Effect of Aging Treatment on Properties and Post-weld Microstructure of Stainless Steel Containing Niobium  

时效对含铌不锈钢性能及焊后组织的影响

作　　者：Liu Tianzeng Zhao Yanchun Chen Anzhong Yu Zhiqi Feng Li Li Jucang Pan Jixiang 刘天增;赵燕春;陈安忠;于志琦;冯力;李具仓;潘吉祥(兰州理工大学省部共建有色金属加工与再利用国家重点实验室,甘肃兰州730050;甘肃酒钢集团宏兴股份有限责任公司,甘肃嘉峪关735100)

机构地区：[1]State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals,Lanzhou University of Technology,Lanzhou 730050,China [2]Gansu Jiu Steel Group Hongxing Iron&Steel Co.,Ltd,Jiayuguan 735100,China

出　　处：《稀有金属材料与工程》2025年第1期39-49,共11页Rare Metal Materials and Engineering

基　　金：Science and Technology Program Project of Gansu Province(21ZD3GB001)。

摘　　要：The effects of different aging processes on the precipitated phase,mechanical properties,molten salt corrosion resistance and post-weld microstructure of 347H stainless steel were studied.The results show that a large number of precipitated phases appear in the crystal after aging at 700℃for 400 h.After aging for 3000 h,the number of precipitated phases increases and most of them are gathered at the grain boundaries.There are two forms of precipitates,one is the coarse precipitate rich in Cr,and the other is the smaller precipitates mainly consisting of NbC.After aging at 700℃for 30 min,the yield strength and tensile strength of the samples at room temperature and 593℃increase,but the elongation decreases.The corrosion results in nitrate at 565℃show that the corrosion products of the aged samples are the same as that of the original samples,which are Fe_(2)O_(3),Fe_(3)O_(4),MgCr_(2)O_(4),MgFe_(2)O_(4),FeCr_(2)O_(4) and NaFeO_(2).The proportion of Fe_(3)O_(4) that is dense and well bonded to the subtrate in the original sample is higher than that in the aged sample,so the corrosion resistance is better.At 700℃,the aging time has no obvious effect on the microstructure after welding.研究了不同时效工艺对347H不锈钢析出相、力学性能、耐熔盐腐蚀性能和焊后组织的影响。结果表明,700℃时效400 h后,晶体内部会出现大量析出相;时效3000 h后,析出相数量增多,并大量聚集在晶界处;析出物有2种形态,其中粗大的析出物富含Cr,而较小的析出物以NbC为主。700℃时效30 min后,试样在室温和593℃时的屈服强度以及抗拉伸强度均升高,但延伸率降低。在565℃硝酸盐中的腐蚀结果表明,老化试样与原始试样的腐蚀产物相同,均为Fe_(2)O_(3)、Fe_(3)O_(4)、MgCr_(2)O_(4)、MgFe_(2)O_(4)、FeCr_(2)O_(4)和NaFeO_(2)。原始试样中致密均匀、与基体结合较好的Fe_(3)O_(4)的比例高于时效试样,因此耐腐蚀性较好。在700℃时,时效时间对焊后组织无明显影响。

关 键 词：AGING 347H stainless steel precipitated phase mechanical properties molten salt corrosion welding property 

分 类 号：TG156.92[金属学及工艺—热处理] TG142.71[金属学及工艺—金属学]