Laser fusion welding method of abrasion-proof heat-proof composite coating on surface of tuyeres of blast furnace port sleeve

Abstract

The invention relates to a wear-resistant and heat-resistant complex coating laser fusion approach on the tuyere surface of a blast furnace. The high power laser quickly scans and welds the tuyere surface of the blast furnace and metallurgically combines with the substrate materials to form a good nickel-based toughness transition layer. The laser bandwidth clads the nickel-based toughness transition layer to produce a cobalt-based alloy with excellent effects of wear-resistant and heat-resistant. The technology process comprises the following steps: firstly the blast furnace tuyere is pre-treated; secondly the pre-deposited nickel-base alloy is coated with plasma; thirdly the nickel-based alloy is welded quickly by the high power laser; fourthly the cobalt-based alloy is clad by the high power laser bandwidth; finally is the following heat treatment. The invention can avoid the structure stress caused by the difference between the substrate material and the cladding material in the laser cladding process. In addition, the treatment to the copper substrate before and after laser cladding can decrease temperature gradient so as to prevent the cladding layer from cracking to a certain degree.

Description

technical field [0001] The invention belongs to the technical field of laser rapid fusion welding, in particular to a method for preparing the surface of a tuyere cover of a blast furnace and repairing a wear-resistant and heat-resistant coating. Background technique [0002] The blast furnace tuyere sleeve is the "throat" spare part of the ironmaking blast furnace and one of the key equipment to ensure the production of the blast furnace. The length of its life directly affects whether the blast furnace can keep running smoothly, obtain high production and reduce ironmaking costs. The working environment of blast furnace tuyere sleeves is very harsh. Under high temperature, they are directly subjected to the thermal shock of liquid slag iron and the wear of falling hot materials, as well as the erosion of coal powder in the air flow. The sealing sleeves are often damaged due to local corrosion. The damage of the tuyere cover not only increases the shutdown rate of the blast...

AI Technical Summary

Problems solved by technology

Damage to the tuyere cover not only increases the blast furnace shutdown rate and causes great losses, but also brings many difficulties to the operation of the blast furnace

The recognized thermal conductivity of pure copper and its alloys makes it a stable material in the reducing atmosphere of blast furnaces, but the performance of the material can no longer meet the requirements of high temperature strength and wear resistance; at present, the average service life of domestic tuyere sleeves is about 2000 hours, which is It is an effective measure to improve the service life of the tuyere sleeve by surface treatment to improve wear resistance and heat resistance.

[0003] Although the widely used surface treatment methods such as electroplating, thermal spraying and infiltration can improve the wear resistance of blast furnace tuyere sleeves, the strengthening effect of the coatings prepared by electroplating and thermal spraying is mechanically combined with the substrate to a certain extent. ; Diffusion between the metal and the copper lattice of the permeable coating is difficult to control in the application, and the higher cost also limits their application

[0004] At present, the main problems facing the further application of laser cladding technology are: the lack of in-depth research on the formation and behavior of cracks in the laser cladding process; the lack of cladding materials specifically for the characteristics of the laser cladding process; the detection and implementation of the laser cladding process automation control

Among them, the crack problem is particularly serious