为提高马氏体不锈钢的耐蚀和耐磨性能,选择40Cr13不锈钢为基材、纯铌板为靶材,采用双辉等离子表面冶金技术在不锈钢表面制备合金化层.用SEM、GDOES、XRD等方法分析渗铌温度对铌合金层组织、成分、相组成、表面形貌及硬度的影响,并对渗层形成机制及表面硬化机理进行了研究.结果表明:在900~1 000℃形成的铌合金层组织均匀致密,合金层主要由Nb2C、Nb C、Fe2Nb、Cr2Nb及铌组成;合金层表面粗糙度随渗铌温度的提高而增加;合金层厚度随渗铌温度改变发生不同变化规律,950℃渗铌形成的渗层约13μm,900和1 000℃渗铌后合金层厚度均为7μm左右;不同温度渗铌后试样的表面硬度与基体相比均有较大幅度的提高,1 000℃渗铌后试样表面硬度高达约985 HV0.025,900℃渗铌后约758 HV0.025,而950℃渗铌后表面硬度最低,约698 HV0.025.
To improve the corrosion and wear resistances of martensitic stainless steel, an alloying layer was prepared on 40Cr13 stainless steel by double?glow plasma surface alloying technology. Effects of temperature on microstructure, chemical composition, phase structure, surface morphology and hardness of the Nb?alloyed layer are studied using SEM, GDOES, XRD. The formation mechanism of Nb?alloyed layer and its surface hardening mechanism were analyzed. The results show that the Nb?alloyed layers formed at 900~1 000℃ are continuous and compact, and mainly consistof Nb2 C, NbC, Fe2 Nb, Cr2 Nb and niobium. The alloyed steel exhibits a rough surface and different thickness of Nb?alloyed layer as alloying temperature increases. The alloyed layer, approximate 13μm in depth, is formed at 950℃ , and at temperature of 900℃and 1 000℃, the thickness of the alloyed layer is about 7μm. The surface hardness of the Nb?alloyed steel produced at 900, 950 and 1000 ℃ is about 758 HV0.025 , 698 HV0.025 and 985 HV0.025 , respectively, which greatly increase compared with the untreated 40Cr13 substrate.