文献类型：期刊文献

中文题名：中温变形对2.25Cr-1Mo-0.25V钢蠕变行为及组织演化的影响

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

作者：李尤[1];黄淞[2];陈志平[3]

机构：[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

年份：2025

卷号：60

期号：1

起止页码：123

中文期刊名：钢铁

外文期刊名：Iron and Steel

收录：;EI(收录号：20253419020741);北大核心:【北大核心2023】；

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)。

语种：中文

中文关键词：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

外文关键词：2.25Cr-1Mo-0.25V steel;warm deformation;creep failure;microstructure evolution;void defect;thick-walled structure;iron and steel material;long-term service

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 strengthening and precipitation strengthening as well as softens the grain matrix,which increases the mismatch in the plastic response between carbides and its surroundings and thus accelerates the movement of dislocations and the formation of void defects.Their combined action appears to accelerate the creep fracture behavior of 2.25Cr-1Mo-0.25V steel.It could provide theoretical guidance for the long-term service integrity assessment of 2.25Cr-1Mo-0.25V steel thick-walled structures.