钨极氩弧熔覆原位自生铁基复合涂层组织与性能

发布时间：2018-04-13 01:38

本文选题：氩弧熔覆 + 原位合成　；参考：《表面技术》2017年07期

【摘要】：目的以钨极氩弧作为热源,在Q235钢表面原位自生铁基复合涂层。方法以铁粉、铁基合金粉(G302)、B4C粉末作为预置合金粉,设置两种粉末质量比Fe:B4C=15:1(记为S1)、G302:B4C=8:1(记为S2),在Q235钢表面原位合成铁基复合涂层。对涂层进行一系列组织性能表征,利用扫描电镜(SEM)分析涂层的显微组织,采用X射线衍射仪(XRD)分析涂层的物相组成,利用MHV-2000型数字式显微硬度计测量熔覆试样显微硬度的变化。结果在试样S1和S2中,涂层与基体呈现良好的冶金结合,在结合界面处没有气孔、裂纹等缺陷。通过XRD分析可知,预置合金粉末发生了化学反应且反应比较充分,没有B4C剩余。试样S1中的增强相主要由Fe_2B、Fe_7C3、Fe_3C组成,试样S2中的增强相主要由Cr-Fe、(Cr,Fe)7C3、(Fe,Cr)2B组成。试样S1中的硼化物及碳化物呈不连续网状分布;试样S2中的网状结构减弱,出现了块状和短棒状结构。试样S1和S2基体至涂层的显微硬度呈梯度变化,且涂层的显微硬度明显比基体高,S2中涂层的显微硬度达到1200HV0.1,约是基体硬度的6倍。结论利用上述预制合金粉可以原位合成铁基复合涂层。随着硼元素含量的提高以及Cr元素的加入,有助于改善硼化物形态,使其由网状结构向块状转变。原位生成复合陶瓷增强相均匀分布在铁基体上,涂层硬度显著提高。
[Abstract]:Aim to use argon tungsten arc as heat source and in situ autogenous iron based composite coating on Q235 steel surface.Methods using iron powder and iron base alloy powder G302OB4C as preset alloy powder, two kinds of Fe-based composite coating were prepared on Q235 steel surface by mass ratio of Fe: B _ 4C _ (15): 1 (S _ (1)) G302B _ (4C) C ~ (8): 1 (S _ (2)).A series of microstructure and properties of the coating were characterized. The microstructure of the coating was analyzed by scanning electron microscope (SEM), the phase composition of the coating was analyzed by X-ray diffractometer, and the microhardness of the cladding sample was measured by MHV-2000 digital microhardness meter.Results in S _ 1 and S _ 2 samples, the coating had good metallurgical bonding with the substrate, and there were no defects such as pores and cracks at the bonding interface.According to XRD analysis, there is a chemical reaction in the prepared alloy powder and the reaction is quite sufficient, and there is no B _ 4C residue.The reinforcement phase in specimen S1 is mainly composed of FeSh 2BnFe7C3C + Fe3C, and the reinforcement phase in specimen S2 is mainly composed of Cr-FeFe7C3C3 + FeN2B.The distribution of boride and carbides in S _ 1 is discontinuous, while the reticular structure in S _ 2 is weakened, and there are block and short bar structures.The microhardness from S1 and S2 substrates to the coating varies in gradient, and the microhardness of the coating is obviously higher than that of the coating in S _ 2, which is about 6 times of that of the substrate.Conclusion the Fe-based composite coating can be synthesized in situ by using the prefabricated alloy powder mentioned above.With the increase of the content of boron and the addition of Cr, the morphology of boride can be improved and the shape of boride can be changed from reticular structure to block shape.The in-situ composite ceramic reinforced phase distributed uniformly on the iron substrate, and the hardness of the coating increased significantly.
【作者单位】：河南科技大学材料科学与工程学院;有色金属共性技术河南省协同创新中心;洛阳金鹭硬质合金有限公司;
【基金】：国家自然科学基金(U1604132) 河南省科技攻关计划项目(172102210259)~~
【分类号】：TG174.4

【相似文献】