4ft ironing board cover_black and white iron board cover

If the zinc coating is good, but in 3% nitric acid when the light, the coating has dark shadow, passivation occurs when the film is brown, may be caused by foreign metal impurities such as copper or lead in the galvanizing liquid. When problems occur in the process of galvanizing large coil galvanized wire, the temperature and current density are checked first, and then the content of zinc and sodium hydroxide in the plating solution is measured and adjusted through the analysis of the plating solution. Whether DPE content is low can be determined by hull cell test.

The life of the “wire”, is actually “low carbon steel wire”, carbon content in less than 0.2%. The surface is usually coated with zinc plating because it is easy to rust. Under atmospheric conditions, the galvanized layer will not rust before most of the fall off, relatively soft. The life of the “steel wire”, is carbon content in about 0.6% of the “carbon steel wire”, or carbon content in about 0.8% of the “high carbon steel wire”, they have enough hardness and elasticity after appropriate heat treatment, high strength. Uses such as winding ordinary spring and so on.

Hot dip galvanizing is then oiled and chromed. The quality of hot-galvanized sheet produced by this method is significantly improved compared with that by wet galvanizing method. It is only valuable for small-scale production. Continuous galvanizing production line includes a series of pretreatment procedures, such as alkali degreasing, hydrochloric acid pickling, water washing, solvent coating, drying, etc., and the original plate needs to be annealed in cover furnace before entering the galvanizing line.

Black iron wire application in the process, the main is through the hot metal billet rolling into six point five mm wire rod, and then put it in the drawing into a line of different diameter, the plant and then gradually narrow drawing plate aperture, cooling and annealing, plating process, such as making a variety of different specifications of the wire, the wire compared with ordinary black iron wire, will be more softer, Softness is also very uniform, color is also consistent, widely used in the construction industry, mining, chemical industry, welding mesh, welding coat hanger, reprocessing industry and so on.

1, stress relief before plating where the maximum tensile strength is greater than 1034Mpa key and important parts before plating should be at 200±10℃ stress relief for more than 1 hours, carburizing or surface quenching parts should be at 140±10℃ stress relief for more than 5 hours.