2.25Cr1Mo0.25V大钢锭热变形混晶组织的演变

Evolution of mixed grain structure on thermal deformation of 2. 25Cr1Mo0. 25V heavy steel ingot

参照实际热变形工艺,对2.25Cr1Mo0.25V钢锭进行了高温均匀化处理与热镦粗试验。研究了热变形条件对高温力学行为、粗晶组织的影响,得出了最佳的热力学参数。并且,着重对实际工艺中的混晶现象进行了判断分析并提出了预防措施。研究结果表明,对于2.25Cr1Mo0.25V加氢反应器用钢锭,热变形条件最佳参数为变形量20%、变形温度1150℃、应变速率0.1s-1。此时混晶比值D max/D0为3.1,最小几何晶粒尺寸D0为27～36μm,最大晶粒尺寸D max为99～136μm。随变形温度的升高、变形时间的延长,混晶结构逐渐消失。

Abstract： Referring to the actual thermal deformation process, the high-temperature homogenization treatment and hot upsetting experi- ment for 2. 25CrlMoO. 25V steel ingot were conducted. The influence of hot deformation conditions on high temperature mechanical behav- ior and coarse-grained tissue was studied, and the optimal thermaldynamie parameters were obtained. Then the mixed crystal phenomenon in actual process was mainly judged and analyzed, and the corresponding precautions were put forward. The results show that for the 2. 25CrlMoO. 25V steel ingot used for hydrogenation reactor, the optimal thermal deformation parameters are deformation of 20%, de- formation temperature of 1150℃ and strain rate of 0. 1 s-1. Meanwhile, the Dm=/Do is 3.1, Do is 27 -36 μm and Dmax is 99 - 136 μm. With the increasing of deformation temperatures and extension of deformation time, the mixed crystals gradually disappear.