Compositional Change of Refractory Elements in Solution during Aging in High Cr Heat Resistant Ferritic Steels
Compositional Change of Refractory Elements in Solution during Aging in High Cr Heat Resistant Ferritic Steels
复制标题
高铬耐热铁素体钢时效过程中固溶难熔元素的成分变化
DOI：
10.2355/isijinternational.42.1591
复制
发表时间：
2002
影响因子：
1.8
通讯作者：
T. Ishiguro
中科院分区：
文献类型：
--
作者：
Y. Murata;K. Kawamura;M. Kamiya;M. Morinaga;R. Hashizume;K. Miki;T. Azuma;T. Ishiguro
在高铬耐热铁素体钢中加入硼和难熔元素钼、钨，可提高钢的蠕变强度。人们已经接受耐火元素的改善主要源于钢的固溶硬化。另一方面，在那些含有相对大量耐火元素的钢中，由于金属间化合物的沉淀硬化，存在金属间化合物的细小共格沉淀物，从而改善了蠕变强度。然而，在含有过量耐火元素，特别是W的钢中，已知长时间的蠕变强度变得低于从短时间的蠕变强度推断的值。最近，已经发现Re是用于改善高Cr铁素体钢的长期蠕变强度的有效元素。这与W对铁素体钢的影响相反。如上所述，当考虑高Cr铁素体钢的蠕变强度时，研究难熔元素在基体中的固溶度极限是重要的。这通常是通过基于钢的化学成分以及提取残渣的重量的热力学计算间接获得的，因此在计算值中不可避免地包括一些误差。然后，在本研究中采用了直接分析方法，而不是这种间接的方法。在该方法中，溶解在基体中的难熔元素的量直接通过电解液的ICP发射光谱化学分析来分析，所述电解液是通过电解钢中的基体相而制备的，如下文所述。
The improvement in the creep strength has been achieved by the addition of boron as well as refractory elements, Mo and W in high Cr heat resistant ferritic steels. It has been accepted that the improvement by the refractory elements originates mainly in the solid-solution hardening of steels. In those steels containing a comparatively large amount of the refractory elements, on the other hand, the creep strength is improved by the presence of fine coherent precipitates of intermatallic compounds due to the precipitation hardening in them. However, in the steels containing an excess amount of refractory elements, in particular, W, it is known that the creep strength in a long time becomes lower than the values extrapolated from the creep strength in a short-time. Recently, it has been found that Re is an effective element for improving a long-time creep-strength of high Cr ferritic steels. This is in contrast to the effect of W on the ferritic steels. As mentioned above, it is important to investigate the solid solubility limit of refractory elements in the matrix when considering the creep strength of high Cr ferritic steels. This is usually obtained indirectly by the thermodynamic calculation based on the chemical composition as well as the weight of the extracted residue from the steels, so that some errors are included inevitably in the calculated values. Then instead of such an indirect method, a direct analyzing method is employed in this study. In this method, the amount of refractory elements dissolved in the matrix is analyzed directly by means of the ICP emission spectrochemical analysis of the electrolyte which is prepared by electrolyzing the matrix phase in the steel, as explained later.