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为从本质上揭示高温碱金属盐与载荷混合作用环境下合金的腐蚀机理、蠕变变形机理和组织变化,利用微观形貌检测及产物成分分析法,研究高温碱金属氯盐环境下12Cr1Mo V合金在不同外加载荷和反应时间下的压缩蠕变行为。结果表明:压应力对12Cr1Mo V的热腐蚀有促进作用;随载荷的增大,截面腐蚀层厚度增加,产物更加疏松多孔且更易脱落;同时,晶界上析出的M23C6呈不连续状粗化分布,成为弱化基体抗压强度的重要因素之一;碱金属氯盐在高温环境中以沿晶侵蚀为主,并对部分铁素体和球化现象较严重的珠光体晶粒结构造成破坏;在压缩载荷长时间的作用下,晶界裂纹沿加载应力方向扩展产生层断裂现象;而被侵蚀的晶粒易引发应力集中并扩大断层裂纹的间隙,进而加速材料内部的蠕变变形。
In order to reveal the corrosion mechanism, creep deformation mechanism and microstructure changes of alloy under the condition of high temperature alkali metal salt mixed with load, the microstructure and composition of the alloy were studied to study the properties of 12Cr1Mo V alloy Compressive creep behavior under different applied loads and reaction time. The results show that the compressive stress can promote the hot corrosion of 12Cr1Mo V. With the increase of load, the thickness of cross-section corrosion layer increases, the product is more porous and more easily peeled off. Meanwhile, M23C6 precipitated on the grain boundary presents discontinuous coarse distribution , Which is one of the important factors to weaken the compressive strength of the matrix. Chloride salts of alkali metal are mainly eroded along the crystal at high temperature, and cause damage to the crystal structure of the pearlite which is partly ferrite and spheroidization. Under the action of compressive load for a long time, the grain boundary crack expands along the direction of loading stress to produce layer fracture phenomenon. However, the eroded crystal grains can easily induce stress concentration and expand the gap of the fracture, which accelerates the creep deformation in the material.