Improved Mechanical Properties of Friction Stir Welded 1500 MPa Martensitic Steel Joints with Additional Water Cooling

Shuhao Zhu,Pengcheng Zhu,Binbin Wang,Liang Zhang,Yufeng Sun,Shaokang Guan 대한금속·재료학회 2024 METALS AND MATERIALS International Vol.30 No.1

This study proposes a method to improve the mechanical strength of martensitic welded joints by minimizing the effect ofmartensitic tempering. The high-strength martensitic steel plate exhibiting a tensile strength of 1500 MPa was successfullyjoined in this study utilizing additional water-cooling by friction stir welding (FSW) technique. Concurrently, conventionalair-cooled welded joints were produced utilizing identical welding parameters for comparison. Notwithstanding the macrostructureof both FSW joints was similar, the air-cooled joint contained a larger stir zone (SZ) and wider heat-affectedzone (HAZ). The air-cooled joint SZ exhibited a microstructure featuring coarse martensite, while the water-cooled jointSZ displayed a microstructure consisting of fine martensite. The degree of self-tempering of the martensite in the HAZ wassignificantly reduced, together with fewer and finer carbide particles than in the HAZ of air-cooled joints, by applying watercooling. The tensile test results indicated that the water-cooled FSW joint showed a significant improvement (23.6%) inultimate tensile strength compared to its air-cooled counterparts.

A SMOOTHING NEWTON METHOD FOR NCP BASED ON A NEW CLASS OF SMOOTHING FUNCTIONS

Zhu, Jianguang,Hao, Binbin The Korean Society for Computational and Applied M 2014 Journal of applied mathematics & informatics Vol.32 No.1

A new class of smoothing functions is introduced in this paper, which includes some important smoothing complementarity functions as its special cases. Based on this new smoothing function, we proposed a smoothing Newton method. Our algorithm needs only to solve one linear system of equations. Without requiring the nonemptyness and boundedness of the solution set, the proposed algorithm is proved to be globally convergent. Numerical results indicate that the smoothing Newton method based on the new proposed class of smoothing functions with ${\theta}{\in}(0,1)$ seems to have better numerical performance than those based on some other important smoothing functions, which also demonstrate that our algorithm is promising.

Nepenthes pitcher-inspired lubricant-infused slippery surface with superior anti-corrosion durability, hot water repellency and scratch resistance

Binbin Zhang,Weichen Xu,Qingjun Zhu,Fang Guan,Yimeng Zhang 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.107 No.-

Nepenthes pitcher-inspired slippery surface provides an alternative strategy to overcome the shortcomingsof the current superhydrophobic surfaces such as thermal–mechanical stability and functional durability. Herein, we fabricate a lubricant-infused slippery surface (LISS) through micro-nano structurebuilding, low surface energy molecular grafting and perfluoropolyethers (PFPE) lubricant oil infusion. The surface morphologies, chemical compositions, wettability, dynamic liquids movement, selfcleaning,anti-corrosion behavior, and thermal–mechanical stability were investigated and analyzed. The electrochemical impedance spectroscopy (EIS) results reveal that the fabricated LISS exhibitsenhanced Rct and |Z|0.01Hz values with 2 orders of magnitude higher even after 30 days immersion,demonstrating outstanding long-lasting anti-corrosion properties. Besides, the LISS also exhibits superiorcapacities of hot water repellency (90 C water droplets) and scratching resistance. We believe theseresults have significant implications for understanding the design and multi-functional applications ofbiomimetic liquid-infused slippery materials.

A SMOOTHING NEWTON METHOD FOR NCP BASED ON A NEW CLASS OF SMOOTHING FUNCTIONS

Jianguang Zhu,Binbin Hao 한국전산응용수학회 2014 Journal of applied mathematics & informatics Vol.32 No.1

A new class of smoothing functions is introduced in this pa- per, which includes some important smoothing complementarity functions as its special cases. Based on this new smoothing function, we proposed a smoothing Newton method. Our algorithm needs only to solve one linear system of equations. Without requiring the nonemptyness and bounded- ness of the solution set, the proposed algorithm is proved to be globally convergent. Numerical results indicate that the smoothing Newton method based on the new proposed class of smoothing functions with θ∊(0,1) seems to have better numerical performance than those based on some other important smoothing functions, which also demonstrate that our al- gorithm is promising.

