| 摘要: |
| 为探索不同气氛对渗氮层组织和性能的影响，采用温度为 520 ℃，时间为 4 h、8 h 和 12 h，气氛分别为氨气或氨气+ 氮气混合气氛条件对 38CrMoAl 钢进行等离子体渗氮。利用金相显微镜、显微硬度计、X 射线衍射仪、扫描电镜和电化学工作站，对改性层的截面显微组织、显微硬度、渗层脆性、相组成、形貌成分以及耐蚀性等进行表征。氨气渗氮后，渗层厚度平均为 249.4 μm，平均增质量 2.30 mg / cm2 ，4 h 后硬度达到最大 990.5 HV0.05 氨氮混合气氛渗氮后，渗层厚度平均为 294.8 μm， 平均增质量 2.39 mg / cm2 ，4 h 后硬度达到最大 1 000.2 HV0.05。氨气渗氮层主要相为 γ'-Fe4N，次要相为 ε-Fe2-3N；氨氮混合气氛渗氮层中主要相变为 ε-Fe2-3N，次要相为 γ'-Fe4N。氨氮混合气氛渗氮 4 h 后，改性层腐蚀速率最小(108.05 μm / a)，电流密度下降到最低(9.19 μA / cm2 )。 |
| 关键词: 38CrMoAl 钢 等离子体渗氮 显微硬度 耐蚀性 改性层 |
| DOI：10.11933/j.issn.1007-9289.20210425003 |
| 分类号:TG156 |
| 基金项目:国家自然科学基金(51401113)、黑龙江省自然科学基金(E2016069)、黑龙江省重点研发计划指导类(GZ20210034)和黑龙江省聚合物基复合材料重点实验室开放课题(CLKFKT2021B7)资助项目 |
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| Characterization of Plasma Nitrided Layer at Different Atmosphere Conditions on 38CrMoAl Steel at 520 ℃ |
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Liu Dongjing1, You Yuan1,2, Yan Mufu2, Chen Hongtao3, Wang Chaohui1, Li Rui1, Hong Lin1, Han Tingjie1
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1.School of Materials Science and Engineering, Qiqihar University, Qiqihar 161006 , China;2.School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 , China;3.School of Materials Science and Engineering, Harbin University of Science and Technology, Harbin 150040 , China
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| Abstract: |
| In order to explore the influence of different atmospheres on the microstructures and properties of plasma nitrided layers, the nitrided treatments are carried out on 38CrMoAl steel at 520 ℃ for 4 h, 8 h and 12 h in different atmosphere (NH3 or NH3 + N2). The modified layers are characterized by optical microscope (OM), microhardness tester, X-ray diffraction (XRD), scanning electron microscope (SEM), electrochemical workstation. After nitrided in NH3, the average thickness of the modified layer is 249.4 μm, the average mass gain is 2.30 mg / cm2 , the hardness reaches the maximum (990.5 HV0.05) after 4 h, the main phase is γ'-Fe4N, the minor phase is ε-Fe2-3N. After nitriding in NH3 + N2, the average thickness of the nitriding layer is 294.8 μm, the average mass gain is 2.39 mg / cm2 , the hardness reaches the maximum (1 000.2 HV0.05) after 4h, the main phase is ε-Fe2-3N, and the minor phase is γ'-Fe4N. After nitriding in NH3 + N2 for 4, the corrosion rate of the nitrided layer is the smallest (108.05 μm / a), and the current density decreases to the lowest (0.919 × 10?5 A / cm2 ) 9.19 μA / cm2 . |
| Key words: 38CrMoAl steel plasma nitriding microhardness corrosion resistance modified layer |
