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) The electrode should be stored for many years the testing process, the 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.

Electrode (2) slight rust damp welding core, basically does not affect performance, but if the requirements of the Welding Electrode  quality, it should not be used.

(3) 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 welding paint contains large amounts of iron, the pores or diffusion of hydrogen in high relative humidity and longer storage time, electrode damp serious, even in the paint, corrosion phenomena, such electrodes are dried, welding still The content is very high, and therefore have to be scrapped. Required to improve the packaging to prevent electrode to absorb moisture in storage must be properly kept.

(5) serious deterioration of the various types of electrodes, drugs approved has been a serious shedding phenomenon, this batch of Welding Rod should be scrapped