碳含量对热等静压态FGH96合金碳化物的影响

Effect of Carbon on Carbides in HIPed FGH96 Alloy

对不同碳含量的FGH96成型合金中碳化物进行了研究,并对合金原始粉末表面成分偏析进行了测定,以深入探讨碳含量对合金中碳化物的影响。结果表明:FGH96合金中碳含量的增加,提高了原始粉末表面碳含量和富Ti层厚度;HIP(热等静压)态FGH96中碳化物主要为富Ti和Nb的MC,随着碳含量升高,合金中分布在原始粉末颗粒边界(previous particle boundary,PPB)上和PPB以外区域的碳化物含量均逐渐升高,而非PPB碳化物含量上升的幅度相对较大;合金中碳含量越高,PPB碳化物中强碳化物形成元素的含量越低,非PPB碳化物的成分不受合金碳含量的影响;碳的加入促进了PPB碳化物的粗化,并扩展了其尺寸分布的范围;合金中碳含量越高,PPB碳化物的平均自由程越小,合金在室温下的断面收缩率越低。

The carbides of HIPed FGH96 alloys with different carbon contents were studied. The surface composition segregation of FGH96 initial powders was also investigated in order to explore the effect of carbon content on the carbides of the HIPed alloys. The results show that the increase of carbon addition in FGH96 alloy enhances the Ti-rich area and the carbon concentration of the initial powder surface. The carbides in HIPed FGH96 are mainly MC which is rich in Ti and Nb. The volume percentages of PPB carbides and non-PPB carbides increase with rising of carbon addition. But the increasement of the later is lager. With increasing of carbon content, the amount of strong carbides-forming elements in PPB carbides decreases while that in non-PPB carbides does not change much. The carbon addition not only induces the coarsening of PPB carbides, but also enlarges the range of PPB carbides size distribution. The higher the content of carbon in the alloy is, the shorter the average free path of PPB carbides is, the lower the reduction of area for the alloy at room temperature is.