1, the electrode should not be placed directly inside the baking has been warming
Electrode prior to use to make the necessary baking, make the basic electrode by drying at 100 ℃ temperature control on the insulation barrel, used with the check. Some, if not run out of basic Types Of Welding Electrode placed in the air a long time, easy to absorb moisture, but also to re-bake the next day. Internal electrode by removing the water and crystal water, in order to ensure stable burning arc welding process and the quality of the weld metal.
But it is worth noting that baking electrode, the electrode should be placed within the electric oven is gradually warming up, not directly into the baking chamber has been heating up, especially because of improper care and excessive moisture of the electrode, the high temperature due to sudden , the sudden expansion of the water time to evaporate so the skin electrode drugs rupture.
2, the drying of the electrode should not be exposed to air too long
After drying the electrode should be placed or stored in a dry box insulation barrel electrode used with the check. If the drying of the electrode exposed to air too long storage time, electrode drugs will rapidly damp skin, so skin electrodes drug diffusible hydrogen content increased significantly, particularly exposed to the air in the first 1 to 2 hours to absorb moisture the fastest, will this moisture absorption of important structures for welding electrodes, welding will adversely affect the quality. Therefore, in the welding construction, the drying of the electrodes removed from the dry box, should be used within 2 hours for high strength steel welding rod should be used within one hour, or need to re-baked; or electrode from Remove the electrode box immediately after the electrode into the insulation tube 150 ℃ in the heat storage, used with the check, should not be stored in the open for too long.
3, subject to certain conditions and can not clean up low-carbon steel weldment, should not use alkaline electrode
Basic electrode welding process is poor, of rust, oil, moisture sensitivity, on the groove surface cleaning requirements are higher, if the weldment is not completely clear, it is easy in the welding process produces porosity and other defects. Therefore, subject to certain conditions and can not clean the surface of low carbon steel weldment there oxide, oil and other dirt when not to use alkaline electrode. The welding process should be used electrodes of good acidity, anti acidic pore electrode performance of rust, oil and moisture sensitivity is not strong.
4, the impact toughness and crack resistance for demanding major structural welding, the electrode should not use acidic
Electrode in acidic drug skin contains more oxides, oxide is strong, more weld metal oxygen content, while burning a greater alloying elements. Skin and in the drug as part of a large number of silicon dioxide to form silicon oxide inclusions present in the weld, and therefore, poor mechanical properties of the weld, especially plasticity and toughness lower than the basic electrode. In addition, the skin does not contain acidic drug electrode fluorite (CaF2), dehydroepiandrosterone capacity is low; high hydrogen content of weld metal, poor resistance to cold cracking; and weld the elements manganese content is low desulfurization, desulfurization poor results. Therefore, the thermal cracking is also poor. Therefore, important structural Copper Welding Electrode should not use acidic, while the oxygen content of weld metal should be used in low alloy transition coefficient, sulfur content and low amount of alkaline hydrogen electrode. The weld metal mechanical properties and crack resistance than acidic electrode well.
5, should not use carbon steel electrode welding of stainless steel weldments
Good weldability of austenitic stainless steel, welding processes generally do not need to take special measures. However, if the electrodes selected properly, will produce a number of welding defects. For example, carbon steel electrode welding stainless steel, stainless steel will produce intergranular corrosion, intergranular corrosion of stainless steel by the loss of the ability of anti-corrosion, and will be under stress along the grain boundary fracture strength almost completely lost, the austenite Stainless steel forms the most dangerous form of damage.
Because carbon is caused by intergranular corrosion of the main elements, and therefore, should be low carbon stainless steels or ultra-low carbon stainless steel electrode, such as the Olympic 102, Olympic 132, Olympic 002 other electrode.