|
|
|
| Precipitation behavior of TiN in Nb-Ti alloyed steel during continuous casting process |
| QU Tian-peng，WANG De-yong，XU Zhou，CHEN Kai-lai，TIAN Jun |
| （Shagang School of Iron and Steel，Soochow University，Suzhou 215021，Jiangsu，China） |
|
|
|
|
Abstract Transverse crack on the slab corner became server defect for Nb-containing steel due to precipitation of NbN particles along the prior austenite grain boundary. By adding strong nitride element Ti the precipitation of NbN can be inhibited instead by TiN particle that keep the Nb as solution condition in steel. In the present research the formation mechanism of TiN was studied by thermodynamics calculation and experiments in lab. It came to the conclusions as follow. With the increase of cooling rate of molten steel，the precipitation location of TiN particles transfers from γ grains boundary into grain inner. Basing on the Ohnaka micro-segregation model，the precipitation behavior of [Ti]，[N] and [Ti][N] were investigated under various solid fraction during solidification process. As the solid fraction is larger than 0.95，the [Ti][N] value was higher than the one under equilibrium state and TiN particles precipitated from solidifying front. Furthermore，the high melting element such as non-metal inclusion Al2O3 plays an important role for decreasing nucleation potential barrier of TiN，which enhanced formation of TiN particles in molten steel. For micro-segregation model，according to segregation degree at solidification front，they can be sorted as following sequence，Scheil model＞Ohnaka model＞B-F model＞C-K model＞V-B model＞Level model.
|
|
Received: 14 February 2017
Published: 12 May 2017
|
|
|
|
| [1] |
Ji-yuan Luo, Xin-ming Ren, Xiao-chuan Chong, Dong-hai Ding, Bei-yue Ma, Guo-qing Xiao, Jing-kun Yu. Recent progress in synthesis of composite powders and their applications in low-carbon refractories[J]. JOURNAL OF IRON AND STEEL RESEARCH,INTERNATIONAL, 2022, 29(7): 1041-1051. |
| [2] |
Chao Yu, Bo Dong, Yu-feng Chen, Bei-yue Ma, Jun Ding, Cheng-ji Deng, Hong-xi Zhu, Jing-hui Di. Enhanced oxidation resistance of low-carbon MgO–C refractories with ternary carbides: a review[J]. JOURNAL OF IRON AND STEEL RESEARCH,INTERNATIONAL, 2022, 29(7): 1052-1062. |
| [3] |
Qian Sun, En-hui Wang, Xin-mei Hou, Zhi-jun He, Tong-xiang Liang. Effect and mechanism of nano-Ca10(PO4)6(OH)2 additive on compressive strength of calcium aluminate cement at high temperature[J]. JOURNAL OF IRON AND STEEL RESEARCH,INTERNATIONAL, 2022, 29(7): 1063-1072. |
| [4] |
Rui-qiang Bai, Si-yang Liu, Fei-xiong Mao, Yuan-yuan Zhang, Xin Yang, Zhi-jun He. Wetting and corrosion behavior between magnesia–carbon refractory and converter slags with different MgO contents[J]. JOURNAL OF IRON AND STEEL RESEARCH,INTERNATIONAL, 2022, 29(7): 1073-1079. |
| [5] |
Bei-yue Ma, Xin-ming Ren, Zhi Gao, Fan Qian, Zhao-yang Liu, Guo-qi Liu, Jing-kun Yu, Gao-feng Fu. Influence of pre-synthesized Al2O3–SiC composite powder from clay on properties of low-carbon MgO–C refractories[J]. JOURNAL OF IRON AND STEEL RESEARCH,INTERNATIONAL, 2022, 29(7): 1080-1088. |
| [6] |
Mao-qi Ju, Man-fei Cai, Yong-he Liang, Jian-hua Nie, Meng-zhen Guo. Application of calcium alumino-titanate to taphole clay[J]. JOURNAL OF IRON AND STEEL RESEARCH,INTERNATIONAL, 2022, 29(7): 1089-1100. |
|
|
|
|
2017, Vol. 36 
