【摘要】：本文將高中壓轉(zhuǎn)子材料30Cr1Mo1V加熱至不同的溫度區(qū)間,對(duì)30Cr1Mo1V在加熱過程中的組織遺傳現(xiàn)象及晶粒長(zhǎng)大行為進(jìn)行了研究。通過與30Cr2Ni4MoV對(duì)比,觀察分析了兩種轉(zhuǎn)子材料粗大非平衡組織重新加熱至Ac1~Ac3之間及Ac3以上的晶核形成及長(zhǎng)大行為;對(duì)30Cr1Mo1V高中壓轉(zhuǎn)子材料在重新加熱至Ac3以上時(shí)奧氏體晶粒的變化進(jìn)行了分析,建立了該材料在高溫區(qū)間的奧氏體晶粒長(zhǎng)大模型。同時(shí),為了獲得細(xì)化晶粒以及改善混晶程度的工藝參數(shù),本文將(過)深冷處理工藝應(yīng)用到30Cr1Mo1V的加熱工藝中,研究了(過)深冷處理工藝對(duì)該轉(zhuǎn)子材料粗大非平衡組織重新加熱過程中奧氏體晶核形成及長(zhǎng)大行為的影響。本文的研究在實(shí)際應(yīng)用中具有一定的理論價(jià)值,具體結(jié)果如下:1.30Cr1Mo1V和30Cr2Ni4MoV中合金元素的添加會(huì)影響α相再結(jié)晶程度,從而影響奧氏體晶核形成機(jī)制及其長(zhǎng)大的取向。30Cr1Mo1V高中壓轉(zhuǎn)子材料主要以球狀機(jī)制形核,30Cr2Ni4MoV低壓轉(zhuǎn)子材料由于Ni元素含量較高,推遲α相再結(jié)晶的程度較大,奧氏體開始形核溫度較高,同時(shí)導(dǎo)致其高溫淬火時(shí)產(chǎn)生的殘余奧氏體含量較30Cr1Mo1V高中壓轉(zhuǎn)子材料多。而針狀?yuàn)W氏體主要依附殘余奧氏體形核,30Cr2Ni4MoV低壓轉(zhuǎn)子材料非平衡組織重新加熱奧氏體化過程中針狀?yuàn)W氏體優(yōu)先在α相板條束之間形核。2.非平衡組織重新加熱奧氏體化過程中,不僅針狀?yuàn)W氏體晶核的形成與長(zhǎng)大會(huì)產(chǎn)生組織遺傳,球狀?yuàn)W氏體晶核的形成與長(zhǎng)大也會(huì)對(duì)組織遺傳產(chǎn)生影響。兩種轉(zhuǎn)子材料中合金元素含量不同,球狀?yuàn)W氏體對(duì)組織遺傳的影響程度也不相同,即Ni元素含量越高,球狀?yuàn)W氏體越易產(chǎn)生組織遺傳。3.30Cr1Mo1V高中壓轉(zhuǎn)子鋼粗大非平衡組織在重新加熱至稍高于Ac3以上溫度時(shí),晶粒尺寸變化不大,晶粒呈現(xiàn)一定的取向。當(dāng)保溫時(shí)間為定量,升溫至1000℃以上時(shí),奧氏體晶粒尺寸不斷增大:奧氏體晶粒在加熱至1100℃以下時(shí)變化速率較小;但當(dāng)溫度上升至1100℃至1125℃之間時(shí),其增長(zhǎng)迅速;溫度繼續(xù)上升,晶粒大小趨于穩(wěn)定。當(dāng)加熱溫度保持恒定時(shí),奧氏體晶粒先急劇變大;增加保溫時(shí)間,晶粒增長(zhǎng)速率逐漸減緩至趨于平穩(wěn);加熱至1100℃以上保溫20h時(shí),其尺寸仍在繼續(xù)增大。通過上述分析,建立了30Cr1Mo1V粗大非平衡組織重新加熱時(shí)高溫區(qū)間的Beck模型以及等溫條件與非等溫條件下的晶粒長(zhǎng)大模型4.在非平衡組織重新加熱奧氏體化過程中,由于過(深)冷處理增加了超細(xì)微碳化物的析出,促進(jìn)了α→γ相轉(zhuǎn)變,從而導(dǎo)致奧氏體晶核在較低溫度形成,并在兩相區(qū)Ac1~Ac3之間完全奧氏體化。重新在1000℃以下加熱奧氏體化時(shí),過(深)冷處理在細(xì)化奧氏體晶粒的同時(shí)還使其混晶度降低;1000℃以上加熱奧氏體化時(shí),隨溫度的升高,晶粒粗化的同時(shí)其混晶度也隨之增加。
[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 偽 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 偽 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 偽 -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，

本文編號(hào)：2274522