3.5% NaCl 水溶液의 pH變化가 複合組織鋼의 腐蝕疲勞破壞에 미치는 影響

다국어 초록 (Multilingual Abstract)

Corrosion fatigue fracture of dual phase steel(SS41) and raw material steel(SS41) were investigated in 3.5% NaCl aqueous solution at pH 4, 6, 9 and 11.<br/>
The fatigue limit of dual phase steel is increased approximately 1.8 times larger than that of raw material in air. The corrosion fatigue life of dual phase steel is about 5~10 times larger than that of raw material in 3.5% NaCl aqueous solution. The reduction of fatigue life is larger for the acid salt solution than for the alkali salt solution. The reduction of fatigue life of dual phase steel by the change of pH is smaller than that of raw material. The influence of stress level on the reduction ratio of corrosion fatigue life is large at pH 6~11.<br/>
The reduction ratio of corrosion fatigue life of dual phase steel and raw material is nearly coincided at pH 2. While at pH4~2 the reduction ratio of corrosion fatigue life only depends on the corrosion effect. It has been found that the corrosion resistance effect of dual phase steel is smaller than that of raw material in corrosion fatigue crack propagation rate.<br/>
As pH below 6 is changed, it can be clearly observed from raw material that the brittle intergranular fracture is characterized, and from the above result, the influence of corrosion of dual phase steel is small.