预时效处理对冷轧含Al奥氏体耐热钢组织和性能的影响  

Effect of Pre-Aging on Microstructure and Properties of Cold-Rolled Alumina-Forming Austenitic Steel

作　　者：张胜煜 马庆爽 余黎明[4] 张竟文 李会军 高秋志 ZHANG Shengyu;MA Qingshuang;YU Liming;ZHANG Jingwen;LI Huijun;GAO Qiuzhi(School of Materials Science and Engineering,Northeastern University,Shenyang 110819,China;School of Resources and Materials,Northeastern University at Qinhuangdao,Qinhuangdao 066004,China;CNPC Bohai Equipment Manufacturing Co.Ltd.,Tianjin 300457,China;School of Materials Science and Engineering,Tianjin University,Tianjin 300354,China;Faculty of Engineering and Information Sciences,University of Wollongong,Wollongong,NSW 2522,Australia)

机构地区：[1]东北大学材料科学与工程学院,沈阳110819 [2]东北大学秦皇岛分校资源与材料学院,秦皇岛066004 [3]中国石油集团渤海石油装备制造有限公司,天津300457 [4]天津大学材料科学与工程学院,天津300354 [5]Faculty of Engineering and Information Sciences,University of Wollongong,Wollongong,NSW 2522,Australia

出　　处：《金属学报》2025年第1期177-190,共14页Acta Metallurgica Sinica

基　　金：国家自然科学基金项目Nos.52171107和52201203;驻冀高校与石家庄市产学研合作项目No.241791237A。

摘　　要：含Al奥氏体耐热(AFA)钢有望应用于超超临界火电机组高温部件,但其高温强度和稳定性目前还有待于进一步提高。本工作研究了预时效处理对冷轧含Al奥氏体耐热钢的析出行为、组织演变和力学性能的影响。结果表明,预时效显著影响了冷轧AFA钢在高温时效过程中的位错强化与析出强化的协同强化机制。预时效试样中的纳米析出相对晶界和位错具有较强的钉扎作用,可增加形核位置及相变驱动力,从而增强了析出强化作用。与冷轧10%试样相比,预时效24 h+冷轧试样中的Laves相和B2-NiAl相对晶界和位错具有更强的钉扎作用,有效阻碍了位错滑移,导致局部应力集中,为析出相的形成提供更多的形核位置及相变驱动力,加速了相转变过程,析出相的体积分数显著提升。冷轧和预时效+冷轧均使得材料的强度和硬度呈现先升高后降低的趋势。Alumina-forming austenitic(AFA)steel is expected to be applied to high-temperature components of ultra-supercritical thermal power plants.However,the high-temperature strength and stability of AFA steel need to be improved further.Here,the influence of pre-aging on the precipitation behavior,microstructural evolution,and mechanical properties of cold-rolled AFA steel was investigated.The results showed that pre-aging significantly influences the synergistic strengthening due to dislocations and precipitation in cold-rolled AFA steel during the process of high-temperature aging treatment.The precipitates in a sample that received pre-aging treatment exhibited strong pinning effect on grain boundaries and dislocations,which enhances the effect of precipitation strengthening by boosting the number of nucleation sites and the driving force for the formation of the precipitates.Compared to cold rolling with a 10%thickness reduction but without pre-aging,the formation of the Laves phase and the B2-NiAl phase after pre-aging for 24 h resulted in increased pinning on the dislocations and grain boundaries,which prevented dislocation slip,generated stress concentrations,boosted the number of nucleation sites and the driving force for the formation of the precipitates,and accelerated the phase-transition process;the volume fraction of the precipitates also increased significantly.Hardness and tensile tests at room temperature showed that the strength and hardness resulting from both cold rolling and cold rolling after preaging first increased and subsequently decreased.

关 键 词：预时效 冷轧 含Al 奥氏体耐热钢 微观组织演变 力学性能 

分 类 号：TG156[金属学及工艺—热处理] TG142.73[金属学及工艺—金属学]