Billet Oxidation Problem
Technical solutions for high temperature anti-oxidation of steel billets
Core Technologies
Nano-ceramic Powder Preparation Technology
- Preparation Technology for Low-Sodium Microcrystalline Alumina Powder;
- Control Technology for Crystalline Alumina Powder Formulation;
- Particle Size Composition and Optimization Technology;
- Ultrafine Powder Dry Powder Deagglomeration Technology.
Core Technologies for Generation II Anti-Oxidation Coatings
1.Optimized Environmentally Friendly Component Formula; 2.Enhanced Anti-Oxidation Performance.① Improved Adhesion between Coating and Steel Billet;② Improved High-Temperature Toughness and Thermal Shock Resistance of Coating; ③ Enhanced High-Temperature Density of Coating.
Automated Spraying
Automated spraying machines are designed based on site conditions to achieve automated, efficient, and environmentally friendly steel billet spraying operations.
Technical Principle
- Using a specific crystal form of alumina ceramic nanopowder as the base material, combined with a nanoceramic binder and nanocatalyst, it achieves low-temperature curing. At temperatures above 500°C, the nanoceramic particles connect and the grains fuse, achieving sintering densification.
- The active substances in the coating material fully fill the remaining voids in the ceramic coating at high temperatures, enhancing the coating’s self-healing ability and adhesion.
- Ceramic whiskers are used to achieve inter-grain bonding and enhance the coating’s toughness;
- The coating’s expansion coefficient is adjusted to match the steel billet during heating, and rapidly contracts during cooling, allowing for complete descaling during the descaling process.
Features of Nano Ceramic Coating
1.Significant Results
Reducing oxidation and burning losses on steel billets by 90% with significant results and relatively low material costs, it can create substantial economic benefits for steel companies.
2.Room-temperature Curing and Densification
After application, the film forms and solidifies naturally, eliminating the need for sintering and cracking, allowing direct use in the furnace.
3.Environmentally Friendly
The primary ingredient is nano-alumina, and all auxiliary ingredients are safe and environmentally friendly inorganic raw materials. They are non-corrosive, contain no organic volatiles, and do not affect the steel rolling process.
Basic Properties of Nano Ceramic Coatings
| Items | Test Standards | Performance Parameters | Items | Performance Parameters |
| Status in the Container | GB 9755-2001 5.3 | Uniform, No Agglomeration, Flocculation or Precipitation | Thermal Expansion | The expansion coefficient is similar to that of the metal matrix and is not easy to crack |
| Color | GB/T 1722-1992 | White | Adhesion | Strong bonding with the steel billet, not easy to fall off |
| Adhesion | GB/T 9286-1998 | Level 1 | Healing | Self-healing ability at high temperatures |
| Flexibility | GB/T1731-93 | ≥3mm | Density | Able to maintain density over the entire temperature range |
| Coating Hardness | GB/T 6739-2006 | 8H | Corrosion Resistance | Acid and alkali resistant and corrosion resistant |
| Bond Strength | GB/T 16777-2008 | 8MPa | Volatility | The vapor pressure is low at high temperature, and the volatilization loss of the coating is very small |
| Falling Sand Abrasion Test of Coating Film | GB/T 23988-2009 | 3.0L/um | Temperature Resistance Range | 1300℃ |
| Density | Volumetric Method | 1.9g/cm3 | Persistence | Can maintain good anti-oxidation performance for a long time |
Application effect of high temperature anti-oxidation technology for steel billets
- In the laboratory, after coating, carbon steel, bearing steel, pipeline steel, tool steel, and 304 stainless steel were oxidized at 1200-1300°C for three hours, achieving zero oxidation and zero burnout.
- In industrial applications, this coating can reduce oxidation and burnout by 80-95%.
The use of high-temperature protective coating technology can reduce oxidation and burning losses by more than 90%, greatly improve the steel yield during the production process, directly reduce the difficulty of removing iron oxide scale, alleviate the depletion of surface elements, and improve the output and quality of steel.
