In recent years, focus on "reduce costs, protect the production," the center, Baosteel Branch research and development efforts to improve the life of spare parts cost reduction as the goal to promote the maintenance of surface treatment technology, and achieved good results in forging rings.
A laser surface modification technology
Laser surface modification since the 1980s is the rapid development of new technologies, carbon steel, alloy steel by laser surface modification treatment, the anti-wear and anti-corrosion properties of high-temperature oxidation are greatly improved. In recent years, laser surface modification technology in petroleum, chemical, power and other sectors of the rotor on the type of equipment to get a better application maintenance, combined with Baosteel Branch equipment maintenance, repair, the demand for laser surface hardening, laser cladding technology a useful attempt, and achieved good results.
Baosteel hot rolling mill 1580 drum unit flat head flat shears abnormal wear, unilateral wear volume of 1.5mm, flat head and rotating drum fork head gap tolerance, causing abnormal vibration transmission. Drum material SF590, manufacture high precision, using surfacing repair risks, therefore, try to use laser cladding method of repair. The first head surface of the drum flat cladding 2mm thick nickel base alloy, and then machined, back to the original drawings. As the drum flat head hardening characteristics of a good selection of nickel-base alloys by laser cladding repair, the surface material has been strengthened, greatly improved wear resistance, impact resistance, after four years of production use, size remained unchanged, to obtain good results.
Two thermal spray technology
Thermal spraying the coating material is melted into a heat source and a high-speed flow of the molten or semi-molten state to the substrate surface of the microparticle spraying performance and functional coating of a certain technology. Using thermal spray processes, the parts of the surface can be obtained wear and corrosion resistance, heat resistance, oxidation resistance, thermal insulation, and other physical and chemical properties. With chromium plating due to mist generated in the process, water pollution of the environment containing hexavalent chromium ions, compared cleaner thermal spraying process, in line with environmental policy Steel clean production, and thermal sprayed wear resistant coating, corrosion resistance higher and more stable, costs are roughly equal. According to the characteristics of thermal spray process, Baosteel Branch targeted, selective thermal spray process carried out to replace chromium plating for spares repair work.
Baosteel Branch slab caster mold short side of the original use of nickel-plated copper, copper-base metal switch with a high bonding strength self-fluxing spraying, coating temperature hardness, wear resistance is greatly improved, life of the furnace from 350 to 2,000 around the furnace.
Three new materials
Hard composite plate technology in recent years with the formation of a new wear-resistant material, which consists of two layers of the surface layer and the substrate material of different nature: the surface layer of high hardness carbide substrate is a carbon steel or high-quality carbon structural steel. This particular composite steel structure, determines its characteristics: the surface layer has high hardness, excellent wear resistance, substrate has good weldability.
Baosteel Branch bof secondary dedusting fan, ironworks blast furnace dust blower, sintering boiler circulating fan impeller made of composite steel, compared to the surfacing alloy, life increased 3 times, and achieved good results. By application practice, Baosteel mastered the basic essentials composite plate application technology: such selection should be based on conditions decided to use iron-based alloy or nickel-based alloy composite plate, is the choice of normal or high temperature alloy composite steel alloy; composite steel cutting, Flame cutting should not be used, and should be cut using a plasma; addition, attention should composite plate having directivity characteristics, different direction, and its wear resistance vary greatly.
The next few years, Baosteel Branch from the following aspects to promote the further development of this work:
- Trace thermal spraying of new technologies, promote equipment, technology upgrades optimization to accelerate the application of the coating material research, establish systematic, relatively complete application technology standards;
- promote the application of wear-resistant steel sheet, expanded plate in wear resistant composite fan application, promote resistant composite plate in the other devices on the application, the system acquire the relevant application technology;
- continue to explore the research of laser surface modification technology in the spare parts repair applications, to further improve the shaft and the roller-type parts of life;
- Tracking and digestion of foreign advanced experience, according to the actual Baosteel Branch, targeted to carry out backup roll mill Surfacing Technology.