30Cr1Mo1V高中压转子材料晶核形成及长大行为研究
发布时间：2018-10-16 13:33
【摘要】：本文将高中压转子材料30Cr1Mo1V加热至不同的温度区间,对30Cr1Mo1V在加热过程中的组织遗传现象及晶粒长大行为进行了研究。通过与30Cr2Ni4MoV对比,观察分析了两种转子材料粗大非平衡组织重新加热至Ac1~Ac3之间及Ac3以上的晶核形成及长大行为;对30Cr1Mo1V高中压转子材料在重新加热至Ac3以上时奥氏体晶粒的变化进行了分析,建立了该材料在高温区间的奥氏体晶粒长大模型。同时,为了获得细化晶粒以及改善混晶程度的工艺参数,本文将(过)深冷处理工艺应用到30Cr1Mo1V的加热工艺中,研究了(过)深冷处理工艺对该转子材料粗大非平衡组织重新加热过程中奥氏体晶核形成及长大行为的影响。本文的研究在实际应用中具有一定的理论价值,具体结果如下:1.30Cr1Mo1V和30Cr2Ni4MoV中合金元素的添加会影响α相再结晶程度,从而影响奥氏体晶核形成机制及其长大的取向。30Cr1Mo1V高中压转子材料主要以球状机制形核,30Cr2Ni4MoV低压转子材料由于Ni元素含量较高,推迟α相再结晶的程度较大,奥氏体开始形核温度较高,同时导致其高温淬火时产生的残余奥氏体含量较30Cr1Mo1V高中压转子材料多。而针状奥氏体主要依附残余奥氏体形核,30Cr2Ni4MoV低压转子材料非平衡组织重新加热奥氏体化过程中针状奥氏体优先在α相板条束之间形核。2.非平衡组织重新加热奥氏体化过程中,不仅针状奥氏体晶核的形成与长大会产生组织遗传,球状奥氏体晶核的形成与长大也会对组织遗传产生影响。两种转子材料中合金元素含量不同,球状奥氏体对组织遗传的影响程度也不相同,即Ni元素含量越高,球状奥氏体越易产生组织遗传。3.30Cr1Mo1V高中压转子钢粗大非平衡组织在重新加热至稍高于Ac3以上温度时,晶粒尺寸变化不大,晶粒呈现一定的取向。当保温时间为定量,升温至1000℃以上时,奥氏体晶粒尺寸不断增大:奥氏体晶粒在加热至1100℃以下时变化速率较小;但当温度上升至1100℃至1125℃之间时,其增长迅速;温度继续上升,晶粒大小趋于稳定。当加热温度保持恒定时,奥氏体晶粒先急剧变大;增加保温时间,晶粒增长速率逐渐减缓至趋于平稳;加热至1100℃以上保温20h时,其尺寸仍在继续增大。通过上述分析,建立了30Cr1Mo1V粗大非平衡组织重新加热时高温区间的Beck模型以及等温条件与非等温条件下的晶粒长大模型4.在非平衡组织重新加热奥氏体化过程中,由于过(深)冷处理增加了超细微碳化物的析出,促进了α→γ相转变,从而导致奥氏体晶核在较低温度形成,并在两相区Ac1~Ac3之间完全奥氏体化。重新在1000℃以下加热奥氏体化时,过(深)冷处理在细化奥氏体晶粒的同时还使其混晶度降低;1000℃以上加热奥氏体化时,随温度的升高,晶粒粗化的同时其混晶度也随之增加。
[Abstract]:In this paper, the microstructure genetic phenomenon and grain growth behavior of 30Cr1Mo1V during heating were studied by heating the high pressure rotor material 30Cr1Mo1V to different temperature ranges. By comparing with 30Cr2Ni4MoV, the nucleation and growth behavior of two kinds of rotor materials with coarse non-equilibrium microstructure reheated to Ac1~Ac3 and above Ac3 were observed and analyzed. The austenite grain growth model of 30Cr1Mo1V high pressure rotor material during reheating above Ac3 was analyzed and the austenite grain growth model was established in the high temperature range. At the same time, in order to obtain the process parameters to refine the grain and improve the degree of mixing, the (supercooled) cryogenic treatment process is applied to the heating process of 30Cr1Mo1V. The effect of cryogenic treatment on the nucleation and growth behavior of austenite during the reheating of the coarse non-equilibrium structure of the rotor material was studied. The results are as follows: the addition of alloying elements in 1.30Cr1Mo1V and 30Cr2Ni4MoV will affect the recrystallization degree of 伪 phase. Thus, the nucleation mechanism of austenite and the orientation of austenitic growth are affected. The high pressure 30Cr1Mo1V rotors mainly nucleate by spherical mechanism, and the low pressure 30Cr2Ni4MoV rotor materials delay the recrystallization of 伪 phase because of the high content of Ni elements. The austenite nucleation temperature is higher and the content of residual austenite during high temperature quenching is higher than that of 30Cr1Mo1V high pressure rotor material. Acicular austenite mainly depends on residual austenite nucleation, and acicular austenite preferentially nucleates between 伪 -phase lath bundles during reheating austenitization of 30Cr2Ni4MoV low pressure rotor materials. 