On Control of Grain Coarsening of Austenite by Nano-Scale Precipitate Engineering of TiN-NbC Composite in Ti-Nb Microalloyed Steel

Author(s):  
S.V. Subramanian ◽  
Ma Xiaoping ◽  
Kashif Rehman ◽  
Hatem Zurob
2015 ◽  
Vol 87 (2) ◽  
pp. 219-225 ◽  
Author(s):  
Hao Yang ◽  
Zhenyu Liu ◽  
Xiaoguang Zhou ◽  
Guodong Wang

2011 ◽  
Vol 213 ◽  
pp. 600-603
Author(s):  
Daavood Mirahmadi Khaki ◽  
Vahid Alizaadeh Otaaghvar ◽  
Masoud Mirahmadi Khaki

Thermomechnical processing and controlled rolling of microalloyed steel sheets are affected by several factors according to the final properties of product. To create the high mechanical properties, a uniform and fine-grain structure is necessary in hot rolled final products. To produce such microstructures, every stage of the thermomechanical processing of the steel rolling has to be carefully controlled. Hence, first step is grain coarsening control that it usually occurs during reheating for slab. For this purpose, seven different reheating temperatures between 1000 to 1300 °C with 50 °C increments were chosen in this investigation for soaking treatment. By soaking the specimens in furnace, the grain coarsening temperature (Tgc) is obtained about 1250 °C. Moreover, it is observed that increasing the reheating temperatures causes more decreasing of the precipitates percentage. Hence, for these kinds of steels, the reheating temperature 1200 to 1250 °C is recommended.


2011 ◽  
Author(s):  
Daavood Mirahmadi Khaki ◽  
Amir Abedi ◽  
Francisco Chinesta ◽  
Yvan Chastel ◽  
Mohamed El Mansori

2011 ◽  
Vol 228-229 ◽  
pp. 72-76
Author(s):  
J. H. Yang ◽  
Q. Y. Liu

Deformation dilatometry has been used to simulate controlled hot rolling followed by controlled cooling of a Nb microalloyed pipeline steels, the microstructure and transformation characteristics in the steel and the effect of deformation on transformation are studied. According to the results of both dilatometry measurements and microstructure observations, the continuous cooling transformation curves (CCT) of the tested steels are constructed. The results show that Nb content and deformation enhance the formation of acicular ferrite; the microstructure of the steel range from PF, QF to AF with increasing of cooling rates from 0.5 to 50°C /s in a two stages controlled rolling and the microstructure revolution is sensitive to cooling rates when it is lower than 5°C /s, however, when the cooling rate increasing further, the microstructure didn’t change very much but M/A constituents in matrix is refined and dispersed.


Sign in / Sign up

Export Citation Format

Share Document