摘要：
为了提高冶金关键零部件热轧地下卷取机卷筒扇形板的力学性能并延长其使用寿命, 使用激光熔覆技术在2Cr12NiMoWV钢表面分别制备了两种铁基合金熔覆层; 利用金相显微镜观察熔覆层的显微组织; 利用显微硬度计测试熔覆层的硬度; 利用万能力学试验机测试熔覆层的力学性能; 利用SEM观察拉伸断口的显微组织; 利用EDS对断口的元素种类与含量进行分析。试验结果表明: 两种铁基合金熔覆层表面光滑平整, 无裂纹、气孔等明显缺陷, 均与基体钢形成了良好的冶金结合; 熔覆层的界面组织呈现定向快速凝固特征。其中A粉末制得的激光熔覆层硬度整体高于基体, 抗拉强度1 030 MPa, 屈服强度812 MPa, 延伸率10.1%, 断口形貌表明其断裂机制为脆性断裂; B粉末制得的激光熔覆层硬度整体略低于基体, 抗拉强度895 MPa, 屈服强度512 MPa, 延伸率26.5%, 断口形貌呈现出大量的韧窝, 断裂机制为韧性断裂。A粉末的激光熔覆组织硬度高、强度大, 塑性较差, B粉末的激光熔覆组织硬度较低、强度较差, 塑性极好。 To improve the mechanical properties of the hot rolled underground coiler reel fan-shaped plate of metallurgical key components and prolong its service life, two kinds of iron-based alloy cladding layers were prepared on the surface of 2Cr12NiMoWV steel by laser cladding technique.Observing the microstructure of the cladding layer using a metallographic microscope; testing the hardness of the cladding layer using a microhardness tester;The mechanical properties of the cladding layer were tested by a universal testing machine. The microstructure of the tensile fracture was observed by SEM. The element types and contents of the fracture were analyzed by EDS.The test results show that the surface of the two iron-based alloy cladding layers is smooth and flat, and there are no obvious defects such as cracks and pores, which form a good metallurgical bond with the base steel.The interfacial organization of the cladding layer exhibits a directional rapid solidification feature.The hardness of the laser cladding layer prepared by A powder is higher than that of the matrix, the tensile strength is 1030MPa, the yield strength is 812MPa, and the elongation is 10.1%. The fracture morphology indicates that the fracture mechanism is brittle fracture.The hardness of the laser cladding layer prepared by B powder is slightly lower than that of the matrix. The tensile strength is 895 MPa, the yield strength is 512 MPa, and the elongation is 26.5%. The fracture morphology shows a large number of dimples, and the fracture mechanism is ductile fracture. The laser cladding of A powder has high hardness, high strength and poor plasticity. The laser cladding of B powder has low hardness and poor strength, but the plasticity is excellent.
摘要：
采用光纤激光器对卷取机卷筒主轴常用的40CrNiMoA钢进行了激光淬火实验,采用金相显微镜观察试样表面的显微组织,采用维氏硬度计测试相变硬化层的显微硬度,采用立式万能摩擦磨损试验机评估试样的摩擦磨损性能,采用体视显微镜观察试样截面的宏观组织及磨损形貌,采用电化学工作站测试试样的耐蚀性能。结果表明:40CrNiMoA钢经激光淬火后,表面会出现一层相变硬化层,其显微组织主要为细小的马氏体、少量的残留奥氏体以及部分弥散的碳化物;硬化层深度约为200 μm,硬度值可达638.3~711.2 HV,约为基体的2.6~2.8倍;平均摩擦因数为0.506,与基体相比下降了42.5%,磨损量为1.3 mg,仅为基体的36.1%,其主要磨损机制为磨粒磨损;腐蚀电位为-0.497 V,自腐蚀电流密度为2.16789×10 -9 A/cm 2,与基体相比,腐蚀电位略有提高,而自腐蚀电流密度有所降低,耐腐蚀性能得到了较大提升。 In this study, a laser-quenching experiment is conducted on the 40CrNiMoA steel base material of a reel spindle using a fiber laser. Further, the microstructure of sample surface is observed using a metallographic microscope, the microhardness of the phase-transformation hardening zone is evaluated using a Vickers hardness tester, and the friction and wear properties of the sample are evaluated using a vertical universal friction-and-wear tester. The macroscopic structure of the sample cross-section and morphology after wear are observed using a stereo microscope, and the corrosion resistance of the sample is verified using an electrochemical workstation. The results denote that after laser quenching of the 40CrNiMoA steel, a phase-transformation hardening zone can be observed on the surface with a microstructure that is mainly characterized by fine martensite, a small amount of retained austenite, and partially dispersed carbides. The hardened layer exhibits a depth of approximately 200 μm, and the hardness can become 638.3--711.2 HV, which is approximately 2.6--2.8 times that of the substrate. The average friction coefficient is 0.506, which is 42.5% lower than that of the substrate. The amount of wear is 1.3 mg, which is only 36.1% of that of the substrate. Herein, the abrasive wear is observed to be the main wear mechanism. Furthermore, the corrosion voltage is -0.497 V, which is slightly higher than that of the substrate, while the self-corrosion current density is 2.16789×10 -9 A/cm 2, which is lower than that of the substrate. The corrosion resistance is considerably improved.