2. In the process of reheating austenitization of non-equilibrium structure, not only the formation and growth of acicular austenitic crystal nucleus will produce microstructure heredity, but the formation and growth of spherical austenitic crystal nucleus will also influence the structure heredity. The content of alloying elements in the two rotors is different, and the influence of spherical austenite on the structure heredity is also different, that is, the higher the content of Ni element, The larger non-equilibrium microstructure of 3.30Cr1Mo1V high pressure rotor steel is reheated to a slightly higher temperature than Ac3, the grain size changes little and the grain shows a certain orientation. When the holding time is quantitative, the austenite grain size increases when heating temperature is above 1000 鈩，
本文编号：2274522
[Abstract]:In this paper, the microstructure genetic phenomenon and grain growth behavior of 30Cr1Mo1V during heating were studied by heating the high pressure rotor material 30Cr1Mo1V to different temperature ranges. By comparing with 30Cr2Ni4MoV, the nucleation and growth behavior of two kinds of rotor materials with coarse non-equilibrium microstructure reheated to Ac1~Ac3 and above Ac3 were observed and analyzed. The austenite grain growth model of 30Cr1Mo1V high pressure rotor material during reheating above Ac3 was analyzed and the austenite grain growth model was established in the high temperature range. At the same time, in order to obtain the process parameters to refine the grain and improve the degree of mixing, the (supercooled) cryogenic treatment process is applied to the heating process of 30Cr1Mo1V. The effect of cryogenic treatment on the nucleation and growth behavior of austenite during the reheating of the coarse non-equilibrium structure of the rotor material was studied. The results are as follows: the addition of alloying elements in 1.30Cr1Mo1V and 30Cr2Ni4MoV will affect the recrystallization degree of 伪 phase. Thus, the nucleation mechanism of austenite and the orientation of austenitic growth are affected. The high pressure 30Cr1Mo1V rotors mainly nucleate by spherical mechanism, and the low pressure 30Cr2Ni4MoV rotor materials delay the recrystallization of 伪 phase because of the high content of Ni elements. The austenite nucleation temperature is higher and the content of residual austenite during high temperature quenching is higher than that of 30Cr1Mo1V high pressure rotor material. Acicular austenite mainly depends on residual austenite nucleation, and acicular austenite preferentially nucleates between 伪 -phase lath bundles during reheating austenitization of 30Cr2Ni4MoV low pressure rotor materials. 2. In the process of reheating austenitization of non-equilibrium structure, not only the formation and growth of acicular austenitic crystal nucleus will produce microstructure heredity, but the formation and growth of spherical austenitic crystal nucleus will also influence the structure heredity. The content of alloying elements in the two rotors is different, and the influence of spherical austenite on the structure heredity is also different, that is, the higher the content of Ni element, The larger non-equilibrium microstructure of 3.30Cr1Mo1V high pressure rotor steel is reheated to a slightly higher temperature than Ac3, the grain size changes little and the grain shows a certain orientation. When the holding time is quantitative, the austenite grain size increases when heating temperature is above 1000 鈩，
本文编号：2274522
本文链接：https://www.wllwen.com/kejilunwen/jiagonggongyi/2274522.html
