腐食環境下における高強度鋼の微小表面き裂進展特性 : 第1報, 微小き裂におけるK_<ISCC>の低下に起因する疲労き裂進展の加速

概要

論文の詳細を見る
The growth characteristics of small fatigue cracks in room air, dry air and 1%NaCl solution were investigated for a high-strength steel, SNCM439. The growth rates of small fatigue cracks in room air accelerated slightly in contrast to long cracks, owing to the vapor in the air. The growth characteristics of small cracks in dry air were equivalent to those of long cracks. On the other hand, small cracks in a 1%NaCl solution showed a marked acceleration in fatigue crack growth as compared with long cracks. This was caused by the decrease of the threshold value of stress corrosion cracking (K_<ISCC>), that is, K_<ISCC> lowered with decreasing the crack length. The acceleration of small fatigue cracks in a 1%NaCl solution was predicted by the superposition method. Consequently, the predicted crack growth rates agreed well quantitatively with the experimental results.
一般社団法人日本機械学会の論文
1990-04-25