Numerical investigation of two-phase flow characteristics in multiphase pump with split vane impellers

Yi Shi,Hongwu Zhu,Binbin Yin,Ruiting Xu,Jiate Zhang 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.4

Multiphase pump is a cost-effective option for subsea oil and gas field development. The ability to handle different inlet gas volume fractions (GVFs) especially high inlet GVF is critical to the development of pump performance. In this study, the two-phase flow characteristics in normal impeller and split vane impeller at different inlet GVFs were investigated by steady numerical simulations. The gas distribution on blade-to-blade plane and meridional flow channel at different inlet GVFs were analyzed and compared. Gas accumulation area and movement characteristics of the gas-liquid flow in impeller flow passage were also pointed out by unsteady simulations. Experimental results of the pump differential pressure were compared with the numerical simulation results, to validate the accuracy of numerical simulation method. The flow characteristics in pump with modified impeller and its performance at different inlet GVFs were both compared with that of the normal impeller. The steady simulation results of normal impeller in different inlet GVFs show that gas concentrating area in the flow passage increases as inlet GVF grows. The unsteady simulation results indicate that gas pocket firstly occurs on the pressure side of impeller, then moves to the suction side in the middle area of blade and finally transfers to outlet of impeller and disappears. The errors between numerical simulation results and experiment data are below 10 %, which validated the feasibility of the numerical simulation method. Simulation results on the split vane impeller demonstrate that the gas accumulation area in flow passage of the modified impeller is dramatically decreased compared to that of the normal impeller. The performance of the modified impeller is generally better than the normal impeller especially in high inlet GVF conditions.

Photocatalytic degradation of dyes using dioxygen activated by supported metallophthalocyanine under visible light irradiation

Yuyuan Yao,Zhenfu Huang,Binbin Zheng,Shun Zhu,Wangyang Lu,Wenxing Chen,Haixiang Chen 한국물리학회 2013 Current Applied Physics Vol.13 No.8

Zinc tetraaminophthalocyanine (Zn-TAPc) modified by cyanuric chloride was immobilized on silk fibers by covalent bond to obtain a supported photocatalyst (Zn-TDTAPc-SF). The photocatalytic degradation of acid orange II based on Zn-TDTAPc-SF/O2 system was investigated under visible light irradiation (λ ≥ 400 nm). The results indicated that Zn-TDTAPc-SF exhibited excellent photocatalytic performance in the presence of O2 under visible light irradiation. In 6 h, more than 93% of acid orange II (AO2) in Zn-TDTAPc-SF/O2 systemwas eliminated at initial pH 5 under visible light irradiation, and Zn-TDTAPc-SF still remained effective in repetitive fives cycles. Furthermore, NaCl played a positive role in the catalytic reaction, different from the negative one observed in homogeneous catalysis, and the reaction can proceed in a more wide pH range from acidic to alkaline. Based on the analysis of FT-IR and Gas Chromatography/Mass Spectrometry (GCeMS), AO2 was mainly converted into some small molecular biodegradable aliphatic carboxylic compounds such as maleic acid, fumaric acid, succinic acid, etc. The photodegradation mechanism for the evolution of AO2 was proposed by Electron Paramagnetic Resonance (EPR) spectra.

Review of research on safety control of seismic wave and shock wave induced by underwater blasting

Yaxiong Peng,Li Wu,Ying Su,Binbin Zhu,Chunhui Chen,Bo Li 한국자원공학회 2017 Geosystem engineering Vol.20 No.3

The safety control methods and indexes of seismic wave and shock wave induced by underwater blasting are, respectively, elaborated in this paper. The single-factor and the double-factor safety control taking both vibration velocity and vibration frequency into consideration are comprehensively analyzed, and the weaknesses of the application scopes of both criteria in the safety performance evaluation of blasting vibration are discussed. Relative researches on the duration time of blasting are introduced, and the duration time for blasting is proposed to be embraced in the scope of safety control. Besides, the research progresses of safety control of water shock wave and aerial shock wave are, respectively, introduced, and the weaknesses of the above methods in the application to underwater blasting engineering are analyzed. Based on the analysis of the adverse effects of seismic wave and shock wave, the new idea to study the synergistic effects of both kinds of waves is put forward, and the comprehensive safety control method which includes both seismic wave and shock wave remains to be developed.