Al含量对微束等离子熔覆Fe25合金组织和性能的影响

发布时间：2018-06-29 17:20

本文选题：微束等离子熔覆 + Fe合金覆层　；参考：《热加工工艺》2017年20期

【摘要】：采用微束等离子熔覆技术,在Q235钢基板上制备出一定Al含量的Fe25铁基合金覆层。采用光学显微镜(OM)、X射线衍射仪(XRD)、电子探针(EPMA)、显微硬度计、高温氧化试验研究了覆层的组织、硬度和高温抗氧化性能。结果表明,随着Al的加入(0~6wt%),Fe25合金覆层的凝固形态发生显著改变,基体相由奥氏体转化为铁素体,出现初生δ铁素体及碳硼化物相,最终覆层呈现铁素体和粒状贝氏体相结构。随着Al含量的增加,覆层显微硬度先升后降。4wt%Al的覆层2层平均硬度为618 HV0.2,比纯Fe25覆层提高286 HV0.2。随着Al含量的增加,由于Al原子的溶入和生成金属间化合物Fe_2AlCr、Fe_3Al,以及形成更致密的氧化膜,Fe25合金覆层的高温抗氧化性显著增强。
[Abstract]:Fe _ (25) Fe _ (25) alloy coating with certain Al content was prepared on Q235 steel substrate by microbeam plasma cladding technique. The microstructure, hardness and high temperature oxidation resistance of the coating were studied by optical microscope (OM) X-ray diffraction (XRD), electron probe microprobe (EPMA), microhardness tester and high temperature oxidation test. The results show that with the addition of Al (0 ~ 6 wt%), the solidification morphology of Fe _ (25) alloy cladding changed significantly, the matrix phase changed from austenite to ferrite, the primary 未 ferrite and carboboride phase appeared, and the final coating presented ferrite and granular bainite phase structure. With the increase of Al content, the microhardness of the coating increases first and then decreases. The average hardness of the two layers is 618 HV0.2, which is 286HV0.2 higher than that of pure Fe 25 coating. With the increase of Al content, the high temperature oxidation resistance of Fe _ 2AlCr-Fe _ 3AL alloy coating formed by Al atom melting and formation of Fe _ 2AlCr-Fe _ 3AL, as well as the formation of a denser oxide film, Fe _ (25) alloy coating, is obviously enhanced.
【作者单位】：武汉理工大学材料科学与工程学院;广东顺德亿港科技有限公司;
【基金】：国家自然科学基金项目(51475346) 佛山市顺德区经济和科技促进局技术创新专项资金项目(2012CX040)
【分类号】：TG174.4

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