Out-of-line annealing means that the recrystallization annealing of hot or cold rolled steel plate is carried out in the bottom type annealing furnace or cover type annealing furnace before entering the hot plating wire line, so that there is no annealing process in the galvanized line. The steel plate must maintain a clean active surface of pure iron, free of oxides and other dirt, before hot dip galvanizing. In this method, the annealed surface oxide sheet is first removed by pickling method, and then coated with a layer of zinc chloride or a mixture of ammonium chloride and zinc chloride solvent for protection, so as to prevent the plate from being oxidized again.
If the zinc coating is good, but when the light comes out in 3% nitric acid, there is a dark shadow on the coating, and the film is brown when passivation occurs, which may be caused by foreign metal impurities such as copper or lead in the galvanized liquid. When there is a problem in the process of galvanizing, check the temperature and current density first, and then measure and adjust the content of zinc and sodium hydroxide in the bath through the analysis of the bath. Whether DPE levels are low can be determined by Hull cell test.
The construction of inner wall and outer wall steel wire mesh can effectively solve the wall cracks, falling off, empty drum phenomenon. Hot dip galvanized steel wire mesh material requirements: net surface leveling, width and length to meet the project required standards, welding process, weight, zinc, etc., with more production and operation, detection certificate is complete.
Large rolls of galvanized wire in oxygen violently extinguished, spark, and sodium block, magnesium strip in oxygen extinguished, no spark phenomenon. This phenomenon is determined by the composition of galvanized wire. The galvanized wire used in the experiment is pig iron or steel wire, pig iron and steel are iron and carbon alloy, containing iron and carbon two elements of complex material. Carbon in galvanized wire will produce carbon dioxide when extinguished, solid into gas, volume will shrink rapidly.
The electrode is a kind of material that the coating (that is, the coating) is uniformly and centrally applied on the welding core outside the metal welding core. The electrode is composed of two parts: the welding core and the coating. The welding core is the metal core of the electrode. In order to ensure the quality and performance of the weld, there are strict regulations on the content of various metal elements in the welding core. Electrode structure: portable non – electrode, including cylinder, tube, sleeve plug. The electrode is made of metal or metal oxide powder, such as high heat agent and additives. Paper tube is generally used for drug pipe, and metal tube can also be used for different welding parts and use environment. The plug is at the end of the electrode, which is the clamping part that matches the sleeve during welding and prevents the flux from leaking out of the tube.
Galvanized wire A stable layer of zinc is coated on the outside of the wire, which is used to protect the wire and make the wire service life longer. When producing galvanized wire, the wire is pickled. Pickling is to use some acid mist or acid to wash off some oxides on the surface of iron, that is, rust, and some other corrosive substances, to achieve the purpose of cleaning iron, so that zinc will fall off when galvanizing.
The quality of hot-dip galvanized barbed wire is only good in the surface of the wire attached to the galvanized layer, and with the chemical reaction, the surface of the zinc layer will gradually lose effect because of the oxidation reaction, this situation is more prominent in the humid area of the environment. And because after all, it is rusty iron wire, so the quality of hot-dip galvanized barbed rope is certainly not up to the level of stainless steel barbed rope.
Product features: strong structure, flat surface, with good corrosion resistance, oxidation resistance. The material of small hexagonal mesh is the same as that of other hexagonal mesh, which is generally made of low carbon steel wire, stainless steel wire and galvanized steel wire as raw materials by the hexagonal mesh machine.
In order to pack and bind galvanized wire in the surface of the sedimentary layer to local removal of surface film, surface inclusion and other defects can be found and treated by conventional technology; Excess foam is formed when soap and surfactants such as saponified fats are brought into the tank. Moderate rates of foam formation may be harmless. Small, homogeneous particles of large denier present in the bath can stabilize the foam layer. Use activated carbon mat to remove surface active substance. Or through filtration to make the foam is not too stable, which are effective measures; Other measures should also be taken to reduce the amount of surfactant introduced. The electroplating speed can be obviously reduced by the addition of organic matter. Although chemical formulations facilitate high deposition rates, the deposition of organic matter does not meet the requirements of coating thickness, so activated carbon can be used to treat the bath.
As we all know, the mechanism of resistance to atmospheric corrosion of zinc includes mechanical protection and electrochemical protection. Under the condition of atmospheric corrosion, there are ZnO, Zn(OH)2 and basic zinc carbonate protective film on the surface of zinc layer, which to a certain extent slows the corrosion of zinc. When this protective film (also known as white rust) is damaged, a new film will be formed.
