| About this Abstract |
| Meeting |
MS&T21: Materials Science & Technology
|
| Symposium
|
New Frontiers in Physical Metallurgy of Steels
|
| Presentation Title |
Relationship between Fatigue Strength and Microstructure of Carburized Steel Tempered at Different Temperature |
| Author(s) |
Takuya Kita, Kazumasa Yasuda, Junya Asaoka, Goro Miyamoto, Tadashi Furuhara |
| On-Site Speaker (Planned) |
Takuya Kita |
| Abstract Scope |
The relationship between fatigue strength and microstructure of carburized SCM415 steel tempered at 120-350℃ for 1h is evaluated with rotating bending fatigue test pieces. When tempering temperature is above 180 ℃, fatigue strength as well as hardness decreases with increasing temperature. On the other hand, when tempering temperature is below 180 ℃, the fatigue strength decreases at lower temperature in spite of the increase in hardness. The amount of carbide precipitation increases and the dislocation density decreases with increasing tempering temperature, which leads to softening. Fracture surface analysis of the specimens underwent fatigue tests revealed that crack initiated at the prior austenite grain boundary at the tempering below 180 ℃. This is probably due to the stress concentration on the grain boundary caused by the high intragranular hardness or the decrease in the grain boundary strength caused by solute segregation and carbide precipitation at the grain boundary. |