316L不锈钢表面沉积CrCN薄膜的结构及性能研究

利用多弧离子镀技术在316L不锈钢和单晶硅上沉积CrCN薄膜,通过X射线衍射仪(XRD)、扫描电镜(SEM)、X射线光电子能谱仪(XPS)、纳米压痕仪、273A电化学工作站和多功能摩擦磨损试验机等对316L不锈钢及CrCN薄膜的微观结构、力学性能、耐腐蚀性能和摩擦学性能进行表征.结果表明:在316L不锈钢上沉积CrCN薄膜后,硬度从4 GPa提高到22 GPa,H/E和H3/E2分别从0.022和0.002 GPa提高到0.071和0.11 GPa;阳极腐蚀电位从-0.21 V上升到-0.19 V;在大气,去离子水,海水环境下的摩擦系数及磨损率均显著降低,表现出较优异的综合性能.     

Effects of Nitrogen Flow Rate on the Performances of Cathodic Arc Deposited TiN Films on 316L Stainless Steels as Bipolar Plates for the Proton-Exchange Membrane Fuel Cell

The corrosion resistance, interfacial contact resistance (ICR), and hydrophobicity of cathodic arc deposited TiN films on 316L stainless steels at different nitrogen flow rates as bipolar plates (BPs) for the proton-exchange membrane fuel cell (PEMFC) are investigated. It is shown in the results that the TiN-coated 316L stainless steel prepared at a moderate nitrogen flow rate (250 sccm) exhibits a low stable corrosion current density of 6.5 × 10⁻⁸ A cm⁻² in the simulated corrosive cathode environment of PEMFC, and a low ICR of 8.94 mΩ cm⁻² at a pressure of 1.38 MPa after corrosion, meanwhile presents a good hydrophobicity before and after corrosion. These results are discussed by considering the probable effects of the nitrogen flow rate on the substrate/coating system based on the microstructural characterization of the substrate/coating interface and the coating, which shows that the interdiffusion will be started in the deposition process and a moderate nitrogen flow rate during the coating process will promote to the broadening of interface region and lead to the formation of a robust and high-quality coating with fewer defects that can effectively improve the performances of the 316L stainless steel substrate as the BP for PEMFC.     

电沉积RE-Ni-W-P-SiC复合镀层的耐蚀性研究

本文提供了RE-Ni-W-P-SiC复合材料在不同浓度的H2S04、nCI、H3PO4和FeCl2溶液中的腐蚀速率。试验结果表明该复合材料比不锈钢316L有更好的耐蚀性。     

热喷涂 WC-MoB-Co 金属陶瓷涂层的耐腐蚀性能研究

本文采用团聚烧结法制备了 WC-MoB-Co 金属陶瓷喷涂粉末, 使用超音速火焰喷涂技术在 316L 不锈钢基 材上制备了 WC-MoB-Co 涂层; 采用 SEM、 XRD 表征了 WC-MoB-Co 粉末和腐蚀前后涂层的微观形貌及物相组成; 测试了 WC-MoB-Co 涂层耐熔融锌铝腐蚀性能。 研究结果表明, 制备的 WC-MoB-Co 金属陶瓷复合粉末粒度集中、 流动性好、 松装密度高; WC-MoB-Co 涂层结合强度高、 孔隙率低; WC-MoB-Co 涂层具有良好的耐腐蚀性能, 随着腐蚀时间的延长, 涂层中的 WC 颗粒逐渐参与反应。     

The Effects of Ce on Hot Corrosion of Iron-based Alloys

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Graphite-polypyrrole coated 316L stainless steel as bipolar plates for proton exchange membrane fuel cells

316L stainless steel (SS 316L)is quite attractive as bipolar plates in proton exchange membrane fuel cells (PEMFC).In this study,graphite-polypyrrole was coated on SS 316L by the method of cyclic voltammetry.The surface morphology and chemical composition of the graphite-polypyrrole composite coating were investigated by scanning electron microscopy (SEM)and X-ray photoelectron spectroscopy (XPS).A simulated working environment of PEMFC was applied for testing the corrosion properties of graphite-polypyrrole coated SS 316L.The current densities in the simulated PEMFC anode and cathode conditions are around 3×10-9 and 9×10-5 A.cm-2,respectively.In addition,the interfacial contact resistance (ICR)was also investigated.The ICR value of graphite-polypyrrole coated SS 316L is much lower than that of bare SS 316L.Therefore,graphite-polypyrrole coated SS 316L indicates a great potential for the application in PEMFC.     

