中温变形对2.25Cr-1Mo-0.25V钢蠕变行为及组织演化的影响  

Effect of warm deformation on creep behavior and microstructure evolution of 2.25Cr-1Mo-0.25V steel

作　　者：李尤 黄淞 陈志平[3] LI You;HUANG Song;CHEN Zhiping(Department of Mechanical Engineering,Jiaxing University,Jiaxing 314001,Zhejiang,China;School of Mechanical and Power Engineering,East China University of Science and Technology,Shanghai 200237,China;Institute of Process Equipment,Zhejiang University,Hangzhou 310027,Zhejiang,China)

机构地区：[1]嘉兴大学机械工程系,浙江嘉兴314001 [2]华东理工大学机械与动力工程学院,上海200237 [3]浙江大学化工机械研究所,浙江杭州310027

出　　处：《钢铁》2025年第1期123-136,共14页Iron and Steel

基　　金：国家自然科学基金资助项目(52375143,52405156);新疆自然科学基金资助项目(2024D01A117)。

摘　　要：2.25Cr-1Mo-0.25V钢制厚壁结构广泛应用于石油化工、能源电力等领域,如加氢反应器主体、核反应堆管道等。由于长期服役于高温高压环境,蠕变破坏是2.25Cr-1Mo-0.25V钢制厚壁结构最主要的失效模式之一,而中温变形作为其关键制造技术对2.25Cr-1Mo-0.25V钢的蠕变性能具有重要影响。为探明中温变形对2.25Cr-1Mo-0.25V钢蠕变性能与组织演化的作用规律,通过650℃拉伸预变形,482℃/350 MPa蠕变试验,OM、SEM、TEM、EDS、EBSD、3Dμ-XCT等测试手段,研究了0~10%内不同应变量的中温变形对2.25Cr-1Mo-0.25V钢蠕变断裂寿命、微观组织结构及蠕变期间碳化物、晶粒形貌、Schmid因子、孔洞损伤等组织演化的影响规律。蠕变试验结果表明,中温变形会明显削弱2.25Cr-1Mo-0.25V钢的蠕变性能,且随应变量从0增加到10%,2.25Cr-1Mo-0.25V钢的蠕变断裂寿命从989 h单调下降至57 h,降幅达95%。组织表征结果表明,中温变形会促使2.25Cr-1Mo-0.25V钢内碳化物发生粗化,且其粗化程度随应变量增加而增大。此外,中温变形也加剧2.25Cr-1Mo-0.25V钢蠕变期间的组织退化,主要表现为482℃、350 MPa条件下碳化物更易长大、粗化和偏聚,晶粒硬度下降且更早出现塑性变形,孔洞损伤发展更快。分析认为,中温变形加速2.25Cr-1Mo-0.25V钢蠕变失效的主要原因是其碳化物热稳定性降低,削弱了固溶强化和沉淀强化效果,同时更多软取向晶粒形成,加剧了碳化物与周围基体的塑性响应不匹配,为位错运动与蠕变孔洞萌生提供了有利条件。该研究可为2.25Cr-1Mo-0.25V钢制厚壁结构长期服役完整性评价提供一定的理论指导。2.25Cr-1Mo-0.25V steel thick-walled structures are extensively utilized in petrochemical,energy,and electric power industries,encompassing applications such as hydrogenation reactors,nuclear reactor pipelines,etc.Due to prolonged operation under harsh environments,creep failure is a predominant mode of failure observed in 2.25Cr-1Mo-0.25V steel thick-walled structures.Warm deformation,a key fabricating technology of 2.25Cr-1Mo-0.25V steel thick-walled structures,inevitably changes the creep property of 2.25Cr-1Mo-0.25V steel,but its detailed effect still remains obscure.The impact of warm deformation on the creep behavior and microstructure degradation of 2.25Cr-1Mo-0.25V steel was experimentally investigated.First,a series of creep rupture tests were carried out under 482℃and 350 MPa,in which test materials were extracted from a 152 mm thick plate and subjected to pre-strain ranging from 0 to 10%under 650℃.Meanwhile,a series of creep interruption tests were performed under 482℃and 350 MPa,in which test materials were extracted from 0 and 6%650℃pre-strained materials.Thereafter,the microstructures of test materials were analyzed by various characterization techniques,such as OM,SEM,TEM,EDS,EBSD and 3Dμ-XCT.Finally,warm deformation induced microstructure degradation as well as their implication for creep behavior and damage evolution was discussed in detail.Creep rupture tests show that warm deformation leads to a significant decrease in creep properties,and as the 650℃pre-strain increases from 0 to 10%,the creep rupture life decreases monotonically from 989 h to 57 h,a decrease of 95%.Moreover,microstructural observations demonstrate that warm deformation promotes carbide coarsening which increases with increasing 650℃pre-strain.Also,warm deformation aggravates creep microstructure degradation,including easier carbide coarsening,earlier grain deformation,faster void increasing,etc.Integrative analysis suggests that warm deformation induced carbide behavior weakens the effects of solid solution streng

关 键 词：2.25CR-1MO-0.25V钢 中温变形 蠕变断裂 组织演化 孔洞损伤 厚壁结构 钢铁材料 长期服役 

分 类 号：TG142.1[一般工业技术—材料科学与工程]