Mn-Mo-Nb-B低碳微合金钢的应变诱导析出

采用热模拟及透射电子显微镜结合纳米束能谱技术,研究了Mn-Mo-Nb-B系多元微合金钢奥氏体变形后等温过程中(松弛)的析出行为。实验结果表明:经变形后,在850℃和900℃保温过程中,Mn-Mo-Nb-B多元微合金钢析出颗粒尺寸在各个阶段均小于相同工艺下Nb-Ti钢中析出相的尺寸。统计结果显示,析出颗粒的尺寸均复合正态分布,并且峰位尺寸接近平均尺寸。析出相中Nb/Ti比随着松弛时间而增大。松弛阶段后期,Mo进入(Ti,Nb)(C,N)的晶格当中,其含量随着时间的延长而增加。

Strain-Induced Precipitation in Mn-Mo-Nb-B Low Carbon Microalloyed Steel

Thermo-simulation test,transmission electron microscopy(TEM)and nanobeam EDS technique were used to investigate the strain induced precipitation behavior during relaxation process after deformed austenite in Mn-Mo-Nb-B low carbon multi-microalloyed steel.The experiment results indicate that during isothermal holding at 850℃ and 900℃ after predeformation,the size of precipitates occurred in the Mn-Mo-Nb-B steel at the different stage are smaller than that happened in the only Nb and Ti-bearing microalloyed steel.The results of statistics show that the distribution of particle size corresponds to the normal one with the peak size approaching to the mean value.The ratio of Nb/Ti of precipitates increased with the relaxing time.After longer holding,Mo atoms would enter the lattice of(Nb,Ti)(C,N)precipitates and its concentration in the precipitates increased with the relaxation time prolonged.