[論文] 高張力鋼의 腐飾疲勞에 關한 硏究

다국어 초록 (Multilingual Abstract)

In case of K_lmax < K_lscc, the corrosion fatigue of high strength steel in O.1N H₂SO₄ solution and 3.5% salt water is as follows.<br/>
1. The fatigue life shortens in order of 3.5% salt water and O.1N H₂SO₄ solution.<br/>
2. The fatigue crack growth rate in air is obtained as the following equation.<br/>
(dc/dN)_?=7.23×10^-?(△K)^?<br/>
3. The corrosion fatigue crack growth rate in environment is divided into three regions, that is, First Region, Second Region and Third Region from the small cyclic stress intensity.<br/>
4. The formation rate of the active surface on metal is slower than the mechano-chemical reaction rate in First Region. The crack growth rate depends on time and the cyclic stress intensity and is expressed as the following equation.<br/>
(dc/dN)=C(△K)^δ<br/>
5. The formation rate of the active surface is faster than the mechano-chemical reaction rate in Second Region and the synergistic effect by stress and corrosion becomes slow. In case the. fatigure load is large, we have the critical crack growth rate which is not<br/>
related to the cyclic stress intensity. .<br/>
6. The corrosion crack growth rate by the mechano-chemical reaction is the same in H₂S0₄ solution and salt water, so Hydrogen accelerates the crack growth.<br/>
7. The environment has no effect on the corrosion. fatigue crack growth rate in Third Region.<br/>
8. In First Region and Second Region, dimple is observed on the fatigue fracture surface in O.lN H₂SO₄ solution.<br/>
9. The striation is observed in any environment as in air in Third Region and its interval approximately coincide with the crack growth rate.

목차 (Table of Contents)

• Abstract
  
• 1.序論
  
• 2.材料 및 實驗方法
  
• 3.實驗結果 및 考察
  
• 4.結論
  
• 後記
  
• 參考文獻