共查询到18条相似文献,搜索用时 156 毫秒
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用自制的恒位移加载台,在透射电镜中原位观察310奥氏体不锈钢在纯水中局部溶解前后裂尖位错组态的变化以及微裂纹的形核和扩展。结果表明,310奥氏体在室温纯水中局部阳极溶解促进位错发射,增殖和运动,在低应力下,纳米级微裂纹在无位错区中连续或不连续形核,由于介质的作用,纳米级微裂纹并不钝化成空洞或缺口,而是理解扩展。 相似文献
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氢对310不锈钢钝化膜的影响 总被引:1,自引:1,他引:0
采用电化学和STM方法研究了氢对310不锈钢阳极极化过程,钝化膜形成过程和表面形貌特征以及膜耐点蚀性能的影响,并进行了相应的理论分析。研究表明:氢会降低不锈钢的自腐蚀电位,缩短钝化区域并使其向低电位方向偏移;降低反应电阻,增大钝化电流工,降低膜在纳米尺度上的结晶度和耐点蚀性能。 相似文献
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HUANG Yanliang CAO Chu''''nan LIN Haichao LU Ming Corrosion Science Laboratory Institute of Corrosion Protection of Metals Academia Sinica Shenyang China Ph D student Institute of Corrosion Protection of Metals Academia Sinica Shenyang China 《金属学报(英文版)》1993,6(12):416-420
It is verified that stainless steel AISI 321 is in the active anodic dissolution state in 0.5mol/L HCll+0.5 mol/L NaCl solution at 55℃.The SCC of the steel in the solution cannot be reasonably explained by passive film rupture-nepasivation theory and by hydrogenembrittlement theory.There are evidences that the fracture stress at the tip of the cracksis reduced by anodic dissolution due to its role in relieving strain hardening layer at cracktip. 相似文献
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H. Yanliang 《工业材料与腐蚀》2004,55(2):102-105
In corrosion medium, metals can deform under tensile stress and form a new active surface with the anodic dissolution of the metals being accelerated. At the same time, the anodic dissolution may accelerate the deformation of the metals. The synergy can lead to crack nucleation and development and shorten the service life of the component. Austenitic stainless steel in acidic chloride solution was in active dissolution condition when stress corrosion cracking (SCC) occurred. It is reasonable to assume that the anodic dissolution play an important role, so it's necessary to study the synergy between anodic dissolution and deformation of austenitic stainless steels. The synergy between deformation and anodic dissolution of AISI 321 austenitic stainless steel in an acidic chloride solution was studied in this paper. The corrosion rate of the steel increased remarkably due to the deformation‐accelerated anodic and cathodic processes. The creep rate was increased while the yield strength was reduced by anodic dissolution. The analysis by thermal activation theory of deformation showed a linear relationship between the logarithm of creep rate and the logarithm of anodic current. Besides, the reciprocal of yield strength was also linearly dependent on the logarithm of anodic current. The theoretical deductions were in good agreement with experimental results. 相似文献
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稳定奥氏体不锈钢氢渗透的研究 总被引:2,自引:0,他引:2
本文用电化学氢渗透法,研究了钝化膜、极化电位及介质中pH值对氢在稳定奥氏体不锈钢中渗透行为的影响。测定了氢在310奥氏体不锈钢中25℃时的扩散系数为(1.2±0.1)×10~(-8)cm~2/sec;估算了氢在钝化膜中的扩系散数约为10~(-8)cm~2/sec数量级。随着介质中pH值的降低,氢渗透的饱和电流增加。不仅阴极极化可增加氢渗透的饱和电流;当电位超过点蚀击穿电位后,阳极极化也可增加氢渗透的饱和电流。充氢后试样在0.1NH_2SO_4溶液中的阳极极化曲线显著地向右移动;充氢后的固溶处理试祥,也具有明显的晶间腐蚀倾向。 相似文献
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弹、塑性应变对奥氏体不锈钢AISI321电化学行为的影响 总被引:1,自引:0,他引:1
探讨了弹、塑性应变对奥氏体不锈钢电化学行为的影
响,从热力学判据和电化学参数的关系出发,分析了不锈钢的应变电化学行为.结果表明,静态无载荷试样和动态慢拉伸试样的电化学行为明显不同.弹性应变只影响金属阳极溶解过程,而不影响阴极过程.形变强化和位错塞积群的形成对金属的力学-化学活性起着决定性的作用. 相似文献
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利用扫描电镜、能谱分析和X射线衍射研究质子辐照前后的奥氏体不锈钢AL-6XN在高温高压水中的腐蚀行为。结果表明,未辐照的样品在高温高压水中生成了完整的氧化膜,样品增重随着浸泡时间的增加而增加,温度越高腐蚀增重越显著。经过质子辐照后的材料在290℃/10 MPa水中氧化膜发生了严重的溶解,浸泡后样品出现了失重,在550℃/25 MPa超临界水中外层氧化膜发生了剥落,且浸泡时间越长氧化膜剥落越严重。质子辐照不影响氧化膜的元素组成和相结构,同时建议了质子辐照后奥氏体不锈钢在高温水中氧化膜剥落的模型。 相似文献
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采用低耗能激光焊新工艺制造水龙头薄壳,替代传统高污染、高耗能的整体铸造工艺,对304、310 s不锈钢激光焊接头进行沸腾硫酸-硫酸铁及室温浸蚀对比腐蚀研究.在设定的腐蚀时间内,采用“原位观察”腐蚀过程焊缝及熔合区微观组织变化.结果表明,310 s比304耐腐蚀性更好,随腐蚀时间加长,接头熔合区晶粒晶界未明显加宽,焊缝断口微观特征主要为韧窝,证明其未发生晶间腐蚀.焊缝金属成分分析表明焊缝中心晶粒与母材相近,腐蚀沟Cr元素降至20.81%高于12%,保证其耐腐蚀性能. 相似文献