Progress beyond the state of the art
- The criteria for the best combination of Mn and S contents that can reduce risk for the cracking od semis have been developed and are used in the guidelines to improve hot ductility of steel.
- Iron boride Fe2B has been identified as boron-containing precipitation that has big positive impact on the hot ductility of steel.
- The criteria of controlling iron boride precipitation have been developed and are used in the guidelines to improve hot ductility of steel.
- Recommendations for safe processing in continuous casting of billets, blooms and slabs have been determined based on the in-field tests of the secondary- and of the tertiary cooling conditions including bending -unbending processes.
Expected results until the end of the project
Explanation and description of the combined effects of alloy elements on steel hot ductility:
- The effect of Boron in steels with critical contents of Mn and S
- The effect of Boron in steels in the presence of Nitrogen
- Combined effects of Boron, Titanium and Aluminium
- Combined effects of Carbon, Boron, Titanium and Niobium
Explanation of the effect of temperature and strain on hot ductility during secondary cooling
Explanation of the effect of temperature and strain on hot ductility during tertiary cooling
The guidelines will be proposed to improve the hot ductility of steel and to minimize the risk of semi cracking, by:
- optimization of steel chemistry for billets, blooms and slabs
- optimization of continuous casting practices
Potential impacts
The project will give a better understanding of the complex interactions between micro-alloying elements, precipitates and microstructure which strongly affects the hot ductility of steels in the relationship to continuous casting process parameters, compositions and steelmaking, and downstream processes such as bar and plate rolling. The acquisition of the knowledge will increase the quality of micro-alloy steel billets, blooms and slabs for the European steel industry.