【摘要】 采用动电位扫描、慢应变拉伸(SSRT)和扫描电镜观察研究了温度和外加电位对X70管线钢在成都土壤模拟溶液中的应力腐蚀行为的影响。结果表明,在不同温度和不同电位下,X70管线钢在土壤模拟溶液中表现出不同的应力腐蚀敏感性。在温度和外加电位的交互试验中,电位的变化对X70管线钢在成都土壤模拟溶液中的应力腐蚀敏感性的影响占主导地位,应力腐蚀敏感性在不同温度下的变化趋势保持一致。在-450 m V(vs SCE,下同)的阳极电位下,SCC的机理为阳极溶解;在-850 m V电位下,阴极保护作用抑制了阳极溶解;当电位负移至-1200 m V时,表现出较强的应力腐蚀敏感性,SCC机理以氢脆为主。温度对应力腐蚀敏感性的影响主要体现在对阴极极化电位的影响,但是各种因素综合在一起导致应力腐蚀敏感性随温度变化的复杂性。更多还原

【Abstract】 Effects of temperature and applied potential stress corrosion behavior of X70 pipeline steel in Chengdu soil simulated solution were investigated by means of potentiodynamic scan,slow strain tensile( SSRT) and scanning electron microscopy observation,respectively. The results show that at different temperatures and different potentials,X70 pipeline steel shows different susceptibility to stress corrosion in the simulated soil solution and the effect of potential is obvious to stress corrosion susceptibility for X70 steel in simulated Chengdu soil solution.When the potential is- 450 m V,the mechanism of SCC is anodic dissolution; When the potential is- 850 m V,the anodic dissolution of the metal is inhibited; When the potential is- 1200 m V,X70 steel shows a strong stress corrosion susceptibility,and the mechanism of SCC is hydrogen embrittlement. The effect of temperature on stress corrosion susceptibility mainly reflects the influence on cathodic polarization potential,however the integration of different roles led to complexity of stress corrosion susceptibility varying with temperature.更多还原