Cailiao Baohu (Feb 2023)

Effects of Magnetic Mark Display on Mechanical Properties of Laser-Enhanced 17-4PH Blades

  • HAN Liang, GONG Wei-xing, FENG Tian-shu, WANG Jian-ze

DOI
https://doi.org/10.16577/j.issn.1001-1560.2023.0048
Journal volume & issue
Vol. 56, no. 2
pp. 170 – 174

Abstract

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In order to enhance the corrosion resistance of the 17-4PH low-pressure last stage blades，the steam inlet side of the 17-4PH blades needs to be treated with laser-enhanced solid solution.The last stage blades treated with laser solution often show obvious magnetic marks in the subsequent magnetic particle inspection.Optical microscope，scanning electron microscope，X-ray diffractometer，electron probe and other analytical means were used to prove that the reason for the appearance of magnetic marks at the boundary of the laser solid solution region was a large number of austenite structures that appeared at the boundary，which reduced the permeability at the boundary of the laser solid solution region.Besides，the residual stress of laser solid solution blade was determined as compressive stress by XRD，and the three-point bending fatigue test showed that the R＝0.1 fatigue limit of 17-4PH blade could be increased from 750 MPa to 860 MPa by laser-enhanced solid solution.

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