高窒素 9Cr-2Co 鋼の高温クリープ変形機構

概要

論文の詳細を見る
The role of nitrogen, which was forcibly introduced up to 0.2mass% to a 9Cr-2Co steel, was investigated in a quasi-steady state creep in the range of stress and temperature from 873 to 1000K and 70 to 100MPa. The analysis showed that the stress exponent of quasi-steady state creep rate was about 5 irrespective of nitrogen concentration. Mechanical differential tests conducted during the quasi-steady state creep revealed that there was no instantaneous plastic strain on an abrupt stress change regardless of soluble nitrogen concentration from 240 to 410ppm and the effective stress exponent of average dislocation velocity was nearly equal to unity. The dislocation density determined from the differential tests proved to be raised with the 3.5 to 4th power of applied stress. This larger stress exponent was reduced to 1.8 to 2.6 when an elementary addition rule was taken into account between an internal stress component from precipitates and a dislocation-dislocation interaction. The reduced stress exponent whose origin was ascribable to the dislocation-dislocation interaction was compatible with the stress exponent of single phase materials. These results suggest that the dislocations drag I-S (Interstitial-Substitutional) atmospheres behind them although a large fraction(about 90%) of internal stress in flow stress and their stress exponents of the quasi-steady state creep are both favorable to the metal type behavior of creep.
社団法人日本鉄鋼協会の論文
1996-12-01

高窒素 9Cr-2Co 鋼の高温クリープ変形機構

スポンサーリンク

概要

著者

関連論文

スポンサーリンク