摘要
使用25 Hz振动频率、2 mm振幅、100 MPa摩擦压力和150 MPa顶锻压力的工艺参数对GH4169合金和S31042钢进行线性摩擦焊连接,通过OM、SEM和TEM分析异质接头的组织特征,并进行拉伸、硬度和蠕变实验测试异质接头在室温和高温环境下的力学性能。结果表明,GH4169合金与S31042钢的连接界面在线性摩擦焊过程中发生动态再结晶,形成无孔无裂纹的冶金结合,同时焊缝区在高温和应力作用下形成大量弥散分布的强化相颗粒。通过细晶强化和析出强化的综合作用,异质接头的抗拉强度高于S31042钢,焊缝区的硬度明显高于2种母材。
S31042 steel is a typical 25Cr-20Ni type austenitic heat-resistant steel with excellent resistance to oxidation and creep rupture strength near 600 ℃. This austenitic steel is widely used as a super-heater or re-heater in ultra-super critical plants with steam specifications as high as 600 ℃ and 25 MPa. To reduce CO2 emissions and improve power generation, the application of advanced ultrasuper critical plants(steam parameters 700 ℃ and 30 MPa) can be promoted. Owing to its excellent mechanical properties as well as good corrosion resistance at elevated temperature above 650 ℃, GH4169 alloys have the potential to be used in advanced ultra-super critical plants. Practically, it is meaningful to investigate the welding process of GH4169/S31042 dissimilar materials. In this work, the joint between dissimilar materials(S31042/GH4169) was studied by linear friction welding, and the microstructures and mechanical properties of the joint were investigated by OM, SEM, TEM, hardness testing, tensile testing,and creep testing at 700 ℃. Good metallurgic bonding was obtained under the optimized welding process parameters of 25 Hz(frequency), 2 mm(amplitude), 100 MPa of frictional pressure, and 150 MPa of forging pressure. Dynamic recrystallization occurred and the secondary phase particles precipitated within the weld zone. The microhardness of the welded joint was higher than that of the base metal, and the tensile properties of the joint were higher than S31042 steel, which is attributed to both fine grain and dispersion strengthening.
作者
李彦默
郭小辉
陈斌
李培跃
郭倩颖
丁然
余黎明
苏宇
李文亚
LI Yanmo;GUO Xiaohui;CHEN Bin;LI Peiyue;GUO Qianying;DING Ran;YU Liming;SU Yu;LIWenya(Luoyang Ship Material Research Institute,Luoyang 471000,China;School of Materials Science and Engineering,Tianjin University,Tianjin 300354,China;School of Materials Science and Engineering,Northwestern Polytechnical University,Xi'an 710072,China)
出处
《金属学报》
SCIE
EI
CAS
CSCD
北大核心
2021年第3期363-374,共12页
Acta Metallurgica Sinica
基金
国家自然科学基金项目No.U1660201。
