高温临氢环境材料原位力学测试系统及其在高温合金中的应用  

In-situ Materials Mechanical Testing System under High-temperature Hydrogen Environment and Its Application

作　　者：周万成 孔帅 刘利强 孙彬涵 张显程[1] 涂善东[1] ZHOU Wan-cheng;KONG Shuai;LIU Li-qiang;SUN Bin-han;ZHANG Xian-cheng;TU Shan-tung(MOE Key Laboratory of Pressure Systems and Safety,School of Mechanical and Power Engineering,East China University of Science and Technology,Shanghai 200237,China)

机构地区：[1]华东理工大学机械与动力工程学院承压系统与安全教育部重点实验室,上海200237

出　　处：《分析测试学报》2024年第9期1324-1330,共7页Journal of Instrumental Analysis

基　　金：航空发动机及燃气轮机基础科学中心项目(P2022-C-III-002-001);国家自然科学基金委面上基金项目(52275147)。

摘　　要：该文设计并制造了一种高温临氢环境力学试验装置,可实现最高600℃以及2 MPa纯氢或混氢环境下材料的拉伸测试。该装置创新氢气环境箱设计,并配备真空及气体置换系统,可实现既定试验温度下高纯气体的压力控制。通过采用直线位移传感器,实现了对材料变形量的准确稳定测量。利用该装置评价了GH4169高温合金在不同温度临氢环境下的拉伸性能,结果表明,氢环境会对材料产生明显的脆化作用,主要体现在降低材料的延伸率及断面收缩率。利用扫描电子显微技术,对GH4169在不同温度临氢环境下的断裂模式及机制进行分析发现,GH4169在200℃下的氢致损伤更为严重,主要是因为氢原子在高温下的扩散速度较快,更易在晶界上聚集并诱发氢致沿晶断裂,进而使得材料塑性显著降低。Metallic materials can experience early damage formation and even catastrophic failure when subjected to loading under high-temperature hydrogen environment.The corresponding mechan⁃ical properties are,however,not widely reported due to the difficulty of performing environmental mechanical testing.Here an in-situ material mechanical testing system is designed to address this is⁃sue.This system is capable of performing tensile tests under either pure hydrogen or hydrogen mixed environment at temperatures up to 600℃and pressures up to 2 MPa.The facility features a hydrogen environment chamber equipped with vacuum,gas purging and heating systems.Deformation can be measured accurately by using a linear variable displacement transducer(LVDT)in combination with accurate sensors.The facility was utilized to assess the tensile performance of a GH4169 superalloy under various temperatures(25,200,400 and 600℃)in both pure gaseous hydrogen and pure gas⁃eous Ar environment.The findings highlight a significant embrittlement effect of the hydrogen envi⁃ronment on the material,reflected by the reduced elongation and reduction of area in compassion to the corresponding values under Ar.Analysis is further conducted using scanning electron microscopy(SEM)to investigate the fracture modes and hydrogen-induced damage mechanisms of the alloy test⁃ed under 25 and 200℃.It is concluded that hydrogen-induced damage in GH4169 is more severe at 200℃when compared with 25℃.This increased hydrogen sensitivity is primarily due to the acceler⁃ated diffusion of hydrogen atoms at high temperature,which leads to a faster hydrogen accumulation at grain boundaries and thereby a facile hydrogen-induced intergranular fracture.

关 键 词：氢损伤 高温 力学测试 高温合金 

分 类 号：O648.12[理学—物理化学] O741.1[理学—化学]