摘要
对650℃超超临界锅炉用候选材料GH2070P合金管在675℃进行不同应力水平的高温持久试验,基于等温线法预测10万h的高温持久强度,分析了不同高温持久时间的微观组织演变情况和断口情况。研究发现,基于目前的试验数据,热轧GH2070P合金管在675℃温度外推10万h的持久强度为141 MPa,满足设计目标要求;随着持久时间的增加,γ'相尺寸逐渐粗化,符合LSW规律。大量弥散分布的球状γ'相对位错有很强的钉扎作用,使GH2070P合金具有较好的高温强度和持久强度;晶界析出断续的M_(23)C_6型碳化物,未形成网状结构;高温持久试验断口表现为高温蠕变导致的沿晶断口,在试样沿晶断裂时发生了微观上的塑性变形。
An investigation is conducted on the candidate material GH2070P alloy tube for the 650℃ultra supercritical boiler service by performing the high-temperature creep rupture tests at 675℃under various stress levels.The isothermal method is employed to predict the 100000 h high-temperature creep strength.The microstructure evolution and the fracture characteristics at different durations of high-temperature creep are analyzed.It is revealed via the study that based on the existing data from the test the extrapolated 100000 h creep strength of the GH2070P alloy tube at 675℃is 141 MPa,meeting the design target requirements;along with the increase of the creep duration,the size ofγ'phase gradually coarsens,conforming to the LSW law;a great number of finely dispersed sphericalγ'phases have a strong pinning effect on the relative dislocations,providing the GH2070P alloy with good high-temperature strength and creep strength;the M23C6 carbides precipitated at the grain boundary in the GH2070P alloy form no network structure;the fracture surfaces of the GH2070P alloy after the high-temperature creep-rupture tests exhibit intergranular fractures as caused by the hi-temperature creep accompanied by micro-plastic deformation during the intergranular fracture of the specimens.
作者
刘新星
饶立文
严靖博
刘鹏
程义
LIU Xinxing;RAO Liwen;YAN Jingbo;LIU Peng;CHENG Yi(State Key Laboratory of Low-carbon Thermal Power Generation Technology and Equipments,Harbin Boiler Co.,Ltd.,Harbin 150046,China;Xi’an Thermal Power Research Institute Co.,Ltd.,Xi’an 710032,China)
出处
《钢管》
2025年第3期18-21,共4页
Steel Pipe
基金
黑龙江省自然科学基金项目(LH2022E075)。
关键词
超超临界
GH2070P合金
持久强度
组织演变
ultra-supercritical
GH2070P alloy
creep-rupture strength
microstructure evolution
