阴极充氢对结构钢裂尖形变行为的影响

Influence of Cathodic Hydrogen Charging on Plastic Deformation Behaviour at Crack Tip of Structure Steel

采用微机控制激光散斑干涉技术，原位研究了结构钢单边缺口预裂纹试样在３．５％Ｎａｄ水溶液中，－１４００ｍＶ（ＳＣＥ）电位下阴极完氢６小时前后，裂尖材料形变行为的变化。同时，还对充氢与未充氢条件下光滑圆柱试样的应力－应变行为进行了对比研究，用扫描电镜观察了断口形貌。结果表明：由于氢的进入，使材料的加工硬化程度加剧，从而导致了变形困难。

A computerized digital speckle-interferometry system was set up to study the influence of cathodic hydrogen charging on the plastic deformation behaviour at corrosion fatigue crack tip for the single edge notched plate specimens of structure steel in 3. 5% NaCl solution with an applied potential of -1400mV (SCE). Meanwhile, the monodirection tension tests with smooth specimens were performed in both air and 3. 5%NaCl solution under the hydrogen charging conditions. The fracture surface morphology from corrosion fatigue and tension was examined by SEM. The experimental results showed that the existence of hydrogen in crack tip material caused an increase of both yield strength and hardening exponent and a decrease of plastic zone size at the corrosion fatigue crack tip.