回火次數對P91焊管接頭力學性能的影響

王超; 黨文靜; 魯路; 王瑜; 崔征; 王偉博

doi:10.13374/j.issn2095-9389.2017.04.007

回火次數對P91焊管接頭力學性能的影響

doi: 10.13374/j.issn2095-9389.2017.04.007

王超^1,2,
黨文靜^1,2, ,,
魯路^1,2,
王瑜³,
崔征¹,
王偉博¹

1) 西安建筑科技大學冶金工程學院, 西安 710055
2) 陜西省冶金工程技術研究中心, 西安 710055
3) 陜西省鍋爐壓力容器檢驗所, 西安 710048

基金項目:

國家質檢總局科技計劃資助項目(SNQTS_2013QK148)

詳細信息

中圖分類號: TG156.5
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出版歷程
- 收稿日期: 2016-07-11

Influence of tempering times on the mechanical properties of P91 weld joints

WANG Chao^1,2,
DANG Wen-jing^{1,2
, ,},
LU Lu^1,2,
WANG Yu³,
CUI Zheng¹,
WANG Wei-bo¹

1) School of Metallurgical Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China
2) Shanxi Province Metallurgical Engineering and Technology Research Center, Xi'an 710055, China
3) Shanxi Institute of Inspection on Boiler & Pressure Vessel, Xi'an 710048, China

摘要

摘要: 采用光學顯微鏡、X射線衍射分析、透射電鏡、選區電子衍射及常溫與高溫拉伸試驗等檢測手段,基于不同回火次數下P91焊接接頭顯微組織的演化過程研究其對力學性能的影響.結果表明,隨著回火次數的增多,接頭顯微組織主要保留了板條馬氏體位向的回火索氏體,主要相為α-Fe相和Fe-Cr相,熱影響區的室溫及高溫強度先增大后減小.在回火一次時,彌散析出的MX (M=V/Nb,X=C/N)型碳氮化物、位錯纏結及亞穩態的位錯網對接頭有一定的析出強化及位錯強化作用,其力學性能較佳,高溫抗拉強度達最大值232.66 MPa;隨著回火次數進一步增多,離散分布的碳化物Cr₂₃C₆逐漸偏聚并在晶界處演化為串鏈狀分布,使晶界脆化,強度降低,但韌性有所改善.
- 無縫管 /
- 焊接接頭 /
- 回火 /
- 微觀組織 /
- 高溫力學性能
Abstract: The P91 weld joint used in the experiment is re-tempered according to the heat treatment process. The effect of tempering times on its mechanical properties, including that at room temperature and high temperature, was then investigated in relation to the evolution of its microstructure using optical microscopy (OM), X-ray diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED), and tensile tests. Results indicate that the strength at room and high temperature of the heat affected zone increases first and then decreases with an increase in tempering times. In addition, the microstructure is still tempered sorbite that reserves the orientation of lath martensite, and the main phases are the α-Fe phase and Fe-Cr phase. After being tempered once, its high-temperature tensile strength reaches a maximum of 232.66 MPa. These improved mechanical properties relate to the dispersed distribution of niobium and vanadium carbonitride precipitate particles, dislocation tangles, and dense metastable dislocation networks. With the increase of tempering times, the distribution of Cr₂₃C₆ precipitates gradually undergoes a change from being isolated to displaying a continuous manner in the grain boundaries; this can embrittle the grain boundary and reduce the strength while improving toughness.
- seamless pipe /
- weld joints /
- tempering /
- microstructure /
- high temperature mechanical properties

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參考文獻(7)

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