| PANG Ming,ZHANG Xiao-han.Retardation of RuT300 End Pit Defects by Laser Melting[J],48(10):131-138 |
| Retardation of RuT300 End Pit Defects by Laser Melting |
| Received:January 22, 2019 Revised:October 20, 2019 |
| View Full Text View/Add Comment Download reader |
| DOI：10.16490/j.cnki.issn.1001-3660.2019.10.016 |
| KeyWord:laser melting pit defect numerical simulation Niyama criterion vermicular graphite cast iron temperature field |
| Author | Institution |
| PANG Ming |
School of Airport, Civil Aviation University of China, Tianjin , China |
| ZHANG Xiao-han |
School of Airport, Civil Aviation University of China, Tianjin , China |
|
| Hits: |
| Download times: |
| Abstract: |
| The work aims to break through the technical bottleneck of the laser melting ending pit defect on valve seat. A laser melting strengthening RuT300 three-dimensional transient temperature field simulation model was established and the influence of laser absorption, material phase change latent heat and parameters in thermal and physical properties were considered. Combining with Niyama criterion, the influence of laser parameter linear change on end pit defects was analyzed during end process of strengthening RuT300 by laser melting. In the process of laser melting ending, compared with the ending method without linear change of laser parameters, when the laser power was linearly decreased (the slope was –400), the maximum value of increased from the initial 0.0085 to 0.0097. When the slope decreased from –100 to –400, the maximum value of increased from the initial 0.0087 to 0.0097. When the laser scanning speed increased linearly (the slope was 20), the maximum value of increased from the initial 0.0087 to 0.0142. When the slope increased to 20 from 5, the maximum value of increases from the initial 0.0112 to 0.0142. With the linear decrease of laser power or the linear increase of laser scanning speed, the ending pit of laser melting valve seat had a decreasing trend, and with the increase of the absolute value of the slope in the linear decline of laser power or the increase of the slope in the linear rise of laser scanning speed, the ending pit had a decreasing trend. The results of experiment analysis and numerical simulation were basically consistent, which showed the validity of the model. In the process of laser melting ending, linear reduction of laser power or linear rise of laser scanning speed can be used to suppress the pitting defects at the end and improve the reliability of valve seat. |
| Close |
|
|
|