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排序方式: 共有2312条查询结果,搜索用时 28 毫秒
1.
《Ceramics International》2022,48(12):17412-17424
The aim of this study is to investigate the physicochemical and thermophysical properties of CaO–TiO2–SiO2–Na3AlF6 based electrode coating developed for the welding of advanced ultra-supercritical (AUSC) thermal power plant components. The extreme vertices approach has been used to create twenty-six electrode coating compositions. Various physicochemical and thermophysical properties were characterized using experiments. The coating properties are essential in ensuring sound weld with desirable in-service performance. The developed coating's structural behavior was analyzed using Fourier transformation infrared spectroscopy (FTIR) and X-ray diffraction (XRD). In addition, regression analysis was carried out to evaluate the influence of coating constituents. Individual constituents and their interaction were found to have a prominent role in influencing the physicochemical and thermophysical properties. 相似文献
2.
A.A. Khalili Tabas B. Beidokhti A.R. Kiani-Rashid 《International Journal of Hydrogen Energy》2021,46(1):1012-1022
Different heat treatment cycles were designed in order to investigate the effect of microstructural changes on hydrogen induced cracking resistance (HIC) and mechanical properties of the electric resistance welded steel. The heat treating of the as-welded specimen improved the ductility and impact toughness. After heat treatment, the uniform hardness profile was obtained for the welded specimens. The removal of local hard zones reduced the risk of HIC. The chemical composition and clustering of inclusions have a deleterious effect on cracking resistance in the H2S environment. Aluminosilicate compounds and MnS inclusions were favorite sites for HIC. The most promising post weld heat treatment for improving mechanical properties and the resistance to HIC was the application of two-cycle quenching followed by tempering. 相似文献
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The purpose of this study was to evaluate a variety of post weld heat treatment temperatures on the fatigue performance of Friction Stir Welded Ti–6Al–4V joints in order to identify an optimal post weld heat treatment condition. Microstructure, microhardness and tensile properties were also evaluated for each heat treatment condition to provide additional insight into the fatigue results obtained. Four heat treatment temperatures were evaluated, 760, 816, 871 and 927 °C. In general, it was found that that hardness and strength decreased with heat treatment temperature, but ductility and fatigue performance improved. It is recommended that a high heat treatment temperature be used on Ti FSW’s to obtain the best combination of strength, ductility and fatigue performance. 相似文献
5.
《Ceramics International》2020,46(7):8601-8614
This paper investigates the physicochemical and thermo-physical properties of CaO–CaF2–SiO2 and CaO–TiO2–SiO2 based electrode coating for welding offshore structures. Twenty-one electrode coating compositions have been formulated using extreme vertices design method. The coating was crushed to powder form. The powder was characterized for weight loss, density, specific heat, enthalpy, thermal conductivity, diffusivity, and specific heat. Coating's structural analysis was done using X-Ray Diffraction and Fourier transformation. X-Ray Fluorescence, Thermogravimetric Analyzer, and Hot disc have been used to characterize the coating mixture. The regression analysis has been used to study the effect of individual constituents and their binary, tertiary interactions on the properties. The obtained output of properties has been optimized using multi-response optimization. 相似文献
6.
A novel non-keyhole friction stir welding technique was proposed to weld the butt joint of 6061-T6 aluminum alloy with the thickness of 6 mm. A sound joint was obtained by this technique, simultaneously eliminating the flash, shoulder mark and keyhole defects. The sleeve directly affected zone (SDAZ) and the sleeve indirectly affected zone (SIAZ) were divided into the joint according to the plunging position of the hollow sleeve. The lack of root penetration defect was avoided when the plunging depth of the hollow sleeve was only 4.2 mm, because the hollow part inside the sleeve improved the material flow below the sleeve. An S-shaped line was left at the SIAZ, and the height of it had the minimum value of 1.47 mm at 20 mm/min. Whether the failure location of the joint was in SIAZ/SDAZ or the heat-affected zone (HAZ) depended on the height and bonding strength of the S-shaped line. The joint fracture location changed from the SIAZ/SDAZ at 35 mm/min to the HAZ at 20 and 30 mm/min. The maximum tensile strength of 224.3 MPa was obtained at 30 mm/min which was 73.7% of that of the base material. The fracture surface morphology exhibited the typical ductile fracture. 相似文献
7.
钛合金以其高比强度、优良的耐海水腐蚀性能,成为未来船舶选材的热点。综述了海水管路用钛合金的材料选用、焊接技术、弯管技术、腐蚀防护以及防海生物污损等方面的研究工作进展并进行分析,证明钛合金是船舶海水管路系统的理想选择,以期推动钛合金在船舶海水管路的推广和应用。 相似文献
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Target design methodologies (DfX) were developed to cope with specific engineering design issues such as cost-effectiveness, manufacturability, assemblability, maintainability, among others. However, DfX methodologies are undergoing the lack of real integration with 3D CAD systems. Their principles are currently applied downstream of the 3D modelling by following the well-known rules available from the literature and engineers’ know-how (tacit internal knowledge).This paper provides a method to formalize complex DfX engineering knowledge into explicit knowledge that can be reused for Advanced Engineering Informatics to aid designers and engineers in developing mechanical products. This research work wants to define a general method (ontology) able to couple DfX design guidelines (engineering knowledge) with geometrical product features of a product 3D model (engineering parametric data). A common layer for all DfX methods (horizontal) and dedicated layers for each DfX method (vertical) allow creating the suitable ontology for the systematic collection of the DfX rules considering each target. Moreover, the proposed framework is the first step for developing (future work) a software tool to assist engineers and designers during product development (3D CAD modelling).A design for assembly (DfA) case study shows how to collect assembly rules in the given framework. It demonstrates the applicability of the CAD-integrated DfX system in the mechanical design of a jig-crane. Several benefits are recognized: (i) systematic collection of DfA rules for informatics development, (ii) identification of assembly issues in the product development process, and (iii) reduction of effort and time during the design review. 相似文献
10.
高耐磨合金柱及专用焊接设备是一种新型的磨损防护系统,它是在易磨损工作面上采用特殊焊接方式(无需任何焊条)焊接高耐磨合金柱。该设备的研制成功可使易磨损工作部件的使用寿命提高3~4倍,可从人力、物力、电力等方面大大降低工业成本及辅助作业成本,降低劳动强度,提高生产效率。试验证明,高耐磨合金柱及专用焊接设备是一种高效、实用、低成本的提高设备耐磨性能的方法和设备。 相似文献