Effect of Work-Hardened Layer and Humidity on Step-Wise S-N Curve in a High Strength Steel、Corrosion Fatigue Crack Initiation and Early Growth Behavior in a Ferritic Stainless Steel、機械構造物の減衰能に及ぼす充てん粒子の影響、クラッド材深絞り容器壁部の増肉しごきによる厚肉化