长时热暴露对镍铁基高温合金GH2070P组织和性能的影响  

Effect of Long-term Thermal Exposure on Microstructure and Performance of GH2070P Ferronickel-based Hi-temperature Alloy

作　　者：刘新星 龚巍 饶立文[1,2] 严靖博 刘鹏[3] 程义[1,2] LIU Xinxing;GONG Wei;RAO Liwen;YAN Jingbo;LIU Peng;CHENG Yi(State Key Laboratory of Low-carbon Thermal Power Generation Technology and Equipment,Harbin 150046,China;Harbin Boiler Co.,Ltd.,Harbin 150046,China;Xi’an Thermal Power Research Institute Co.,Ltd.,Xi’an 710032,China)

机构地区：[1]低碳热力发电技术与装备全国重点实验室,黑龙江哈尔滨150046 [2]哈尔滨锅炉厂有限责任公司,黑龙江哈尔滨150046 [3]西安热工研究院有限公司,陕西西安710032

出　　处：《钢管》2024年第3期19-23,共5页Steel Pipe

基　　金：黑龙江省自然科学基金项目(LH2022E075)。

摘　　要：对650℃参数锅炉用关键候选材料GH2070P镍铁基高温合金管在675℃进行1000、3000 h和5000 h的高温热暴露试验,对合金热暴露后的力学性能和微观组织演变情况进行分析。分析发现,GH2070P合金管在675℃高温热暴露1000 h后,晶内析出γ′相析出物,晶界析出M23C6型碳化物,合金室温拉伸强度、屈服强度和硬度明显增高,冲击韧性下降;随着热暴露时间继续增加至5000 h,γ′相尺寸发生粗化,γ′相的粗化符合LSW粗化理论,M23C6型碳化物尺寸略有增加,但仍断续分布在晶界处,未形成网状结构,合金室温拉伸强度、屈服强度和硬度稳定保持在较高的水平,冲击韧性下降速度减缓。The thermal exposure tests at 675℃and for 1000,3000 h and 5000 h respectively are conducted to the GH2070P ferronickel-based hi-temperature alloy tube as key candidate material for the boiler with 675℃parameter,and the post thermal exposure mechanical properties and microstructure evolutions of the alloy are investigated.The facts as fo-llows are revealed with the alloy tube as thermal exposed at 675℃and for 1000 hours.Theγ′phase is precipitated in grain and the M23C6 carbide phase is precipitated at grain boundary;the ambient temperature tensile strength,the yield strength and the hardness of the alloy are obviously increased,whereas it’s impact toughness goes down;along with the increase of thermal exposure time going up to 5000 h,the size of theγ′phase is coarsened,which is in alignment with the LSW coa-rsening theory;and the size of the M23C6 carbides are increased slightly,but are still presenting an intermittent distribution state at the grain boundary,and no network structure is formed;In general the ambient temperature tensile strength,the yield strength and the hardness of the alloy consistently keep at a rather high level,while its impact toughness reduction speed is getting slow.

关 键 词：镍铁基高温合金 高温热暴露 析出物 组织演变 力学性能 

分 类 号：TG132.3[一般工业技术—材料科学与工程]