铁素体基Ti—Mo微合金钢二相粒子的定量研究

运用物化相分析对Ti0．07-Mo0．2和Ti0．09-Mo0．2的两种Ti—Mo微合金钢析出相中二相粒子的尺寸、分布频度、质量百分数等进行了定量研究，运用Gleebe-3800热模拟机对Ti0．07～Mo0．2和Ti0．09～Mo0．2和Ti0．058的三种钢进行了应力弛豫试验，研究了二相粒子析出前的孕育时间。结果表明，Ti0．07-Mo0．2和Ti0．09-Mo0．2试验钢中，二相粒子尺寸在36nm以下的质量百分数占绝大。随着Ti含量由0．07％增加到0．09％，尺寸36nm以下的二相粒子的质量百分数增加，二相粒子平均尺寸减小。形核率增大，使得形核孕育时间缩短。Ti0．07-Mo0．2钢和Ti0．058钢相比，由于Mo能够降低了Ti，C，N这些形成元素的活度，推迟其碳氮化物在奥氏体形核，降低了形核率，使得Ti0．058钢的析出时间比Ti0．07-Mo0．2钢缩短。

Quantitative Research on the Phase Particles of Ferrite Matrix Ti--Mo Micro--alloyed Steel

Second phase particle size, distribution frequency, mass percentage of Ti0.07--Mo0. 2 and Ti0.09--Mo0. 2 Ti --Mo microalloyed steels were quantitative analyzed by physical and chemical Analysis. Stress relaxation test were researched on Ti0. 07--Mo0. 2, Ti0. 09--Mo0. 2 and Ti0. 058 by Gleeble 3800 thermal simulation machine. The result reply that the particles mass percentage of particles less than 36nm is vast. Mass percentage of particles size less than 36nm increase, average particle size decreases, nucleation rate increase and nucleation incubation time decrease with the Tantinum content increased from 0.07% to 0. 09%. Mo can reduce the activity coefficient of element Ti, C and N, postpone nucleation carbonitride in austenite, reduce the nucleation rate, therefore the precipitation time of Ti0. 58 steel is shorter than Ti0. 07--Mo0. 2 stell.