The electrode custody of the good or bad has a direct impact on the welding quality, in particular, pay special attention to work in the field. Each welder, curators and technical staff should be aware of the electrode storage, custody rules. Electrode and other coatings, in many cases will be destroyed: 1) Transport, handling, use damage; 2) immersed in water or moisture absorption; 3) the oil or other corrosive medium pollution.
1) Damage: Although the electrode in the general case of damage resistance to the outside world, but can not be ignored due to the custody of bad being damaged. The electrode is a ceramic product, he can not impact resistant as steel core, loading and unloading can not throw him. Cartons electrode can not be used can not be linked to handling. Certain models of electrode such as the special drying requirements of basic welding rod coatings more than the normal electrode to be handled with care.
2) to absorb moisture: too high moisture in the electrode coating contains very dangerous, because many workers do not understand the electrode is wet welding finished weld surface with the naked eye is not necessarily visible pores, but the X-ray inspection showing stomata. When welding rod factory, all of the electrode has a water content, which change according to the model of the electrode, the water content is normal, that is, the formation of pores with a water content of the safety factor, the quality of the weld has no effect. All have to electrodes in the air can absorb moisture and relative humidity of 90%, the welding rod coatings absorb water quickly, ordinary alkaline electrode exposed to a very serious day damp old, even a relative humidity of 70% coating moisture increased. only in the relative humidity of 40% or less, the electrode is long-term storage was not the first impact.
Due to the difference between day and night humidity, the moisture of the air in the morning it is easy to condense into dew, it is easy wet electrode packaging. Electrode stored for a long time, it is easy to damp, so it is best done first storage electrode first.
Under normal circumstances, the electrode from a plastic bag and carton packaging, in order to prevent moisture absorption in the electrode before use, can not be arbitrarily apart, as far as possible be done now with now demolished, there may be remaining after Welding Electrodesis then sealed.
Damp by the simple identification methods: (1) remove a few from different locations with the electrode with the electrode support between the thumb and index finger of both hands gently shaking, if the electrode is dry hard and brittle, metallic sound, if the electrode is damp sound blunt. Electrode is often in use for a variety of tests, the sound is different between dry and damp electrode, this can prevent the misuse of damp electrodes. (2) If the Aluminium Welding Electrode using some model of damp found a crack sound and stomatal, then we must consider the electrode whether drying, and then consider other reasons. (3) with damp electrode welding electrode water content is very high, and even can see the electrode surface water vapor issued, or when electrode welding a most electrode tail cracks exist.
Electrode of the storage
(1) all kinds of welding rod must be the classification of sub-grade piling up, to avoid confusion.
(2) The electrodes must be stored in a dry warehouse, it is recommended that the room temperature below 10 ° C, relative humidity less than 60%.
(3) various types of welding rod storage, high 300mm from the ground, away from the walls of 300mm or more storage, so as not to damp.
(4) electrode once the library the amount can not exceed two days the amount has been a library at the electrode, we must take good care of.
Electrode using the pre-drying and custody
(1) acid electrode is not sensitive to water, organic rutile type electrode can tolerate higher water content. According to the specific circumstances of the damp, drying at 70-150 ° for one hour, short storage time and good packing, generally from time to dry before use.
(2) basic low-hydrogen electrodes must be dried before use, to reduce the hydrogen content of the electrode, to prevent the pores, cracks and other defects, general drying temperature of 350 ° C for one hour. Not be in a furnace electrode suddenly placed in a sudden cooling in order to avoid skin dry. There are special requirements on the hydrogen content, drying temperature should be raised to 400-500 ° C, one to the amount of one hour. Drying the alkaline electrode is best placed in another temperature control 50-100 ° C and low temperature drying box, stored and used with the check.
(3) drying electrodes, each electrode can not be stacked too thick (typically 1-3) in order to avoid uneven heating in the electrode drying and moisture is not easy to exclude.
(4) open-air operation, overnight must electrode safekeeping, does not allow open storage should be stored constant temperature in the cold box, otherwise the next day must be re-dried before use.
Expired electrode processing
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 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.