GL渗铝钢管渗铝层的显微硬度及相组成

采用光镜、显微硬度计、扫描电镜（ＳＥＭ）、电子探针（ＥＰＭＡ）和Ｘ－射线衍射等试验方法，对感应料浆法（ＧＬ）渗铝钢管Ｆｅ—Ａｌ合金渗层的显微硬度和相组成特征进行研究。结果表明，ＧＬ渗铝钢管渗铝层显微硬度由表及里为６００～３２０ＨＭ，渗铝层由α─Ｆｅ（Ａｌ）固溶体、Ｆｅ３Ａｌ和ＦｅＡｌ相构成，不存在含铝较高的ＦｅＡｌ２、Ｆｅ２Ａｌ５和ＦｅＡｌ３等脆性相，改善了渗铝钢的抗变形能力和焊接性能。

MICROHARDNESS AND PHASE COMPOSITION OF ALUMINIZATION LAYER OF GL ALUMINIZED STEEL TUBE

With optical microscope,micro- hardometer, scanning electron microscope(SEM),EPMA and X-ray diffraction method,investigations on the microhardness and the phase composition char acteristics of the Fe-Al alloyed layer of the GL aluminized(induction slurry process)steel tube were made.The result shows that the microhardness of the said aluminized layer ranges inward from 600 HM to 320 HM,while the layer itself is composed by α-Fe(Al) solid solution, Fe3Al and FeAl,and that no high Al containing brittle phases like those of FeAl2, Fe2Al5, and FeAl3 are found,which means better deformation resistance and weldability of the aluminized steel.