摘要：
目的提高锆合金在高温高压环境中耐动水腐蚀性能。方法利用多弧离子镀技术（MAIP）在Zr-4合金表面分别制备了Al2O3涂层和Cr/Ti AlN复合涂层,利用磁控溅射技术（MS）在Zr-4合金表面制备了Ti N涂层。通过堆外高压釜实验,对比研究了三种不同涂层的耐高温高压动水腐蚀性能,利用自动划痕仪检测膜基结合力,利用XRD分析涂层的物相成分,利用SEM观察涂层腐蚀前后的微观形貌,利用EDS对涂层元素种类与含量进行分析。结果多弧离子镀技术制备的Al2O3涂层和Cr/Ti Al N涂层致密度较高,但表面存在少量大颗粒与微孔洞;磁控溅射技术制备的Ti N涂层均匀平整,表面大颗粒较少。Al2O3涂层、Ti N涂层和Cr/Ti Al N涂层可承受的临界载荷分别为26、16、26.5 N。在实验条件下,Cr/Ti Al N涂层和Ti N涂层表面均发生了剥落或腐蚀现象,且这两种试样表面均检测出大量的Zr O2,而Al2O3涂层几乎未被破坏,基体得到了充分防护。结论利用多弧离子镀技术在Zr-4合金表面制备的Al2O3涂层和Cr/Ti Al N涂层的膜基结合力较高,利用磁控溅射技术制备的Ti N涂层的膜基结合性能较差,其中Al2O3涂层具备良好的耐腐蚀性能,在高温高压动水腐蚀环境中能够有效地保护锆合金基体。
作者机构：
[李涛; 樊湘芳; 周军] College of Mechanical Engineering, University of South China, Hengyang, 421001, China;[李怀林] Central Research Institute of State Power Investment Corporation, Beijing, 102209, China
通讯机构：
[Fan, X.] C;College of Mechanical Engineering, University of South China, Hengyang, China
期刊：
Journal of Nuclear Materials,2018年498:76-82 ISSN：0022-3115
通讯作者：
Zhou Jun;Fan Xiangfang
作者机构：
[Feng Zhendong; Fan Xiangfang; Zhou Jun; Fan, XF] Univ South China, Sch Mech Engn, Hengyang 421001, Peoples R China.;[Li Huanlin; Liu Yanhong] Cent Res Inst, Natl Elect Investment Grp, Beijing 102209, Peoples R China.
通讯机构：
[Zhou, J; Fan, XF] U;Univ South China, Sch Mech Engn, Hengyang 421001, Peoples R China.
关键词：
TiAlSiN coating;Zircaloy-4;Negative bias;High temperature oxidation behavior;Surface morphology;Adhesion strength
摘要：
TiAlSiN coatings were deposited on the nitrided Zircaloy-4 by multi-arc ion plating at -100 V, -200 V and -300 V. In this study, the high temperature oxidation behavior of coatings was tested by a box-type resistance furnace in air for 3 h at 800 degrees C; the macro-morphology of coatings was observed and analyzed by a zoom-stereo microscope; the micro-morphology of coatings was analyzed by a scanning electron microscopy (SEM), and the chemical elements of samples were analyzed by an energy dispersive spectroscopy(EDS); the adhesion strength of the coating to the substrate was measured by an automatic scratch tester; and the phases of coatings were analyzed by an X-ray diffractometer(XRD). Results show that the coating deposited at -100 V shows better high temperature oxidation resistance behavior, at the same time, Al elements contained in the coating is of the highest amount, meanwhile, the adhesion strength of the coating to the substrate is the highest, which is 33N. As the bias increases, high temperature oxidation resistance behavior of the coating weakens first and then increases, the amount of large particles on the surface of the coating increases first and then decreases whereas the density of the coating decreases first and then increases, and adhesion strength of the coating to the substrate increases first and then weakens. The coating's quality is relatively poor when the bias is -200 V. (C) 2017 Published by Elsevier B.V.
