Preparation technique of continuous casting crystallizer copper plate surface cermet coating

Abstract

The invention discloses a preparation technique of a continuous casting crystallizer copper plate surface cermet coating, which comprises the following steps: copper plate surface oil removal, copper plate surface sandblasting, transition layer preparation, coating preparation and heat treatment. The detection indicates that the microhardness of the cermet coating is 1532-1746HV, and the internal stress is 127-136 MPa, so the wear resistance and thermal crack resistance are good; the bonding strength of the coating is 176-189 MPa, so the bonding property is good; the thermal conductivity is 15.2-16.5W / (m.k); and the cermet coating can lower the thermal crack of the crystallizer copper plate in the high-temperature region, can effectively decelerate the heat conduction inside crystallizer (especially the meniscus surface), and can be widely used in continuous casting of a high-speed continuous caster.

Description

technical field [0001] The invention belongs to the technical field of surface treatment, in particular to a preparation process of a cermet coating on the surface of a copper plate of a continuous casting crystallizer. Background technique [0002] In continuous casting production, crystalline copper plate is an important heat transfer component for continuous casting from molten steel solidified into a solid billet shell, and its quality directly affects the quality of the billet surface and the operating rate of the continuous casting machine. With the development of large-scale continuous casting equipment, high casting speed, on-line width adjustment, flow control, breakout prediction and other technologies, the thermal load of the mold copper plate has greatly increased, and the mold copper plate is subject to edge wear and wide surface high temperature during use. Problems such as thermal cracks at the slag line in the area, narrow surface shrinkage, high-temperature ...

AI Technical Summary

Problems solved by technology

The surface roughness of this technical solution after sandblasting is 5~10um. Sandblasting is beneficial to obtain a highly active surface, but excessive sandblasting will make sand fragments easy to be embedded in the copper plate, and the surface activity of the copper plate after sandblasting is too high. It is extremely easy to oxidize and should be sprayed as soon as possible without preheating; in addition, the cermet coating prepared by supersonic flame spraying is porous, and some voids even extend from the surface of the coating to the surface of the protected substrate. Accumulation at the interface will cause cracking and peeling off of the coating