Intermetallic diffusion coatings for enhanced hot-salt oxidation resistance of nitrogen-containing austenitic stainless steels

This article presents the preparation, characterization, and hot-salt oxidation behavior of nitrogen-containing type 316L stainless steel (SS), surface modified with intermetallic coatings. Three different types of intermetallic coating systems, containing aluminum, titanium, and titanium/aluminum multilayers, were formed by diffusion annealing of type 316L austenitic SS containing 0.015, 0.1, 0.2, and 0.56 pct nitrogen. Analysis by using X-ray diffraction (XRD), scanning electron microscopy (SEM), and secondary ion mass spectroscopy (SIMS) confirmed the formation of various intermetallic phases such as AIN, Al₁₃Fe₄, FeAl₂, FeTi, Ti₂N, and Ti₃Al in the coatings. Hot salt oxidation behavior of the uncoated and surface-modified stainless steels was assessed by periodic monitoring of the weight changes of NaCl salt-applied alloys kept in an air furnace at 1023 K up to 250 hours. The oxide scales formed were examined by XRD and stereomicroscopy. Among the various surface modifications investigated in the present study, the results indicate that the titanium-modified alloys show the best hot-salt oxidation resistance with the formation of an adherent, protective, thin, and continuous oxide layer. Among the four N-containing alloys investigated, the titanium and Ti/Al multilayer modified 0.56 pct N alloy showed the best hot-salt oxidation resistance as compared to uncoated alloys. The slower corrosion kinetics and adherent scale morphology indicate that the surface-modified titanium intermetallic coatings could provide high-temperature service applications up to 1073 K, particularly in chloride containing atmospheres, for austenitic stainless steels.     

TMCP工艺轧制桥梁用不锈钢复合板的组织与性能

为了获得桥梁用不锈钢复合板良好的综合性能,采用控轧控冷(thermal mechanical control process,简称TMCP)工艺轧制了桥梁用不锈钢复合板316L+Q370qD,利用金相、扫描、拉伸、冲击、弯曲、剪切和晶间腐蚀等手段研究了该复合板的组织与性能。结果表明,316L+Q370qD桥梁用不锈钢复合板的界面实现了完全冶金结合,未发现孔洞、裂纹等缺陷以及大颗粒的析出物及氧化物夹杂等;复合板的屈服强度为421~446MPa,伸长率为24.0%~28.0%,-20℃纵向冲击吸收能量平均值为200J,180°内、外弯曲合格,平均剪切强度为412 MPa,复合板的各项力学性能均满足GB/T 8165—2008《不锈钢复合钢板和钢带》标准要求。按照GB/T 4334—2008方法 E进行晶间腐蚀试验,复层不锈钢316L未出现晶间腐蚀现象,具有良好的耐晶间腐蚀性能。     

甲酸浓度对316L不锈钢腐蚀钝化?活化转变行为的影响

为深入认识316L不锈钢在甲酸溶液中的钝化-活化转变行为,在90 ℃、质量分数为0~30%的甲酸溶液中对316L不锈钢进行全浸试验和阳极极化曲线测试。研究了甲酸质量分数对316L不锈钢腐蚀速率、腐蚀形貌、开路电位、初始钝化电位、临界电流密度、钝化电流密度和钝化膜破裂电位的影响规律,分析了H+ 和HCOO? 含量对活化区、过渡区和钝化区阳极反应的影响机制。结果表明,316L不锈钢在甲酸溶液中发生非均匀的全面腐蚀。当甲酸质量分数达到30%、腐蚀速率为1.2×10?3 mm·a?1时,316L不锈钢就具有明显的钝化?活化转变。随着甲酸质量分数增加,316L不锈钢的初始钝化电位正移、临界电流密度增大、钝化电流密度增大、钝化膜破裂电位负移。甲酸溶液中H+ 和HCOO? 含量的增加,会加速316L不锈钢活性溶解,抑制钝化膜生长,促进钝化-活化转变。      

Powder metallurgical production of 316L stainless steel/niobium composites for Proton Exchange membrane electrolysis cells

In this study, a composite made of a porous stainless steel (SS) 316L substrate coated with Nb was investigated as a novel porous transport layer (PTL) for proton exchange membrane electrolysis cells (PEMECs). The fabrication of such SS316L/Nb composites using scalable and automatable powder metallurgical techniques as tape casting, screen-printing and field assisted sintering technology/spark plasma sintering (FAST/SPS) was described. Sintering behaviour and the interdiffusion at the SS316L/Nb interface were investigated. Powder metallurgical techniques such as screen-printing are the preferred method to achieve a porous Nb coating, while FAST/SPS is the preferred method for a better control of the SS316L/Nb interface by lowered interdiffusion. First electrochemical performance tests with SS316L/Nb composites demonstrate they have potential to replace the state-of-the-art titanium-based PTLs. The use of SS316L is expected to decrease manufacturing costs of PTLs, while the addition of niobium layer, due to its excellent corrosion resistance in acid environment, aims to improve PEMECs lifetime and performance.     

