More than 90% of the corrugated road guardrail is processed by hot-dip galvanizing process, which is anticorrosive and scratchproof. The zinc layer is thick, and the reaction time is long and the anticorrosion and rust prevention effect is good.
There are mainly 6 kinds process method of hot dip galvanizing:
1.Huilin thermal process
Huilin thermal method includes alkali degreasing, hydrochloric acid pickling, water washing, solvent coating, drying and other processing processes, before galvanizing, need to carry out cover furnace annealing. The production process of this method is complicated, the production cost is high, and the corrosion resistance of the coating is affected, so this method has not been developed.
Senjimil method combined annealing process and hot dip galvanizing process, high yield, good quality of galvanizing, this method has been widely used
Meisen process uses alkaline electrolytic degreasing tank to replace degreasing function of oxidation furnace, and other processes are basically the same as Senjimil process. This method is beneficial to furnace safety and reduce production cost, but affects the life of the furnace, so this method is not widely used.
Silas method is the strip after alkaline degreasing, hydrochloric acid to remove oxide skin on the surface of the steel strip, after washing, drying stove is retreated inside put a vertical line in incomplete burning flame, which result in reducing atmosphere in the furnace, to strip rapid heating recrystallization temperature, then cooling strip steel under low hydrogen atmosphere, the immersion liquid zinc galvanizing. But the production process is complex, this method is seldom used.
In the Sharon process, hydrogen chloride gas is sprayed into the strip in the annealing furnace to reach the recrystallization temperature. However, this method is rarely used because chlorinated hydrogen can severely corrode equipment, resulting in high equipment maintenance and replacement costs.
Improved Senjimi is a small cross-sectional corridor connecting the separate oxidation and reduction furnaces in Senjimil method, and forming an organic whole with the preheating furnace, reduction furnace and the whole annealing furnace. Improved Senjimi method has the advantages of high quality, high yield, low consumption and safety.
Post time: Apr-12-2022