Hardness is one of the most commonly used indexes in mechanical properties of metal materials. A fast and economical test method for hardness test is introduced in wire factory. But for the hardness of metal materials, there is not a unified and clear definition including all test methods at home and abroad. Generally speaking, the hardness of a metal is often thought of as the resistance of a material to plastic deformation, scratches, wear, or cutting.
In the adjustment of the dipping distance of the large galvanized wire, keep the original speed unchanged, and determine the dipping time (1) according to T = KD, where: T is the constant of the dipping time, take 4-7d is the diameter of the steel wire mm, and then estimate the dipping distance. By adjusting the zinc dipping distance, the zinc dipping time of steel wire of various specifications is shortened by 5s on average than that before adjustment. In this way, the zinc consumption is reduced, and the zinc consumption per ton of steel wire is reduced from 61kg to 59.4kg.
Hot dip galvanizing is in the heating of molten zinc dip plating, production speed, coating thick but uneven, the thickness of the market allows 45 microns, up to 300 microns or more. The color is dark, the consumption of zinc metal, and the matrix metal to form an infiltration layer, corrosion resistance is good, hot galvanized outdoor environment can be maintained for decades. There are two principles for the protection of zinc coating on iron matrix: on the one hand, although zinc is more active and easy to oxidize than iron, its oxide film is not as loose as iron oxide and is relatively dense. The formation of a dense oxide layer on the surface inhibits further oxidation of zinc inside.
Especially after passivation of galvanized layer, the surface oxide layer is more dense, itself has a high oxidation resistance. On the other hand, when the surface layer of zinc coating is damaged, exposing the inner iron matrix, because zinc is more active than iron, zinc will bear the role of sacrificial zinc anode, zinc will oxidize before iron, thus protecting the iron layer from damage.
Post time: 16-08-21