The so-called "expired" does not refer to the storage time exceeds a certain time limit, but rather refers to the quality of different levels of change (deterioration). Various types of electrodes longer storage time, and sometimes in the white crystalline (scared) This is usually caused by the water glass electrode surface, the crystallization is not harmful, it means that the electrode storage time is very long and wet performance.
1, should be stored for many years the electrode process test electrode according to the specified temperature for drying. Welding did not find abnormal changes in the electrode process performance, such as drug leather successful block off phenomenon, as well as pores, cracks and other defects, the electrodes mechanical properties are generally guaranteed.
2, the Welding Electrode due to damp welding core minor rust, and basically does not affect performance, but if the high quality of welding, it should not be used.
3, the electrode damp rust is severe, the discretion to downgrade to use or be used for general component soldering. The best national standards to test the mechanical properties, and then determine the scope of its application.
4, if the welding paint contains a large number of iron and hydrogen content in the high relative humidity and longer storage time, electrode damp serious, even paint, corrosion, electrode drying, welding, continues to generate pores or spread high, and thus have to be scrapped. Required to improve the packaging to prevent electrode to absorb moisture in storage must be properly kept.
5, the Welding Materials of various types of serious deterioration, drug skin has been seriously off phenomenon, this batch of welding rod should be scrapped.