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.

Hot wire plating adopts zinc-free slag to add hot molten zinc and galvanizing, which avoids the traditional heating process, radiates 1653 hot molten zinc on surface 4102 of zinc liquid surface, and reduces the high temperature oxidation of zinc liquid surface. At the same time, the heating body is in contact with the zinc liquid, and the heat is directly transferred to the zinc liquid. The utilization rate of heat energy can reach more than 90%, and the heat radiation on the zinc liquid surface is reduced.

Want to keep a dog friends need to know: choose suitable dog and family environment of the cage, the dog cage to consider the material, the size of the dog, space, location, whether easy to clean and so on. Let’s take a look at these aspects.

There is a connection between the hook mesh and the aperture, in short, the general hole small hook mesh, the wire is also very small; Aperture is large, hook mesh wire is generally larger. The weaving of the hook mesh also has certain rules, using the first pre-bent into a wavy wire, and then woven into the hook mesh. According to the knitting method, the hook mesh can be divided into: closed weaving, two-way plain weaving, one-way corrugated weaving, two-way plane weaving, two-way corrugated weaving, rectangular hole weaving.