The welding core is the metal core of the electrode. In order to ensure the quality of the weld, there are strict regulations on the content of various metal elements in the weld core. In particular, there are strict restrictions on harmful impurities (such as sulfur and phosphorus), and the quality of the weld core metal should be better than that of the base metal. Arc welding cannot be carried out on a smooth rod without a coating. This is because the arc stability is very poor, splashing is very large, and the weld is not well formed. After long-term practice, it is gradually found that the performance of the electrode is greatly improved by coating the welding core with some mineral raw materials (i.e. electrode coating). (1) Ensure stable arc combustion, so that the welding process is normal. (2) Using the gas produced after the drug skin reaction, protect the arc and the molten pool, prevent the harmful gases in the air (such as nitrogen, oxygen, etc.) from invading the molten pool, such as these gases will cause cracks and pores in the welding material, so that the welding can not achieve the ideal effect. (3) After the drug skin is melted, slag is formed, which covers the weld surface to protect the weld metal, make the weld metal slowly cool, help the gas escape, prevent the generation of pores, and improve the structure and performance of the weld. (4) After melting, various metallurgical reactions will be carried out, such as deoxygenation, sulfur removal, phosphorus removal, etc., so as to improve weld quality and reduce alloying element burning loss.
Sodium and magnesium contain less combustible impurities, and when extinguished, they simply glow. Galvanizing belongs to the electrochemical processing process which is widely used on the surface of steel. So it is, first of all, because zinc coating (especially after supplementary processing, such as chromate treatment and phosphating) resistance to atmosphere and water is more stable, and the galvanized process itself this is cheaper and simple.
Iron and steel in the condition of cooling on the surface galvanized, and hot dip galvanized steel pipe in the condition of hot dip on the surface, its adhesion is strong, not easy to fall off, hot dip galvanized pipe although also rust phenomenon, but in a long period can meet the technical and sanitary requirements.
Galvanized wire can be used zincate galvanized or chloride galvanized and other processes, appropriate additives should be used to obtain the coating required by the standards of low carbon steel wire. When the galvanized wire out of light plating should be carried out light treatment, the galvanized wire bath to control the temperature. Now the quality level of galvanized wire on the market is not equal, galvanized wire is also called hot dip zinc and hot dip galvanized, is an effective way of metal corrosion prevention, mainly used in various industries of metal structure facilities.
The methods to control the thickness of galvanizing are as follows: you can slow down the lifting speed of the workpiece, control the time of galvanizing as far as possible, add the appropriate amount of thinning alloy, reduce the thickness, and improve the temperature of hot-dip galvanizing. But consider the zinc pot, iron pot should not exceed 480 degrees, ceramic pot can be 530 degrees, which can reduce the time of zinc immersion.
Hexagonal guardrail network custom corrosion lost the original characteristics, in the shape, color and mechanical properties will change, resulting in equipment damage, pipeline leakage, etc., specifically, it is easy to break, lose the original protection function.
