Effect of Nb(C,N) dissolution on growth behavior of high Nb austenite grains
YU Jianguo1,QIAO Guiying2
（1. Department of Mechanical Engineering, Chengde Petroleum College, Chengde 067000, Hebei, China;
2. Key Laboratory of Applied Chemistry of Hebei Province, School of Environment and
Chemical Engineering, Yanshan University, Qinhuangdao 066004, Hebei, China）
Abstract： In order to investigate the effect of Nb content of highNb steels on the growth of austenite grain growth during heating process. Means of chemical dissolution, filtration and separation and inductively coupled plasma spectrum were taken to examine the content of dissolved Nb in two highNblowTi microallying steels at different temperatures. And a comparative study of the austenite grain growth behavior was carried out. Results showed that the mass fraction of dissolved Nb in lowNb steel was higher than that in the highNb steel at lower heating temperatures. With heating temperature increasing, the content of dissolved Nb in highNb steel quickly increased. However, even if heating temperature gets to 1 300 ℃, the Nb can not be completely dissolved. A small amount of Nb existed in (Ti,Nb)(N,C) precipitate. The temperature of the austenite grain quick growth was related to the temperature at which the content of dissolved Nb quickly increased. As the mass fraction of Nb in steels increased from 0.082% to 0.120%, the critical temperature of the austenite grain quick growth arised from 1 050 to 1 150 ℃. For the highNb steels, the austenite grain size was smaller than 100 μm when heating temperature was in the range from 1 150 to 1 250 ℃.
于建国, 乔桂英. Nb(C,N)溶解对高铌奥氏体晶粒长大行为的影响[J]. 中国冶金, 2019, 29(5): 48-52.
YU Jianguo,QIAO Guiying. Effect of Nb(C,N) dissolution on growth behavior of high Nb austenite grains[J]. China Metallurgy, 2019, 29(5): 48-52.
2019, Vol. 29 