冷喷涂TC4合金涂层性能研究

冷喷涂技术由于处理温度低,在制备易氧化和热敏感材料方面有很大的优势,特别是制备钛合金涂层能保持钛不被氧化发蓝。不锈钢受氯离子影响在海洋环境中点蚀风险极大,影响了其在海洋环境的应用,钛合金涂层则可以有效的解决这个问题。本文采用冷喷涂方法在不同工艺参数下在304不锈钢表面制备了Ti-6Al-4V(TC4)合金涂层,利用微观方法观察了涂层的形貌、组织结构,并利用电化学方法研究了涂层的腐蚀电化学特征。研究结果表明,冷喷涂制备的TC4合金涂层表观形貌较为粗糙,且内部组织结构不够紧密,氧化程度没有明显增加,但是腐蚀电化学行为与TC4基体相当,是理想的表面处理技术,作为涂层材料可大大提升不锈钢在海洋环境下的耐点蚀性能,具有广阔的应用前景。     

Research progress of austenitic stainless steel made by metal additive manufacturing

Compared with the parts prepared by conventional methods, the parts formed by metal additive manufacturing (MAM) technology are prone to have non equilibrium and sub micro cellular structures, which show more excellent performance. Especially, the 316L stainless steel formed by laser powder bed melting technology has high yield strength, good elongation, and excellent corrosion resistance. Aiming at the superfast thermal cycle, complex metallurgical reactions, intense non equilibrium solidification, and particular thermal history of MAM technologies, the current advances in the related fields of laser powder bed fusion 316L (L PBF 316L) austenitic stainless steel were systematically reviewed. The mechanical properties and corrosion mechanism of L PBF 316L and its influencing factors including microstructural features evolution and corresponding regulation were discussed. All importantly, the strengthening and toughening mechanisms of 316L deformation were thoroughly revealed. Finally, a brief prospect on the future research direction of additive manufacturing austenitic stainless steel was provided.     

不锈钢在高温高压釜乙酸溶液中耐腐蚀性能研究

在试验室中模拟不锈钢所处的高温高压生产环境,对两种牌号不锈钢在同种乙酸介质中的耐腐蚀性能进行对比实验研究,并且对同种不锈钢试样在不同方法制备的乙酸介质中的耐腐蚀性能进行对比研究。试验结果显示,送样316L不锈钢的耐腐蚀性能较00Cr17Ni14Mo2不锈钢的耐腐蚀性能差;316L不锈钢在乙醇制乙酸中的耐腐蚀性能低于在乙烯制乙酸中的耐腐蚀性能。上述试验为某化工厂生产设备的选材以及生产介质的选择提供了相应依据和参考。     

Stellite12 和 Stellite20 涂层的耐磨性和耐腐蚀性能对比研究

利用超音速火焰喷涂技术 (High-velocity-oxy-fuel, HVOF) 在 F316 不锈钢表面制备 Stellite 12 和 Stellite 20 两种钴基合金涂层, 对比研究了涂层的摩擦磨损性能以及在不同浓度硫酸溶液中耐腐蚀性。 采用 HT2101 销盘磨 损试验仪, 进行了摩擦磨损试验。 利用电子探针仪 (EPMA) 观察涂层的微观组织形貌, WDS 波谱仪分析涂层微 区成分。 采用三电极体系在 CHI660C 电化学工作站上测试 Stellite12 和 Stellite20 涂层在不同浓度硫酸溶液中的极 化曲线, 并与 F316 不锈钢进行对比。 结果表明, HVOF 工艺制备的 Stellite12 和 Stellite20 涂层均匀致密, 无裂纹 等缺陷, 显微硬度分别为 750 HV0.3 和 1000 HV0.3; Stellite 12、 Stellite 20 涂层的摩擦系数约 0.55~0.6。 磨损机理 主要为磨粒磨损, 伴随一定的粘着磨损。 Stellite 12 的磨损量为 Stellite 20 的两倍。 在室温条件下, 两种涂层在质 量分数 20 % 和 50 % 硫酸溶液中腐蚀电位均低于 F 316 的腐蚀电位, F 316 具有较好的耐腐蚀性; 在 80% 硫酸溶 液中, 这两种涂层的腐蚀电位均高于 F 316 的腐蚀腐蚀电位, F 316 不锈钢耐蚀性相对较差。     

金属粉床增材制造奥氏体不锈钢的研究进展

摘要：金属增材制造技术成形奥氏体不锈钢易出现与传统制备方法完全不同的非平衡亚稳微观组织,表现出独特的性能,其中激光增材制造的316L不锈钢,兼具高屈服强度、良好的伸长率以及优异的耐腐蚀性能。系统综述了近年来国内外激光增材制造316L不锈钢的研究进展,针对其高冷却速率、微熔池冶金、强非平衡凝固和复杂热履历成形条件,阐述其微观组织结构的形成机制和调控方法,以及对力学性能和腐蚀行为的影响规律,重点分析了激光增材制造316L奥氏体不锈钢的强韧化机制,最后展望增材制造奥氏体不锈钢的未来研究方向。     

