Composite structure coating and spraying method thereof

Abstract

The invention discloses a composite structure coating which is characterized by comprising a stellite alloy layer coated on the surface of a roller body, a MoB / CoCr metal ceramic layer coated on the surface of the stellite alloy layer and a barrier layer arranged on the surface of the MoB / CoCr metal ceramic layer. In the invention, the functional composite structure coating manufactured by the thermal spraying technology and special coating after being subjected to hole sealing can ensure single use time and accumulative service life of a sinking roller and stable roller to be increased by 1-3 times of roller bodies without coatings, so that steel plants improve use efficiency of high value roller bodies, thus improving production efficiency and product quality.

Description

technical field [0001] The invention relates to a composite structural coating and a spraying method thereof. Background technique [0002] Sinking rolls and stabilizing rolls work in the molten zinc or zinc-aluminum liquid in the zinc pot of the hot-dip galvanizing line of the steel plant, and are the core components to ensure the galvanizing quality of the strip steel. The strip steel coming out of the annealing furnace passes through the sinking rolls to realize hot-dip galvanizing process, and obtain effective tension and guidance through the stabilizing roller to ensure that the strip passes through the air knife continuously and stably. Therefore, the surface quality and production efficiency of galvanized sheets depend to a large extent on the surface quality and wear resistance of sinking rolls and stabilizing rolls. [0003] Due to the difference in physical properties between aluminum-zinc alloys and pure zinc, aluminum is an active metal with a melting point of 6...

AI Technical Summary

Problems solved by technology

[0003] Due to the difference in physical properties between aluminum-zinc alloys and pure zinc, metal aluminum is an active metal with a melting point of 660°C and a melting point of zinc at 420°C, which leads to the temperature of molten metal in the zinc pot at 610-620°C (450°C for pure zinc liquid ), therefore the sinking rolls and stabilizing rolls in the high-temperature molten metal solution are easily corroded by molten zinc-aluminum alloys, thereby affecting the quality of the strip

[0004] At present, the base material of the sinking roll and stabilizing roll in the domestic 55% Al-Zn line is 316L or equivalent material, but because there is no coating protection, the roll body is easily corroded by molten zinc-aluminum liquid and adheres to zinc-aluminum slag. As a result, defects are formed on the surface of the strip steel; in addition, after the roll body is used for a cycle, due to the serious damage of the roll body, the roll body must be turned and ground before it can be used again

This way of use not only affects the production efficiency of the steel plant, but also shortens the actual service life of the roller body due to frequent machining