資料載入中.....
|
請使用永久網址來引用或連結此文件:
http://ir.ncue.edu.tw/ir/handle/987654321/12263
|
| 題名: | Effect of residual stress on thermal fatigue in a type 420 martensitic stainless steel weldment |
| 作者: | Lin, Yi- Cheng;Chen, S. C. |
| 貢獻者: | 機電工程系 |
| 關鍵詞: | Welding;Residual stress;Thermal fatigue;Retained ferrite |
| 日期: | 2003-12
|
| 上傳時間: | 2012-07-05T07:10:13Z
|
| 出版者: | Elsevier Science B.V. |
| 摘要: | This paper aimed at the investigation of the effect of residual stress on thermal fatigue in martensitic stainless steel. In this study, a
submerged arc welding was utilized. In order to obtain the different magnitude of residual stresses, the parallel heat welding, vibration stress
relief, shot peening, and controlled low temperature stress relief processes were used for reduction of residual stresses due to welding. During
welding, the thermal cycle of different locations in weldment were recorded. The residual stresses were determined by using the hole-drilling
strain-gage method of ASTM standard E837. The retained ferrite content was determined with a digital optical microscope and image process
software. The experimental results showed that the residual stresses decrease with increase of thermal fatigue cycle number. This is because
that the formation of crack relieves residual stresses of specimen. Because of solidification structure difference, at low thermal fatigue cycle,
the density of cracks on near fusion line is the higher than centerline. At high thermal fatigue cycle, the density of crack from near fusion line is
lower than centerline, but very longer crack is found easily. The retained ferrite content and thermal fatigue crack tendency exist a critical
value. The retained ferrite less than about 31.5 vol.% will increase crack propagation tendency. The retained ferrite become a harmful factor
for crack propagation tendency when the retained ferrite more than this critical content. It is because that too much ferrite content in
martensitic matrix may result in a lower strength structure and crack can propagate easily. In addition, the dual phase structure may introduce
more harmful interior stress due to different volume shrinkage between retained phase and matrix. |
| 關聯: | Journal of Material Processing Technology, 138: 22-27 |
| 顯示於類別: | [機電工程學系] 期刊論文
|
文件中的檔案:
| 檔案 |
大小 | 格式 | 瀏覽次數 |
|---|
| index.html | 0Kb | HTML | 712 | 檢視/開啟 |
|
在NCUEIR中所有的資料項目都受到原著作權保護.
|
