Rights statement: This is the author’s version of a work that was accepted for publication in International Journal of Pressure Vessels and Piping. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in International Journal of Pressure Vessels and Piping, 198, 2022 DOI: 10.1016/j.ijpvp.2022.104681
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Final published version
Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
}
TY - JOUR
T1 - Laser additive manufacturing and post-heat treatment on microstructure and mechanical properties of 9Cr steel
AU - Feng, Junyi
AU - Zhang, Peilei
AU - Jia, Zhiyuan
AU - Yu, Zhishui
AU - Fang, Chao
AU - Yan, Hua
AU - Shi, Haichuan
AU - Tian, Yingtao
AU - Xie, Fan
N1 - This is the author’s version of a work that was accepted for publication in International Journal of Pressure Vessels and Piping. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in International Journal of Pressure Vessels and Piping, 198, 2022 DOI: 10.1016/j.ijpvp.2022.104681
PY - 2022/8/31
Y1 - 2022/8/31
N2 - 9Cr steel is a material that has been widely used in pressure vessel parts in thermal power plants and nuclear power plants, and has good high-temperature creep properties. Laser Melting Deposition (LMD) is a promising method for preparing complex 9Cr steel components. It provides a rare opportunity to improve existing designs and produce fine features and complex geometries with higher efficiency. The LMD-9Cr steel sample has high density, the maximum tensile strength of the sample is 1057.75 MPa, which is much higher than the standard cast 9Cr steel of 650 MPa. We use 760 °C tempering heat treatment, after heat treatment, the average grain size of the material is reduced, the Charpy impact performance is improved, and the tensile strength and microhardness are slightly reduced. Although the tempering heat treatment greatly reduces the average grain size of the sample by 35.59%, but at the same time the tempering heat treatment greatly reduces the high dislocation density of lath martensite, and the supersaturation behavior of Cr, W and C elements weakens the effect of solid solution strengthening. In addition, through the nanoindentation test, we found that although the M23C6 precipitated phase can harden the material, at the micro level, the elastic modulus and nano-hardness of the precipitated phase are lower than that of the homogeneous phase.
AB - 9Cr steel is a material that has been widely used in pressure vessel parts in thermal power plants and nuclear power plants, and has good high-temperature creep properties. Laser Melting Deposition (LMD) is a promising method for preparing complex 9Cr steel components. It provides a rare opportunity to improve existing designs and produce fine features and complex geometries with higher efficiency. The LMD-9Cr steel sample has high density, the maximum tensile strength of the sample is 1057.75 MPa, which is much higher than the standard cast 9Cr steel of 650 MPa. We use 760 °C tempering heat treatment, after heat treatment, the average grain size of the material is reduced, the Charpy impact performance is improved, and the tensile strength and microhardness are slightly reduced. Although the tempering heat treatment greatly reduces the average grain size of the sample by 35.59%, but at the same time the tempering heat treatment greatly reduces the high dislocation density of lath martensite, and the supersaturation behavior of Cr, W and C elements weakens the effect of solid solution strengthening. In addition, through the nanoindentation test, we found that although the M23C6 precipitated phase can harden the material, at the micro level, the elastic modulus and nano-hardness of the precipitated phase are lower than that of the homogeneous phase.
KW - Laser melting deposition (LMD)
KW - 9Cr steel
KW - Different powder size
KW - Post-heat treatment
KW - Mechanical properties
KW - Microstructure
U2 - 10.1016/j.ijpvp.2022.104681
DO - 10.1016/j.ijpvp.2022.104681
M3 - Journal article
VL - 198
JO - International Journal of Pressure Vessels and Piping
JF - International Journal of Pressure Vessels and Piping
SN - 0308-0161
M1 - 104681
ER -