表面处理对海洋工程用316L不锈钢耐点蚀性能的影响

316L不锈钢为常用的耐蚀合金材料,然而其在海洋大气环境服役时易遭受点腐蚀而发生失效。通过点腐蚀速率、临界点蚀温度、点蚀电位、极化曲线测试等评价方法,对经过不同表面处理(光亮退火、抛光、酸洗钝化)后的316L不锈钢的耐点蚀性能进行测试分析。结果表明,不同表面处理对316L不锈钢的临界点蚀温度影响不大,但会使点腐蚀速率、点蚀电位有所差异;在测试条件下,抛光及酸洗钝化均可有效提高316L不锈钢的耐点蚀性能,其中酸洗钝化态的耐点蚀性能最好,因此建议对海洋工程用316L不锈钢产品在使用前进行酸洗钝化处理。     

Effect of heating mode and electrochemical response on austenitic and ferritic stainless steels

Abstract

Powder metallurgical (P/M) processing has the main advantage of making near net shape products. Nowadays, in automobile industries, stainless steels have become the most promising material owing to their good corrosion resistance. In the current study, 316L and 434L stainless steel powders were sintered using microwave and conventional methods through powder metallurgy route. The effects of sintering modes on the microstructure, mechanical properties and corrosion responses of 316L and 434L stainless steel composites are investigated in detail. The results showed that the sample prepared through microwave sintering route exhibited significantly superior densification, higher hardness and better corrosion resistance as compared to the conventionally processed counterpart. On the whole, 316L composites showed better corrosion resistance than 434L stainless steels.     

445M铁素体不锈钢缝隙腐蚀性能的研究

研究了445M铁素体不锈钢(%:0.004～0.005C、22.24～22.29Cr、1.10～1.65Mo、0.015～0.016P、0.003～0.004S、0.012～0.016N、0.22～0.38Ti)和316L奥氏体不锈钢(%:0.022C、16.80Cr、10.19Ni、2.02Mo、0.025P、0.001S、0.046N)在40～60℃氯离子浓度(250～5 000)×10^-6的氯化钠溶液的缝隙腐蚀性能。结果表明,445M铁素体不锈钢的耐缝隙腐蚀性能优于316L奥氏体不锈钢;当445M钢中的Mo含量由1.10%提高至1.65%时,钢的耐缝隙腐蚀性能明显提高,表明点蚀当量Cr+3.3Mo是衡量不锈钢耐点蚀和耐缝隙腐蚀的重要指标。     

Effect of Additive Cu-10Sn on Sintering Behavior and Wear Resistance of 316L Stainless Steel

 Austenitic 316L stainless steel has good corrosion resistance; however, the relative softness often limits its application. Severe adhesive wear often occurs between the 316L stainless steel and the metal counterpart. Cu-10Sn alloy is often used to improve the wear resistance of powder metallurgy 316L stainless steel. The influence of Cu-10Sn on sintering behavior and wear resistance of powder metallurgy 316L stainless steel was investigated. The parameters investigated included sintering temperature and volume percent of Cu-10Sn. A maximum relative density of 97% was achieved with 25% (in volume percent) Cu-10Sn content at a sintering temperature of 1300 ℃ for 60 min. The irregular and sharp angles of 316L stainless steel particles become round, and the pores are removed completely as a result of large amount of liquid phase formed during sintering. The minimum friction mass loss was achieved with 25% Cu-10Sn content.     

Influence of Marine Aerobic Biofilms on Corrosion of 316L Stainless Steel

The influence of marine aerobic biofilms on the corrosion of 316 L stainless steel(SS) in aerated and deaerated seawater was studied by electrochemical impedance spectroscopy(EIS), potentiodynamic polarisation curves, current-potential curves and scanning electron microscopy with energy-dispersive spectroscopy(SEM-EDS). EIS and SEM-EDS results showed that the aerobic biofilms inhibited 316 L SS corrosion within the test duration. Comparison of results under aerated and deaerated conditions revealed that O2 enhanced the inhibition efficiency of the aerobic biofilms. This result indicated that living cells were necessary for the aerobic biofilms to inhibit the corrosion of 316 L SS. Polarization curves indicated that the biofilms mainly inhibited anode action. Current-potential curves under deaerated conditions showed that electron transfer processes occurred between microorganisms and electrodes. Moreover, 316 L SS as an electron acceptor was protected from corrosion.