| The use of welding five points for attention |
Effects of welding is up to our expectations, in addition to the welding torch, welding torch and welding operation, also plays a vital role in. Welding rod welding process as we need welding materials, the use of the process to be considered we introduce below five points for attention:
One, should not be placed directly in the electrode has heating box baking
Electrodes for use are necessary prior to baking, and drying the alkaline welding rod is placed in the temperature control at 100 degrees C. the heat-insulating barrel, with. Some unused alkaline electrode if placed in the air for long time, easily absorb moisture, but also to bake the next day. By removing the electrode internal moisture and water of crystallization, to guarantee the welding process combustion stability of the arc and the weld metal quality. But it is worth noting that the baking electrode, electrode electric thermostatic drying should be put in the gradually warming, not directly into the already warming box baking, especially for safekeeping serious damp electrode, because suddenly subjected to high temperature, moisture evaporation and late sudden expansion, so that the electrode's rupture.
Two, drying electrode is exposed in the air too long
After drying the electrode should be put in the oven or deposited on the electrode insulation cylinder with. If the electrode is exposed in the air drying and storing for a long time, electrode will quickly get damp, so that the electrode diffusion hydrogen content increased significantly, especially when exposed to air the first 1~ 2 hour moisture absorption is the fastest, the moisture absorption electrode for welding important structures, the welding quality of adverse effect of. So, in welding construction, the drying rods from the drying box is taken out, should be used up within 2 hours, for high strength steel, should be used up within 1 hours, or need to bake; or from the welding rod welding box is taken out, immediately placed into150 DEG C electrode insulation tube in heat storage, as used with the take, should not be stored in the open air for long time.
Three, restrictions on certain conditions and can not be cleaned of low carbon steel welding pieces, for the selection of basic electrode
Alkaline welding rod welding process of the poor, to rust, oil pollution, water sensitivity, the groove on the surface cleaning requirements are also higher, if welding cleaning is not thorough, easy produced during welding defects such as pores. Therefore, restrictions on certain conditions and can not be cleaned of low carbon steel welding pieces of the surface oxide skin, there is oil dirt, not to use the basic electrode. It should be the choice of welding technology and good welding, the welding of stomatal performance is good, to rust, dirt and moisture sensitivity is not strong.
Four, the impact toughness and crack resistance higher requirements to the important structural welding, for the selection of acid electrode
Acidic welding rod coating containing more oxide, oxidation resistance is strong, the weld metal with higher oxygen content, and the alloy elements larger burning loss. And in the coating of a large number of two oxidation of a portion of the silicon to silicon oxide inclusion in weld. Therefore, the weld of inferior mechanical properties, especially the plasticity and impact toughness is low alkaline welding rod. In addition, acidic welding rod coating does not contain fluorite, low ability to hydrogen. Weld metal hydrogen content is high, cold crack resistance is poor, and the weld in the desulfurizing element manganese content is low, the desulfurization effect difference. Therefore, the welding important structures for the selection of the welding, and should use the weld metal of a low oxygen content, alloy transition coefficient, sulphur and hydrogen content and low alkaline welding rod. The mechanical properties of weld metal and crack resistance are good than acid electrode.
The five, should not use carbon steel welding rod welding stainless steel welding.
Selection of carbon steel welding rod welding stainless steel, will make the stainless steel intergranular corrosion, intergranular corrosion of stainless steel by losing corrosion resistant ability, and under the action of stress rupture strength along the grain boundary, almost completely lost, is one of the most dangerous failure of stainless steel form. |
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