Problems with selecting electrodes for strong alkali pipeline welding?

What kind of welding material is used for pipelines generally has nothing to do with the medium. We generally use J422 electrodes when welding ordinary carbon steel pipes such as 20# steel. Never used J507. >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> The differences between the two types of welding rods checked on Baidu are as follows: The biggest difference between J507 welding rod and J422 welding rod is that: 1. The coating types of welding rods are different ； 2. Different intensity levels ； 3. The tensile strength, impact energy, and plastic toughness of the weld metal vary greatly. Under normal circumstances, J422 is used, but when the force is large, the restraint degree is large, or the dynamic load occurs, the matching alkaline electrode J427 can be used. It is not necessary to use J507. For welding carbon steel, the principle of selecting electrodes is equal strength. ； For workpieces that cool too quickly and have thin wall thickness, welding rods with a lower strength should be selected. ； On the contrary, the use of low-hydrogen welding rods should be considered. Especially when the pipeline is highly rigid and the working environment temperature is low, the choice of welding rods should be more careful. If it can meet the requirements, there is no need to use J507 welding rod. Because the 507 welding rod is an alkaline welding rod, and the dust generated during welding is heavier than J422, which has a greater impact on the operator's health, so it is most reasonable to use J422. From the application level: J507 welding rod requires the use of DC or inverter welding machines. It is usually used in structural welding of carbon steel that requires high strength levels, and its weldability is very good. J422 electrode can be used with both AC and DC welding machines, but arc deflection is prone to occur when using DC or inverter. Improper current selection can easily cause defects such as slag inclusion and incomplete penetration. It is generally used for welding ordinary steel structures and has no special requirements for strength. J507 is an alkaline drug peel, while J422 is an acidic drug peel. >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> Personally, I feel that the reason for the fracture of the welding joint may be the J507 electrode. It is also possible that there is a problem with the welder's level of welding.

The analysis on the second floor makes sense. I also know the difference between J422 and J507. This is not the main reason. There is no problem with the welder's level. Can it be analyzed from other aspects?