Preparation method for protective coating of zinc pan roller sleeves and bushes

Abstract

The invention discloses a preparation method for a protective coating of zinc pan roller sleeves and bushes. The method comprise: cleaning and preheating surfaces of a roller sleeve and a bush, employing plasma built-up welding equipment to performing multi-layer powder built-up welding, selecting single cobalt-base alloy with relatively low hardness as a built-up welding combination bottom layer, and employing a cobalt-base alloy powder and a boron nitride powder as other layers of built-up welding powder materials, arranging two powder feeders respectively for putting the cobalt-base alloy powder and the boron nitride powder on the plasma built-up welding equipment, and respectively setting powder sending parameters, so as to realize independent sending of the two powders; and setting corresponding built-up welding parameters, keeping warm of the interior of a furnace after built-up welding and slowly cooling along with the furnace, and performing machining the built-up welded layer to obtain the protective coating with the thickness of 2.0-15 mm. By using the protective coating prepared by the method and used for the roller sleeve and the bush, the service life of the roller sleeve and the bush is effectively improved, the wear resistance and the lubrication performance are improved, strip steel is guaranteed to smoothly enter or get out of a zinc liquid system of a zinc pan, and the production efficiency of hot galvanized plates and strips is improved.

Description

technical field [0001] The invention relates to a method for preparing zinc pot roll bushings and protective coatings for bushings. Background technique [0002] In the metallurgical industry, zinc pots are used for hot-dip galvanizing treatment of hot-dip galvanized strips. Hot-dip galvanized strips are mostly used in automobiles, construction and household appliances industries, especially the casings of various cars or household appliances. [0003] Because it is a large-scale industrial production, in the large-scale continuous production process, most of the cold-rolled metal strips used as the base material of hot-dip galvanized sheets reach 40 tons of coils before unrolling, and the cold-rolled metal strips are pickled and continuously Annealing, zinc pot hot-dip galvanizing and other production treatments and chemical treatments are re-coiled. [0004] Usually, the zinc pot roll shaft is composed of a sinking roll and two stabilizing rolls. The sinking roll is a pas...

AI Technical Summary

Problems solved by technology

Under the simultaneous action of corrosion, wear, high temperature and high mechanical force in the liquid zinc pot, it is very easy to cause damage to the transmission parts of the zinc pot roller. Normal operation of zinc pot rolls

[0005] Based on the chemical properties of cobalt-based alloys, which are difficult to dissolve in zinc liquid, it is used as a material for making shaft sleeves and bushings, but its physical properties, especially poor lubricating properties, cannot meet the needs of use. In order to increase shaft sleeves and bushings The lubricating performance of the bushing system is to add about 0.15-0.2wt% lead to the zinc pot to meet the requirements of the lubricating performance of the bushing and bushing, but it is easy to cause environmental pollution, so this method has been greatly reduced

With the sharp increase in production in modern enterprises, the strip speed reaches 200m / min, and the tension reaches 10 tons, which greatly reduces the service life of the original bushing and bushing

Chinese patent CN 101596634A discloses the use of artificial electrode arc welding to surfacing cobalt-based alloys on stainless steel substrates to make shaft sleeves and bushings. This method cannot achieve arbitrary addition of effective ceramic components, and it is difficult to achieve integral shaft sleeves and bushing inner holes.

In the Japanese patent JP03094984A, plasma surfacing welding can realize the proportional addition of corrosion-resistant ceramic materials and the overall surfacing welding of the inner hole of the bushing, but the surfacing material does not significantly improve the lubrication performance between the friction pairs, and the structure of the surfacing layer is comparatively poor. Single, resulting in defects in work performance

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