【摘要】 综合运用透射电镜法、金相观察和线膨胀系数(α)-温度(T)曲线法,研究了26Cr2Ni4MoV钢马氏体在加热过程中发生的转变,及其与组织遗传的关系.通过对α-T曲线的研究,从理论上推导并建立了半定量分析组织转变的参数体系;证明了α-T曲线中异常线膨胀系数与相变速率、异常线膨胀量与相变量之间的正比关系;并分析了该钢的异常膨胀行为.进一步证实:该钢的组织遗传与其在加热过程中板条界残余奥氏体的不易分解有关.更多还原

【Abstract】 Metallography, TEM observation and α-T curves (thermal expansion coefficient-temperature curves ) are used to investigate the heating transformation dynamics and its relationship with grain heredity of martensite in 26Cr2Ni4MoV steel. A system of analysing parameters was established with theretical derivation to calculate transformation dynamics; which proves that abnormal thermal expansion coefficient αa is proportional to transformation velocity df/dt, so is the relation of abnormal thermal expansion rate △l2/l and transformation percentage. By means of the α-T curve analysis, the abnormal thermal expansion behavior at 560℃-630℃ is studied and attributed to the decomposition of retained austenite. All results from TEM analysis, metallography and α-T curve analysis appear consistant to one another quite well, which confirms that the grain heredity of 26Cr2Ni4MoV steel is caused by undecomposed interlath retained austenite.更多还原