefore, GB150 classifies it as single-sided welding with double-sided formation, which is equivalent to double-sided welding. This process certainly allows for good penetration; it’s incorrect not to ensure complete cleaning on the reverse side.
Thank you all for your comments. There was mainly a disagreement with the designers; they believed that a coefficient of 1 could be achieved, but I personally prefer 0.9. For welds that cannot be welded on both sides (where it’s not possible to clean the back side), I think GTAW should be used as the base welding method. This post was last edited by Guofeng on 2009-3-31 at 17:20.]