反应等离子熔敷原位合成高铬铁基复合涂层高温抗氧化性
Oxidation resistance of reactive plasma cladding high-chromium iron-base composite coating
-
摘要: 利用前驱体碳化复合粉末制备技术,以蔗糖为碳的前驱体,制备了反应等离子熔敷Fe-Cr-C-W-Ni复合粉末;采用优化的反应等离子熔敷工艺,在调质C级钢(C≤0.35%)基材表面制备了以原位生成初生相(Cr,Fe)7C3为增强相,以γ固溶体与少量(Cr,Fe)7C3构成的共晶为基体的高铬铁基金属陶瓷复合涂层.应用EDS,SEM,XRD等研究了涂层的成分和组织结构.在900℃恒温氧化50 h的试验条件下测试了涂层的抗氧化性及氧化动力学曲线.结果表明,复合材料涂层及氧化膜的显微组织结构和相组成主要包括Cr2O3和Fe2O3,涂层具有较好抗氧化性能的原因是连续致密的氧化膜Cr2O3和Fe2O3阻挡了涂层被进一步氧化。Abstract: The sucrose was used as a carbonaceous precursor to prepare composite powders of Fe-Cr-C-W-Ni by the precursor carbonization-composition process.And the powders were fused to form a high-chromium iron-base coating on the surface of hardened and tempered grade C steel(C≤0.35%)with the optimum reactive plasma cladding process.SEM,XRD and EDS were employed to study compositions and microstructures of the coating.The oxidation resistance of the ceramal composite coating was investigated under the testing condition of 900℃ and 50 hours.The results indicate that the excellent oxidation resistance of the coating is mainly attributed to the relatively continuous oxide scales which mainly consist of Cr2O3 and Fe2O3,and the oxide scales can prevent the inner part of the composite coating from being further oxidized.