Automatic hot galvanizing technique for steel fastener

Abstract

The invention discloses an automatic pot galvanizing technique of a steel fastener which orderly includes the working procedures like caustic washing, acid washing, water washing, assistant plating, drying, crating, galvanizing, centrifugal zinc throwing, water cooling, passivating, drying, packaging, and the like. The galvanizing temperature is between 450 and 480 DEG C; the working procedures of galvanizing and centrifugal zinc throwing are automatically controlled; the centrifugal zinc throwing is to hoist a galvanized workpiece out of a galvanized surface with a galvanizing material basket and lead the galvanized workpiece to horizontally rotate with the galvanizing material basket to make centrifugal movement. The technique leads the galvanized workpiece to instantly carry out zinc throwing without pouring the basket; the temperature drop of the workpiece is small; the galvanizing temperature can be reduced below 480 DEG C; energy is saved; the coherence for the intensity, the precision and the quality of the fastener is ensured; the service life of a zinc boiler is prolonged; the production cost is reduced; the processes for galvanizing and zinc throwing are automatic, safe and effective; besides, the working intensity is low. The technique provided by the invention can be used for carrying out pot galvanizing on the steel fasteners like bolts, nuts, nails, and the like.

Description

technical field [0001] The invention relates to a metal component surface treatment process, in particular to an automatic hot-dip galvanizing process for steel fasteners. Background technique [0002] The hot-dip galvanizing technology is widely used in the surface anticorrosion of steel components. The bonding force between the coating and the bad material is strong, and the coating has a cathodic protection effect on the steel, which can prolong the service life of the components. At present, the hot-dip galvanizing process of bolts, nuts, nails and other steel fasteners includes alkali cleaning→acid cleaning→water washing→plating help→drying→basket loading→galvanizing in the galvanizing pot→lifting the galvanizing pot→workpieces from the galvanizing basket Pour into the centrifuge to dump zinc→water cooling→passivation→drying→packing and other steps. Among them, there are the following disadvantages in the link of galvanizing into the zinc pot→taking out the zinc pot→pou...

AI Technical Summary

Problems solved by technology

[0004] ②The increase of the galvanizing temperature will also cause the strength of the fastener to decrease. In order to ensure the fastening force, the diameter of the fastener needs to be increased

[0005] ③The direction of the nut in the centrifuge is irregular. If the nut hole does not point to the center of the centrifuge when the zinc is thrown out, the residual zinc liquid cannot be thrown out.

In this way, the nut needs to be tapped twice, which destroys the galvanized layer and easily causes accelerated corrosion.

Some manufacturers solve this problem by increasing the fit tolerance of bolts and nuts, but this will have an adverse effect on the tightening force

[0006] ④ Due to the high galvanizing temperature, the corrosion of the zinc liquid on the iron zinc pot is intensified, and a large amount of zinc dross is produced. In order to melt the zinc dross, the temperature needs to be raised again and again, which causes more serious corrosion on the zinc pot.

Such a vicious cycle shortens the life of the zinc pot to only one month, resulting in waste of energy and materials, and a substantial increase in production costs

[0007] In short, in the existing hot-dip galvanizing process of steel fasteners, the process of galvanizing and galvanizing requires manual operation, and the strength and precision of the processed parts cannot be guaranteed. The operation process is labor-intensive, has many safety hazards, and consumes a lot of energy. high operating costs

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